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  • spliiting code in java-don't know what's wrong [closed]

    - by ???? ?????
    I'm writing a code to split a file into many files with a size specified in the code, and then it will join these parts later. The problem is with the joining code, it doesn't work and I can't figure what is wrong! This is my code: import java.io.*; import java.util.*; public class StupidSplit { static final int Chunk_Size = 10; static int size =0; public static void main(String[] args) throws IOException { String file = "b.txt"; int chunks = DivideFile(file); System.out.print((new File(file)).delete()); System.out.print(JoinFile(file, chunks)); } static boolean JoinFile(String fname, int nChunks) { /* * Joins the chunks together. Chunks have been divided using DivideFile * function so the last part of filename will ".partxxxx" Checks if all * parts are together by matching number of chunks found against * "nChunks", then joins the file otherwise throws an error. */ boolean successful = false; File currentDirectory = new File(System.getProperty("user.dir")); // File[] fileList = currentDirectory.listFiles(); /* populate only the files having extension like "partxxxx" */ List<File> lst = new ArrayList<File>(); // Arrays.sort(fileList); for (File file : fileList) { if (file.isFile()) { String fnm = file.getName(); int lastDot = fnm.lastIndexOf('.'); // add to list which match the name given by "fname" and have //"partxxxx" as extension" if (fnm.substring(0, lastDot).equalsIgnoreCase(fname) && (fnm.substring(lastDot + 1)).substring(0, 4).equals("part")) { lst.add(file); } } } /* * sort the list - it will be sorted by extension only because we have * ensured that list only contains those files that have "fname" and * "part" */ File[] files = (File[]) lst.toArray(new File[0]); Arrays.sort(files); System.out.println("size ="+files.length); System.out.println("hello"); /* Ensure that number of chunks match the length of array */ if (files.length == nChunks-1) { File ofile = new File(fname); FileOutputStream fos; FileInputStream fis; byte[] fileBytes; int bytesRead = 0; try { fos = new FileOutputStream(ofile,true); for (File file : files) { fis = new FileInputStream(file); fileBytes = new byte[(int) file.length()]; bytesRead = fis.read(fileBytes, 0, (int) file.length()); assert(bytesRead == fileBytes.length); assert(bytesRead == (int) file.length()); fos.write(fileBytes); fos.flush(); fileBytes = null; fis.close(); fis = null; } fos.close(); fos = null; } catch (FileNotFoundException fnfe) { System.out.println("Could not find file"); successful = false; return successful; } catch (IOException ioe) { System.out.println("Cannot write to disk"); successful = false; return successful; } /* ensure size of file matches the size given by server */ successful = (ofile.length() == StupidSplit.size) ? true : false; } else { successful = false; } return successful; } static int DivideFile(String fname) { File ifile = new File(fname); FileInputStream fis; String newName; FileOutputStream chunk; //int fileSize = (int) ifile.length(); double fileSize = (double) ifile.length(); //int nChunks = 0, read = 0, readLength = Chunk_Size; int nChunks = 0, read = 0, readLength = Chunk_Size; byte[] byteChunk; try { fis = new FileInputStream(ifile); StupidSplit.size = (int)ifile.length(); while (fileSize > 0) { if (fileSize <= Chunk_Size) { readLength = (int) fileSize; } byteChunk = new byte[readLength]; read = fis.read(byteChunk, 0, readLength); fileSize -= read; assert(read==byteChunk.length); nChunks++; //newName = fname + ".part" + Integer.toString(nChunks - 1); newName = String.format("%s.part%09d", fname, nChunks - 1); chunk = new FileOutputStream(new File(newName)); chunk.write(byteChunk); chunk.flush(); chunk.close(); byteChunk = null; chunk = null; } fis.close(); System.out.println(nChunks); // fis = null; } catch (FileNotFoundException fnfe) { System.out.println("Could not find the given file"); System.exit(-1); } catch (IOException ioe) { System.out .println("Error while creating file chunks. Exiting program"); System.exit(-1); }System.out.println(nChunks); return nChunks; } } }

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  • Project Euler #15

    - by Aistina
    Hey everyone, Last night I was trying to solve challenge #15 from Project Euler: Starting in the top left corner of a 2×2 grid, there are 6 routes (without backtracking) to the bottom right corner. How many routes are there through a 20×20 grid? I figured this shouldn't be so hard, so I wrote a basic recursive function: const int gridSize = 20; // call with progress(0, 0) static int progress(int x, int y) { int i = 0; if (x < gridSize) i += progress(x + 1, y); if (y < gridSize) i += progress(x, y + 1); if (x == gridSize && y == gridSize) return 1; return i; } I verified that it worked for a smaller grids such as 2×2 or 3×3, and then set it to run for a 20×20 grid. Imagine my surprise when, 5 hours later, the program was still happily crunching the numbers, and only about 80% done (based on examining its current position/route in the grid). Clearly I'm going about this the wrong way. How would you solve this problem? I'm thinking it should be solved using an equation rather than a method like mine, but that's unfortunately not a strong side of mine. Update: I now have a working version. Basically it caches results obtained before when a n×m block still remains to be traversed. Here is the code along with some comments: // the size of our grid static int gridSize = 20; // the amount of paths available for a "NxM" block, e.g. "2x2" => 4 static Dictionary<string, long> pathsByBlock = new Dictionary<string, long>(); // calculate the surface of the block to the finish line static long calcsurface(long x, long y) { return (gridSize - x) * (gridSize - y); } // call using progress (0, 0) static long progress(long x, long y) { // first calculate the surface of the block remaining long surface = calcsurface(x, y); long i = 0; // zero surface means only 1 path remains // (we either go only right, or only down) if (surface == 0) return 1; // create a textual representation of the remaining // block, for use in the dictionary string block = (gridSize - x) + "x" + (gridSize - y); // if a same block has not been processed before if (!pathsByBlock.ContainsKey(block)) { // calculate it in the right direction if (x < gridSize) i += progress(x + 1, y); // and in the down direction if (y < gridSize) i += progress(x, y + 1); // and cache the result! pathsByBlock[block] = i; } // self-explanatory :) return pathsByBlock[block]; } Calling it 20 times, for grids with size 1×1 through 20×20 produces the following output: There are 2 paths in a 1 sized grid 0,0110006 seconds There are 6 paths in a 2 sized grid 0,0030002 seconds There are 20 paths in a 3 sized grid 0 seconds There are 70 paths in a 4 sized grid 0 seconds There are 252 paths in a 5 sized grid 0 seconds There are 924 paths in a 6 sized grid 0 seconds There are 3432 paths in a 7 sized grid 0 seconds There are 12870 paths in a 8 sized grid 0,001 seconds There are 48620 paths in a 9 sized grid 0,0010001 seconds There are 184756 paths in a 10 sized grid 0,001 seconds There are 705432 paths in a 11 sized grid 0 seconds There are 2704156 paths in a 12 sized grid 0 seconds There are 10400600 paths in a 13 sized grid 0,001 seconds There are 40116600 paths in a 14 sized grid 0 seconds There are 155117520 paths in a 15 sized grid 0 seconds There are 601080390 paths in a 16 sized grid 0,0010001 seconds There are 2333606220 paths in a 17 sized grid 0,001 seconds There are 9075135300 paths in a 18 sized grid 0,001 seconds There are 35345263800 paths in a 19 sized grid 0,001 seconds There are 137846528820 paths in a 20 sized grid 0,0010001 seconds 0,0390022 seconds in total I'm accepting danben's answer, because his helped me find this solution the most. But upvotes also to Tim Goodman and Agos :) Bonus update: After reading Eric Lippert's answer, I took another look and rewrote it somewhat. The basic idea is still the same but the caching part has been taken out and put in a separate function, like in Eric's example. The result is some much more elegant looking code. // the size of our grid const int gridSize = 20; // magic. static Func<A1, A2, R> Memoize<A1, A2, R>(this Func<A1, A2, R> f) { // Return a function which is f with caching. var dictionary = new Dictionary<string, R>(); return (A1 a1, A2 a2) => { R r; string key = a1 + "x" + a2; if (!dictionary.TryGetValue(key, out r)) { // not in cache yet r = f(a1, a2); dictionary.Add(key, r); } return r; }; } // calculate the surface of the block to the finish line static long calcsurface(long x, long y) { return (gridSize - x) * (gridSize - y); } // call using progress (0, 0) static Func<long, long, long> progress = ((Func<long, long, long>)((long x, long y) => { // first calculate the surface of the block remaining long surface = calcsurface(x, y); long i = 0; // zero surface means only 1 path remains // (we either go only right, or only down) if (surface == 0) return 1; // calculate it in the right direction if (x < gridSize) i += progress(x + 1, y); // and in the down direction if (y < gridSize) i += progress(x, y + 1); // self-explanatory :) return i; })).Memoize(); By the way, I couldn't think of a better way to use the two arguments as a key for the dictionary. I googled around a bit, and it seems this is a common solution. Oh well.

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  • Confusing Java syntax...

    - by posfan12
    I'm trying to convert the following code (from Wikipedia) from Java to JavaScript: /* * 3 June 2003, [[:en:User:Cyp]]: * Maze, generated by my algorithm * 24 October 2006, [[:en:User:quin]]: * Source edited for clarity * 25 January 2009, [[:en:User:DebateG]]: * Source edited again for clarity and reusability * 1 June 2009, [[:en:User:Nandhp]]: * Source edited to produce SVG file when run from the command-line * * This program was originally written by [[:en:User:Cyp]], who * attached it to the image description page for an image generated by * it on en.wikipedia. The image was licensed under CC-BY-SA-3.0/GFDL. */ import java.awt.*; import java.applet.*; import java.util.Random; /* Define the bit masks */ class Constants { public static final int WALL_ABOVE = 1; public static final int WALL_BELOW = 2; public static final int WALL_LEFT = 4; public static final int WALL_RIGHT = 8; public static final int QUEUED = 16; public static final int IN_MAZE = 32; } public class Maze extends java.applet.Applet { /* The width and height (in cells) of the maze */ private int width; private int height; private int maze[][]; private static final Random rnd = new Random(); /* The width in pixels of each cell */ private int cell_width; /* Construct a Maze with the default width, height, and cell_width */ public Maze() { this(20,20,10); } /* Construct a Maze with specified width, height, and cell_width */ public Maze(int width, int height, int cell_width) { this.width = width; this.height = height; this.cell_width = cell_width; } /* Initialization method that will be called when the program is * run from the command-line. Maze will be written as SVG file. */ public static void main(String[] args) { Maze m = new Maze(); m.createMaze(); m.printSVG(); } /* Initialization method that will be called when the program is * run as an applet. Maze will be displayed on-screen. */ public void init() { createMaze(); } /* The maze generation algorithm. */ private void createMaze(){ int x, y, n, d; int dx[] = { 0, 0, -1, 1 }; int dy[] = { -1, 1, 0, 0 }; int todo[] = new int[height * width], todonum = 0; /* We want to create a maze on a grid. */ maze = new int[width][height]; /* We start with a grid full of walls. */ for (x = 0; x < width; ++x) { for (y = 0; y < height; ++y) { if (x == 0 || x == width - 1 || y == 0 || y == height - 1) { maze[x][y] = Constants.IN_MAZE; } else { maze[x][y] = 63; } } } /* Select any square of the grid, to start with. */ x = 1 + rnd.nextInt (width - 2); y = 1 + rnd.nextInt (height - 2); /* Mark this square as connected to the maze. */ maze[x][y] &= ~48; /* Remember the surrounding squares, as we will */ for (d = 0; d < 4; ++d) { if ((maze[][d][][d] & Constants.QUEUED) != 0) { /* want to connect them to the maze. */ todo[todonum++] = ((x + dx[d]) << Constants.QUEUED) | (y + dy[d]); maze[][d][][d] &= ~Constants.QUEUED; } } /* We won't be finished until all is connected. */ while (todonum > 0) { /* We select one of the squares next to the maze. */ n = rnd.nextInt (todonum); x = todo[n] >> 16; /* the top 2 bytes of the data */ y = todo[n] & 65535; /* the bottom 2 bytes of the data */ /* We will connect it, so remove it from the queue. */ todo[n] = todo[--todonum]; /* Select a direction, which leads to the maze. */ do { d = rnd.nextInt (4); } while ((maze[][d][][d] & Constants.IN_MAZE) != 0); /* Connect this square to the maze. */ maze[x][y] &= ~((1 << d) | Constants.IN_MAZE); maze[][d][][d] &= ~(1 << (d ^ 1)); /* Remember the surrounding squares, which aren't */ for (d = 0; d < 4; ++d) { if ((maze[][d][][d] & Constants.QUEUED) != 0) { /* connected to the maze, and aren't yet queued to be. */ todo[todonum++] = ((x + dx[d]) << Constants.QUEUED) | (y + dy[d]); maze[][d][][d] &= ~Constants.QUEUED; } } /* Repeat until finished. */ } /* Add an entrance and exit. */ maze[1][1] &= ~Constants.WALL_ABOVE; maze[width - 2][height - 2] &= ~Constants.WALL_BELOW; } /* Called by the applet infrastructure to display the maze on-screen. */ public void paint(Graphics g) { drawMaze(g); } /* Called to write the maze to an SVG file. */ public void printSVG() { System.out.format("<svg width=\"%d\" height=\"%d\" version=\"1.1\"" + " xmlns=\"http://www.w3.org/2000/svg\">\n", width*cell_width, height*cell_width); System.out.println(" <g stroke=\"black\" stroke-width=\"1\"" + " stroke-linecap=\"round\">"); drawMaze(null); System.out.println(" </g>\n</svg>"); } /* Main maze-drawing loop. */ public void drawMaze(Graphics g) { int x, y; for (x = 1; x < width - 1; ++x) { for (y = 1; y < height - 1; ++y) { if ((maze[x][y] & Constants.WALL_ABOVE) != 0) drawLine( x * cell_width, y * cell_width, (x + 1) * cell_width, y * cell_width, g); if ((maze[x][y] & Constants.WALL_BELOW) != 0) drawLine( x * cell_width, (y + 1) * cell_width, (x + 1) * cell_width, (y + 1) * cell_width, g); if ((maze[x][y] & Constants.WALL_LEFT) != 0) drawLine( x * cell_width, y * cell_width, x * cell_width, (y + 1) * cell_width, g); if ((maze[x][y] & Constants.WALL_RIGHT) != 0) drawLine((x + 1) * cell_width, y * cell_width, (x + 1) * cell_width, (y + 1) * cell_width, g); } } } /* Draw a line, either in the SVG file or on the screen. */ public void drawLine(int x1, int y1, int x2, int y2, Graphics g) { if ( g != null ) g.drawLine(x1, y1, x2, y2); else System.out.format(" <line x1=\"%d\" y1=\"%d\"" + " x2=\"%d\" y2=\"%d\" />\n", x1, y1, x2, y2); } } Anyway, I was chugging along fairly quickly when I came to a bit that I just don't understand: /* Remember the surrounding squares, as we will */ for (var d = 0; d < 4; ++d) { if ((maze[][d][][d] & Constants.QUEUED) != 0) { /* want to connect them to the maze. */ todo[todonum++] = ((x + dx[d]) << Constants.QUEUED) | (y + dy[d]); maze[][d][][d] &= ~Constants.QUEUED; } } What I don't get is why there are four sets of brackets following the "maze" parameter instead of just two, since "maze" is a two dimensional array, not a four dimensional array. I'm sure there's a good reason for this. Problem is, I just don't get it. Thanks!

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  • How to display a JSON error message?

    - by Tiny Giant Studios
    I'm currently developing a tumblr theme and have built a jQuery JSON thingamabob that uses the Tumblr API to do the following: The user would click on the "post type" link (e.g. Video Posts), at which stage jQuery would use JSON to grab all the posts that's related to that type and then dynamically display them in a designated area. Now everything works absolutely peachy, except that with Tumblr being Tumblr and their servers taking a knock every now and then, the Tumblr API thingy is sometimes offline. Now I can't foresee when this function will be down, which is why I want to display some generic error message if JSON (for whatever reason) was unable to load the post. You'll see I've already written some code to show an error message when jQuery can't find any posts related to that post type BUT it doesn't cover any server errors. Note: I sometimes get this error: Failed to load resource: the server responded with a status of 503 (Service Temporarily Unavailable) It is for this 503 Error message that I need to write some code, but I'm slightly clueless :) Here's the jQuery JSON code: $('ul.right li').find('a').click(function() { var postType = this.className; var count = 0; byCategory(postType); return false; function byCategory(postType, callback) { $.getJSON('{URL}/api/read/json?type=' + postType + '&callback=?', function(data) { var article = []; $.each(data.posts, function(i, item) { // i = index // item = data for a particular post switch(item.type) { case 'photo': article[i] = '<div class="post_wrap"><div class="photo" style="padding-bottom:5px;">' + '<a href="' + item.url + '" title="{Title}" class="type_icon"><img src="http://static.tumblr.com/ewjv7ap/XSTldh6ds/photo_icon.png" alt="type_icon"/></a>' + '<a href="' + item.url + '" title="{Title}"><img src="' + item['photo-url-500'] + '"alt="image" /></a></div></div>'; count = 1; break; case 'video': article[i] = '<div class="post_wrap"><div class="video" style="padding-bottom:5px;">' + '<a href="' + item.url + '" title="{Title}" class="type_icon">' + '<img src="http://static.tumblr.com/ewjv7ap/nuSldhclv/video_icon.png" alt="type_icon"/></a>' + '<span style="margin: auto;">' + item['video-player'] + '</span>' + '</div></div>'; count = 1; break; case 'audio': if (use_IE == true) { article[i] = '<div class="post_wrap"><div class="regular">' + '<a href="' + item.url + '" title="{Title}" class="type_icon"><img src="http://static.tumblr.com/ewjv7ap/R50ldh5uj/audio_icon.png" alt="type_icon"/></a>' + '<h3><a href="' + item.url + '">' + item['id3-artist'] +' - ' + item['id3-title'] + '</a></h3>' + '</div></div>'; } else { article[i] = '<div class="post_wrap"><div class="regular">' + '<a href="' + item.url + '" title="{Title}" class="type_icon"><img src="http://static.tumblr.com/ewjv7ap/R50ldh5uj/audio_icon.png" alt="type_icon"/></a>' + '<h3><a href="' + item.url + '">' + item['id3-artist'] +' - ' + item['id3-title'] + '</a></h3><div class="player">' + item['audio-player'] + '</div>' + '</div></div>'; }; count = 1; break; case 'regular': article[i] = '<div class="post_wrap"><div class="regular">' + '<a href="' + item.url + '" title="{Title}" class="type_icon"><img src="http://static.tumblr.com/ewjv7ap/dwxldhck1/regular_icon.png" alt="type_icon"/></a><h3><a href="' + item.url + '">' + item['regular-title'] + '</a></h3><div class="description_container">' + item['regular-body'] + '</div></div></div>'; count = 1; break; case 'quote': article[i] = '<div class="post_wrap"><div class="quote">' + '<a href="' + item.url + '" title="{Title}" class="type_icon"><img src="http://static.tumblr.com/ewjv7ap/loEldhcpr/quote_icon.png" alt="type_icon"/></a><blockquote><h3><a href="' + item.url + '" title="{Title}">' + item['quote-text'] + '</a></h3></blockquote><cite>- ' + item['quote-source'] + '</cite></div></div>'; count = 1; break; case 'conversation': article[i] = '<div class="post_wrap"><div class="chat">' + '<a href="' + item.url + '" title="{Title}" class="type_icon"><img src="http://static.tumblr.com/ewjv7ap/MVuldhcth/conversation_icon.png" alt="type_icon"/></a><h3><a href="' + item.url + '">' + item['conversation-title'] + '</a></h3></div></div>'; count = 1; break; case 'link': article[i] = '<div class="post_wrap"><div class="link">' + '<a href="' + item.url + '" title="{Title}" class="type_icon"><img src="http://static.tumblr.com/ewjv7ap/EQGldhc30/link_icon.png" alt="type_icon"/></a><h3><a href="' + item['link-url'] + '" target="_blank">' + item['link-text'] + '</a></h3></div></div>'; count = 1; break; default: alert('No Entries Found.'); }; }) // end each if (!(count == 0)) { $('#content_right') .hide('fast') .html('<div class="first_div"><span class="left_corner"></span><span class="right_corner"></span><h2>Displaying ' + postType + ' Posts Only</h2></div>' + article.join('')) .slideDown('fast') } else { $('#content_right') .hide('fast') .html('<div class="first_div"><span class="left_corner"></span><span class="right_corner"></span><h2>Hmmm, currently there are no ' + postType + ' posts to display</h2></div>') .slideDown('fast') } // end getJSON }); // end byCategory } }); If you'd like to see the demo in action, check out Elegantem but do note that everything might work absolutely fine for you (or not), depending on Tumblr's temperament.

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  • Maze not generating properly. Out of bounds exception. need quick fix

    - by Dan Joseph Porcioncula
    My maze generator seems to have a problem. I am trying to generate something like the maze from http://mazeworks.com/mazegen/mazetut/index.htm . My program displays this http://a1.sphotos.ak.fbcdn.net/hphotos-ak-snc7/s320x320/374060_426350204045347_100000111130260_1880768_1572427285_n.jpg and the error Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: -1 at Grid.genRand(Grid.java:73) at Grid.main(Grid.java:35) How do I fix my generator program? import java.awt.*; import java.awt.Color; import java.awt.Component; import java.awt.Graphics; import javax.swing.*; import java.util.ArrayList; public class Grid extends Canvas { Cell[][] maze; int size; int pathSize; double width, height; ArrayList<int[]> coordinates = new ArrayList<int[]>(); public Grid(int size, int h, int w) { this.size = size; maze = new Cell[size][size]; for(int i = 0; i<size; i++){ for(int a =0; a<size; a++){ maze[i][a] = new Cell(); } } setPreferredSize(new Dimension(h, w)); } public static void main(String[] args) { JFrame y = new JFrame(); y.setLayout(new BorderLayout()); Grid f = new Grid(25, 400, 400); y.add(f, BorderLayout.CENTER); y.setSize(450, 450); y.setVisible(true); y.setDefaultCloseOperation(y.EXIT_ON_CLOSE); f.genRand(); f.repaint(); } public void push(int[] xy) { coordinates.add(xy); int i = coordinates.size(); coordinates.ensureCapacity(i++); } public int[] pop() { int[] x = coordinates.get((coordinates.size())-1); coordinates.remove((coordinates.size())-1); return x; } public int[] top() { return coordinates.get((coordinates.size())-1); } public void genRand(){ // create a CellStack (LIFO) to hold a list of cell locations [x] // set TotalCells = number of cells in grid int TotalCells = size*size; // choose a cell at random and call it CurrentCell int m = randomInt(size); int n = randomInt(size); Cell curCel = maze[m][n]; // set VisitedCells = 1 int visCel = 1,d=0; int[] q; int h,o = 0,p = 0; // while VisitedCells < TotalCells while( visCel < TotalCells){ // find all neighbors of CurrentCell with all walls intact if(maze[m-1][n].countWalls() == 4){d++;} if(maze[m+1][n].countWalls() == 4){d++;} if(maze[m][n-1].countWalls() == 4){d++;} if(maze[m][n+1].countWalls() == 4){d++;} // if one or more found if(d!=0){ Point[] ls = new Point[4]; ls[0] = new Point(m-1,n); ls[1] = new Point(m+1,n); ls[2] = new Point(m,n-1); ls[3] = new Point(m,n+1); // knock down the wall between it and CurrentCell h = randomInt(3); switch(h){ case 0: o = (int)(ls[0].getX()); p = (int)(ls[0].getY()); curCel.destroyWall(2); maze[o][p].destroyWall(1); break; case 1: o = (int)(ls[1].getX()); p = (int)(ls[1].getY()); curCel.destroyWall(1); maze[o][p].destroyWall(2); break; case 2: o = (int)(ls[2].getX()); p = (int)(ls[2].getY()); curCel.destroyWall(3); maze[o][p].destroyWall(0); break; case 3: o = (int)(ls[3].getX()); p = (int)(ls[3].getY()); curCel.destroyWall(0); maze[o][p].destroyWall(3); break; } // push CurrentCell location on the CellStack push(new int[] {m,n}); // make the new cell CurrentCell m = o; n = p; curCel = maze[m][n]; // add 1 to VisitedCells visCel++; } // else else{ // pop the most recent cell entry off the CellStack q = pop(); m = q[0]; n = q[1]; curCel = maze[m][n]; // make it CurrentCell // endIf } // endWhile } } public int randomInt(int s) { return (int)(s* Math.random());} public void paint(Graphics g) { int k, j; width = getSize().width; height = getSize().height; double htOfRow = height / (size); double wdOfRow = width / (size); //checks verticals - destroys east border of cell for (k = 0; k < size; k++) { for (j = 0; j < size; j++) { if(maze[k][j].checkWall(2)){ g.drawLine((int) (k * wdOfRow), (int) (j * htOfRow), (int) (k * wdOfRow), (int) ((j+1) * htOfRow)); }} } //checks horizontal - destroys north border of cell for (k = 0; k < size; k++) { for (j = 0; j < size; j++) { if(maze[k][j].checkWall(3)){ g.drawLine((int) (k * wdOfRow), (int) (j * htOfRow), (int) ((k+1) * wdOfRow), (int) (j * htOfRow)); }} } } } class Cell { private final static int NORTH = 0; private final static int EAST = 1; private final static int WEST = 2; private final static int SOUTH = 3; private final static int NO = 4; private final static int START = 1; private final static int END = 2; boolean[] wall = new boolean[4]; boolean[] border = new boolean[4]; boolean[] backtrack = new boolean[4]; boolean[] solution = new boolean[4]; private boolean isVisited = false; private int Key = 0; public Cell(){ for(int i=0;i<4;i++){wall[i] = true;} } public int countWalls(){ int i, k =0; for(i=0; i<4; i++) { if (wall[i] == true) {k++;} } return k;} public boolean checkWall(int x){ switch(x){ case 0: return wall[0]; case 1: return wall[1]; case 2: return wall[2]; case 3: return wall[3]; } return true; } public void destroyWall(int x){ switch(x){ case 0: wall[0] = false; break; case 1: wall[1] = false; break; case 2: wall[2] = false; break; case 3: wall[3] = false; break; } } public void setStart(int i){Key = i;} public int getKey(){return Key;} public boolean checkVisit(){return isVisited;} public void visitCell(){isVisited = true;} }

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  • Having trouble binding a ksoap object to an ArrayList in Android

    - by Maskau
    I'm working on an app that calls a web service, then the webservice returns an array list. My problem is I am having trouble getting the data into the ArrayList and then displaying in a ListView. Any ideas what I am doing wrong? I know for a fact the web service returns an ArrayList. Everything seems to be working fine, just no data in the ListView or the ArrayList.....Thanks in advance! EDIT: So I added more code to the catch block of run() and now it's returning "org.ksoap2.serialization.SoapObject".....no more no less....and I am even more confused now... package com.maskau; import java.util.ArrayList; import org.ksoap2.SoapEnvelope; import org.ksoap2.serialization.PropertyInfo; import org.ksoap2.serialization.SoapObject; import org.ksoap2.serialization.SoapSerializationEnvelope; import org.ksoap2.transport.AndroidHttpTransport; import android.app.*; import android.os.*; import android.widget.ArrayAdapter; import android.widget.Button; import android.widget.EditText; import android.widget.ListView; import android.widget.TextView; import android.view.View; import android.view.View.OnClickListener; public class Home extends Activity implements Runnable{ /** Called when the activity is first created. */ public static final String SOAP_ACTION = "http://bb.mcrcog.com/GetArtist"; public static final String METHOD_NAME = "GetArtist"; public static final String NAMESPACE = "http://bb.mcrcog.com"; public static final String URL = "http://bb.mcrcog.com/karaoke/service.asmx"; String wt; public static ProgressDialog pd; TextView text1; ListView lv; static EditText myEditText; static Button but; private ArrayList<String> Artist_Result = new ArrayList<String>(); @Override public void onCreate(Bundle icicle) { super.onCreate(icicle); setContentView(R.layout.main); myEditText = (EditText)findViewById(R.id.myEditText); text1 = (TextView)findViewById(R.id.text1); lv = (ListView)findViewById(R.id.lv); but = (Button)findViewById(R.id.but); but.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { wt = ("Searching for " + myEditText.getText().toString()); text1.setText(""); pd = ProgressDialog.show(Home.this, "Working...", wt , true, false); Thread thread = new Thread(Home.this); thread.start(); } } ); } public void run() { try { SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME); PropertyInfo pi = new PropertyInfo(); pi.setName("ArtistQuery"); pi.setValue(Home.myEditText.getText().toString()); request.addProperty(pi); SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11); envelope.dotNet = true; envelope.setOutputSoapObject(request); AndroidHttpTransport at = new AndroidHttpTransport(URL); at.call(SOAP_ACTION, envelope); java.util.Vector<Object> rs = (java.util.Vector<Object>)envelope.getResponse(); if (rs != null) { for (Object cs : rs) { Artist_Result.add(cs.toString()); } } } catch (Exception e) { // Added this line, throws "org.ksoap2.serialization.SoapObject" when run Artist_Result.add(e.getMessage()); } handler.sendEmptyMessage(0); } private Handler handler = new Handler() { @Override public void handleMessage(Message msg) { ArrayAdapter<String> aa; aa = new ArrayAdapter<String>(Home.this, android.R.layout.simple_list_item_1, Artist_Result); lv.setAdapter(aa); try { if (Artist_Result.isEmpty()) { text1.setText("No Results"); } else { text1.setText("Complete"); myEditText.setText("Search Artist"); } } catch(Exception e) { text1.setText(e.getMessage()); } aa.notifyDataSetChanged(); pd.dismiss(); } }; }

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  • Searching for Windows User SID's in C#

    - by Ubiquitous Che
    Context Context first - issues I'm trying to resolve are below. One of our clients has asked as to quote how long it would take for us to improve one of our applications. This application currently provides basic user authentication in the form of username/password combinations. This client would like the ability for their employees to log-in using the details of whatever Windows User account is currently logged in at the time of running the application. It's not a deal-breaker if I tell them know - but the client might be willing to pay the costs of development to add this feature to the application. It's worth looking into. Based on my hunting around, it seems like storing the user login details against Domain\Username will be problematic if those details are changed. But Windows User SID's aren't supposed to change at all. I've got the impression that it would be best to record Windows Users by SID - feel free to relieve me of that if I'm wrong. I've been having a fiddle with some Windows API calls. From within C#, grabbing the current user's SID is easy enough. I can already take any user's SID and process it using LookupAccountSid to get username and domain for display purposes. For the interested, my code for this is at the end of this post. That's just the tip of the iceberg, however. The two issues below are completely outside my experience. Not only do I not know how to implement them - I don't even known how to find out how to implement them, or what the pitfalls are on various systems. Any help getting myself aimed in the right direction would be very much appreciated. Issue 1) Getting hold of the local user at runtime is meaningless if that user hasn't been granted access to the application. We will need to add a new section to our application's 'administrator console' for adding Windows Users (or groups) and assigning within-app permissions against those users. Something like an 'Add Windows User Login' button that will raise a pop-up window that will allow the user to search for available Windows User accounts on the network (not just the local machine) to be added to the list of available application logins. If there's already a component in .NET or Windows that I can shanghai into doing this for me, it would make me a very happy man. Issue 2) I also want to know how to take a given Windows User SID and check it against a given Windows User Group (probably taken from a database). I'm not sure how to get started with this one either, though I expect it to be easier than the issue above. For the Interested [STAThread] static void Main(string[] args) { MessageBox.Show(WindowsUserManager.GetAccountNameFromSID(WindowsIdentity.GetCurrent().User.Value)); MessageBox.Show(WindowsUserManager.GetAccountNameFromSID("S-1-5-21-57989841-842925246-1957994488-1003")); } public static class WindowsUserManager { public static string GetAccountNameFromSID(string SID) { try { StringBuilder name = new StringBuilder(); uint cchName = (uint)name.Capacity; StringBuilder referencedDomainName = new StringBuilder(); uint cchReferencedDomainName = (uint)referencedDomainName.Capacity; WindowsUserManager.SID_NAME_USE sidUse; int err = (int)ESystemError.ERROR_SUCCESS; if (!WindowsUserManager.LookupAccountSid(null, SID, name, ref cchName, referencedDomainName, ref cchReferencedDomainName, out sidUse)) { err = Marshal.GetLastWin32Error(); if (err == (int)ESystemError.ERROR_INSUFFICIENT_BUFFER) { name.EnsureCapacity((int)cchName); referencedDomainName.EnsureCapacity((int)cchReferencedDomainName); err = WindowsUserManager.LookupAccountSid(null, SID, name, ref cchName, referencedDomainName, ref cchReferencedDomainName, out sidUse) ? (int)ESystemError.ERROR_SUCCESS : Marshal.GetLastWin32Error(); } } if (err != (int)ESystemError.ERROR_SUCCESS) throw new ApplicationException(String.Format("Could not retrieve acount name from SID. {0}", SystemExceptionManager.GetDescription(err))); return String.Format(@"{0}\{1}", referencedDomainName.ToString(), name.ToString()); } catch (Exception ex) { if (ex is ApplicationException) throw ex; throw new ApplicationException("Could not retrieve acount name from SID", ex); } } private enum SID_NAME_USE { SidTypeUser = 1, SidTypeGroup, SidTypeDomain, SidTypeAlias, SidTypeWellKnownGroup, SidTypeDeletedAccount, SidTypeInvalid, SidTypeUnknown, SidTypeComputer } [DllImport("advapi32.dll", EntryPoint = "GetLengthSid", CharSet = CharSet.Auto)] private static extern int GetLengthSid(IntPtr pSID); [DllImport("advapi32.dll", SetLastError = true)] private static extern bool ConvertStringSidToSid( string StringSid, out IntPtr ptrSid); [DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)] private static extern bool LookupAccountSid( string lpSystemName, [MarshalAs(UnmanagedType.LPArray)] byte[] Sid, StringBuilder lpName, ref uint cchName, StringBuilder ReferencedDomainName, ref uint cchReferencedDomainName, out SID_NAME_USE peUse); private static bool LookupAccountSid( string lpSystemName, string stringSid, StringBuilder lpName, ref uint cchName, StringBuilder ReferencedDomainName, ref uint cchReferencedDomainName, out SID_NAME_USE peUse) { byte[] SID = null; IntPtr SID_ptr = IntPtr.Zero; try { WindowsUserManager.ConvertStringSidToSid(stringSid, out SID_ptr); int err = SID_ptr == IntPtr.Zero ? Marshal.GetLastWin32Error() : (int)ESystemError.ERROR_SUCCESS; if (SID_ptr == IntPtr.Zero || err != (int)ESystemError.ERROR_SUCCESS) throw new ApplicationException(String.Format("'{0}' could not be converted to a SID byte array. {1}", stringSid, SystemExceptionManager.GetDescription(err))); int size = (int)GetLengthSid(SID_ptr); SID = new byte[size]; Marshal.Copy(SID_ptr, SID, 0, size); } catch (Exception ex) { if (ex is ApplicationException) throw ex; throw new ApplicationException(String.Format("'{0}' could not be converted to a SID byte array. {1}.", stringSid, ex.Message), ex); } finally { // Always want to release the SID_ptr (if it exists) to avoid memory leaks. if (SID_ptr != IntPtr.Zero) Marshal.FreeHGlobal(SID_ptr); } return WindowsUserManager.LookupAccountSid(lpSystemName, SID, lpName, ref cchName, ReferencedDomainName, ref cchReferencedDomainName, out peUse); } }

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  • std::basic_stringstream<unsigned char> won't compile with MSVC 10

    - by Michael J
    I'm trying to get UTF-8 chars to co-exist with ANSI 8-bit chars. My strategy has been to represent utf-8 chars as unsigned char so that appropriate overloads of functions can be used for the two character types. e.g. namespace MyStuff { typedef uchar utf8_t; typedef std::basic_string<utf8_t> U8string; } void SomeFunc(std::string &s); void SomeFunc(std::wstring &s); void SomeFunc(MyStuff::U8string &s); This all works pretty well until I try to use a stringstream. std::basic_ostringstream<MyStuff::utf8_t> ostr; ostr << 1; MSVC Visual C++ Express V10 won't compile this: c:\program files\microsoft visual studio 10.0\vc\include\xlocmon(213): warning C4273: 'id' : inconsistent dll linkage c:\program files\microsoft visual studio 10.0\vc\include\xlocnum(65) : see previous definition of 'public: static std::locale::id std::numpunct<unsigned char>::id' c:\program files\microsoft visual studio 10.0\vc\include\xlocnum(65) : while compiling class template static data member 'std::locale::id std::numpunct<_Elem>::id' with [ _Elem=Tk::utf8_t ] c:\program files\microsoft visual studio 10.0\vc\include\xlocnum(1149) : see reference to function template instantiation 'const _Facet &std::use_facet<std::numpunct<_Elem>>(const std::locale &)' being compiled with [ _Facet=std::numpunct<Tk::utf8_t>, _Elem=Tk::utf8_t ] c:\program files\microsoft visual studio 10.0\vc\include\xlocnum(1143) : while compiling class template member function 'std::ostreambuf_iterator<_Elem,_Traits> std::num_put<_Elem,_OutIt>:: do_put(_OutIt,std::ios_base &,_Elem,std::_Bool) const' with [ _Elem=Tk::utf8_t, _Traits=std::char_traits<Tk::utf8_t>, _OutIt=std::ostreambuf_iterator<Tk::utf8_t,std::char_traits<Tk::utf8_t>> ] c:\program files\microsoft visual studio 10.0\vc\include\ostream(295) : see reference to class template instantiation 'std::num_put<_Elem,_OutIt>' being compiled with [ _Elem=Tk::utf8_t, _OutIt=std::ostreambuf_iterator<Tk::utf8_t,std::char_traits<Tk::utf8_t>> ] c:\program files\microsoft visual studio 10.0\vc\include\ostream(281) : while compiling class template member function 'std::basic_ostream<_Elem,_Traits> & std::basic_ostream<_Elem,_Traits>::operator <<(int)' with [ _Elem=Tk::utf8_t, _Traits=std::char_traits<Tk::utf8_t> ] c:\program files\microsoft visual studio 10.0\vc\include\sstream(526) : see reference to class template instantiation 'std::basic_ostream<_Elem,_Traits>' being compiled with [ _Elem=Tk::utf8_t, _Traits=std::char_traits<Tk::utf8_t> ] c:\users\michael\dvl\tmp\console\console.cpp(23) : see reference to class template instantiation 'std::basic_ostringstream<_Elem,_Traits,_Alloc>' being compiled with [ _Elem=Tk::utf8_t, _Traits=std::char_traits<Tk::utf8_t>, _Alloc=std::allocator<uchar> ] . c:\program files\microsoft visual studio 10.0\vc\include\xlocmon(213): error C2491: 'std::numpunct<_Elem>::id' : definition of dllimport static data member not allowed with [ _Elem=Tk::utf8_t ] Any ideas? ** Edited 19 June 2012 ** OK, I've gotten closer to understanding this, but not how to solve it. As we all know, static class variables get defined twice: once in the class definition and once outside the class definition which establishes storage space. e.g. // in .h file class CFoo { // ... static int x; }; // in .cpp file int CFoo::x = 42; Now in the VC10 headers we get something like this: template<class _Elem> class numpunct : public locale::facet { // ... _CRTIMP2_PURE static locale::id id; // ... } When the header is included in an application, _CRTIMP2_PURE is defined as __declspec(dllimport), which means that the variable is imported from a dll. Now the header also contains the following template<class _Elem> locale::id numpunct<_Elem>::id; Note the absence of the __declspec(dllimport) qualifier. i.e. The class declaration says that the static linkage of the id variable is in the dll, but for the general case, it gets declared outside the dll. For the known cases, there are specialisations. template locale::id numpunct<char>::id; template locale::id numpunct<wchar_t>::id; These are protected by #ifs so that they are only included when building the DLL. They are excluded otherwise. i.e. the char and wchar_t versions of numpunct ARE inside the dll So we have the class definition saying that id's storage is in the DLL, but that is only true for the char and wchar_t specialisations, meaning that my unsigned char version is doomed. :-( The only way forward that I can think of is to create my own specialisation: basically copying it from the header file and fixing it. This raises many issues. Anybody have a better idea?

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  • value types in the vm

    - by john.rose
    value types in the vm p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} p.p2 {margin: 0.0px 0.0px 14.0px 0.0px; font: 14.0px Times} p.p3 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times} p.p4 {margin: 0.0px 0.0px 15.0px 0.0px; font: 14.0px Times} p.p5 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier} p.p6 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier; min-height: 17.0px} p.p7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p8 {margin: 0.0px 0.0px 0.0px 36.0px; text-indent: -36.0px; font: 14.0px Times; min-height: 18.0px} p.p9 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p10 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; color: #000000} li.li1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} li.li7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} span.s1 {font: 14.0px Courier} span.s2 {color: #000000} span.s3 {font: 14.0px Courier; color: #000000} ol.ol1 {list-style-type: decimal} Or, enduring values for a changing world. Introduction A value type is a data type which, generally speaking, is designed for being passed by value in and out of methods, and stored by value in data structures. The only value types which the Java language directly supports are the eight primitive types. Java indirectly and approximately supports value types, if they are implemented in terms of classes. For example, both Integer and String may be viewed as value types, especially if their usage is restricted to avoid operations appropriate to Object. In this note, we propose a definition of value types in terms of a design pattern for Java classes, accompanied by a set of usage restrictions. We also sketch the relation of such value types to tuple types (which are a JVM-level notion), and point out JVM optimizations that can apply to value types. This note is a thought experiment to extend the JVM’s performance model in support of value types. The demonstration has two phases.  Initially the extension can simply use design patterns, within the current bytecode architecture, and in today’s Java language. But if the performance model is to be realized in practice, it will probably require new JVM bytecode features, changes to the Java language, or both.  We will look at a few possibilities for these new features. An Axiom of Value In the context of the JVM, a value type is a data type equipped with construction, assignment, and equality operations, and a set of typed components, such that, whenever two variables of the value type produce equal corresponding values for their components, the values of the two variables cannot be distinguished by any JVM operation. Here are some corollaries: A value type is immutable, since otherwise a copy could be constructed and the original could be modified in one of its components, allowing the copies to be distinguished. Changing the component of a value type requires construction of a new value. The equals and hashCode operations are strictly component-wise. If a value type is represented by a JVM reference, that reference cannot be successfully synchronized on, and cannot be usefully compared for reference equality. A value type can be viewed in terms of what it doesn’t do. We can say that a value type omits all value-unsafe operations, which could violate the constraints on value types.  These operations, which are ordinarily allowed for Java object types, are pointer equality comparison (the acmp instruction), synchronization (the monitor instructions), all the wait and notify methods of class Object, and non-trivial finalize methods. The clone method is also value-unsafe, although for value types it could be treated as the identity function. Finally, and most importantly, any side effect on an object (however visible) also counts as an value-unsafe operation. A value type may have methods, but such methods must not change the components of the value. It is reasonable and useful to define methods like toString, equals, and hashCode on value types, and also methods which are specifically valuable to users of the value type. Representations of Value Value types have two natural representations in the JVM, unboxed and boxed. An unboxed value consists of the components, as simple variables. For example, the complex number x=(1+2i), in rectangular coordinate form, may be represented in unboxed form by the following pair of variables: /*Complex x = Complex.valueOf(1.0, 2.0):*/ double x_re = 1.0, x_im = 2.0; These variables might be locals, parameters, or fields. Their association as components of a single value is not defined to the JVM. Here is a sample computation which computes the norm of the difference between two complex numbers: double distance(/*Complex x:*/ double x_re, double x_im,         /*Complex y:*/ double y_re, double y_im) {     /*Complex z = x.minus(y):*/     double z_re = x_re - y_re, z_im = x_im - y_im;     /*return z.abs():*/     return Math.sqrt(z_re*z_re + z_im*z_im); } A boxed representation groups component values under a single object reference. The reference is to a ‘wrapper class’ that carries the component values in its fields. (A primitive type can naturally be equated with a trivial value type with just one component of that type. In that view, the wrapper class Integer can serve as a boxed representation of value type int.) The unboxed representation of complex numbers is practical for many uses, but it fails to cover several major use cases: return values, array elements, and generic APIs. The two components of a complex number cannot be directly returned from a Java function, since Java does not support multiple return values. The same story applies to array elements: Java has no ’array of structs’ feature. (Double-length arrays are a possible workaround for complex numbers, but not for value types with heterogeneous components.) By generic APIs I mean both those which use generic types, like Arrays.asList and those which have special case support for primitive types, like String.valueOf and PrintStream.println. Those APIs do not support unboxed values, and offer some problems to boxed values. Any ’real’ JVM type should have a story for returns, arrays, and API interoperability. The basic problem here is that value types fall between primitive types and object types. Value types are clearly more complex than primitive types, and object types are slightly too complicated. Objects are a little bit dangerous to use as value carriers, since object references can be compared for pointer equality, and can be synchronized on. Also, as many Java programmers have observed, there is often a performance cost to using wrapper objects, even on modern JVMs. Even so, wrapper classes are a good starting point for talking about value types. If there were a set of structural rules and restrictions which would prevent value-unsafe operations on value types, wrapper classes would provide a good notation for defining value types. This note attempts to define such rules and restrictions. Let’s Start Coding Now it is time to look at some real code. Here is a definition, written in Java, of a complex number value type. @ValueSafe public final class Complex implements java.io.Serializable {     // immutable component structure:     public final double re, im;     private Complex(double re, double im) {         this.re = re; this.im = im;     }     // interoperability methods:     public String toString() { return "Complex("+re+","+im+")"; }     public List<Double> asList() { return Arrays.asList(re, im); }     public boolean equals(Complex c) {         return re == c.re && im == c.im;     }     public boolean equals(@ValueSafe Object x) {         return x instanceof Complex && equals((Complex) x);     }     public int hashCode() {         return 31*Double.valueOf(re).hashCode()                 + Double.valueOf(im).hashCode();     }     // factory methods:     public static Complex valueOf(double re, double im) {         return new Complex(re, im);     }     public Complex changeRe(double re2) { return valueOf(re2, im); }     public Complex changeIm(double im2) { return valueOf(re, im2); }     public static Complex cast(@ValueSafe Object x) {         return x == null ? ZERO : (Complex) x;     }     // utility methods and constants:     public Complex plus(Complex c)  { return new Complex(re+c.re, im+c.im); }     public Complex minus(Complex c) { return new Complex(re-c.re, im-c.im); }     public double abs() { return Math.sqrt(re*re + im*im); }     public static final Complex PI = valueOf(Math.PI, 0.0);     public static final Complex ZERO = valueOf(0.0, 0.0); } This is not a minimal definition, because it includes some utility methods and other optional parts.  The essential elements are as follows: The class is marked as a value type with an annotation. The class is final, because it does not make sense to create subclasses of value types. The fields of the class are all non-private and final.  (I.e., the type is immutable and structurally transparent.) From the supertype Object, all public non-final methods are overridden. The constructor is private. Beyond these bare essentials, we can observe the following features in this example, which are likely to be typical of all value types: One or more factory methods are responsible for value creation, including a component-wise valueOf method. There are utility methods for complex arithmetic and instance creation, such as plus and changeIm. There are static utility constants, such as PI. The type is serializable, using the default mechanisms. There are methods for converting to and from dynamically typed references, such as asList and cast. The Rules In order to use value types properly, the programmer must avoid value-unsafe operations.  A helpful Java compiler should issue errors (or at least warnings) for code which provably applies value-unsafe operations, and should issue warnings for code which might be correct but does not provably avoid value-unsafe operations.  No such compilers exist today, but to simplify our account here, we will pretend that they do exist. A value-safe type is any class, interface, or type parameter marked with the @ValueSafe annotation, or any subtype of a value-safe type.  If a value-safe class is marked final, it is in fact a value type.  All other value-safe classes must be abstract.  The non-static fields of a value class must be non-public and final, and all its constructors must be private. Under the above rules, a standard interface could be helpful to define value types like Complex.  Here is an example: @ValueSafe public interface ValueType extends java.io.Serializable {     // All methods listed here must get redefined.     // Definitions must be value-safe, which means     // they may depend on component values only.     List<? extends Object> asList();     int hashCode();     boolean equals(@ValueSafe Object c);     String toString(); } //@ValueSafe inherited from supertype: public final class Complex implements ValueType { … The main advantage of such a conventional interface is that (unlike an annotation) it is reified in the runtime type system.  It could appear as an element type or parameter bound, for facilities which are designed to work on value types only.  More broadly, it might assist the JVM to perform dynamic enforcement of the rules for value types. Besides types, the annotation @ValueSafe can mark fields, parameters, local variables, and methods.  (This is redundant when the type is also value-safe, but may be useful when the type is Object or another supertype of a value type.)  Working forward from these annotations, an expression E is defined as value-safe if it satisfies one or more of the following: The type of E is a value-safe type. E names a field, parameter, or local variable whose declaration is marked @ValueSafe. E is a call to a method whose declaration is marked @ValueSafe. E is an assignment to a value-safe variable, field reference, or array reference. E is a cast to a value-safe type from a value-safe expression. E is a conditional expression E0 ? E1 : E2, and both E1 and E2 are value-safe. Assignments to value-safe expressions and initializations of value-safe names must take their values from value-safe expressions. A value-safe expression may not be the subject of a value-unsafe operation.  In particular, it cannot be synchronized on, nor can it be compared with the “==” operator, not even with a null or with another value-safe type. In a program where all of these rules are followed, no value-type value will be subject to a value-unsafe operation.  Thus, the prime axiom of value types will be satisfied, that no two value type will be distinguishable as long as their component values are equal. More Code To illustrate these rules, here are some usage examples for Complex: Complex pi = Complex.valueOf(Math.PI, 0); Complex zero = pi.changeRe(0);  //zero = pi; zero.re = 0; ValueType vtype = pi; @SuppressWarnings("value-unsafe")   Object obj = pi; @ValueSafe Object obj2 = pi; obj2 = new Object();  // ok List<Complex> clist = new ArrayList<Complex>(); clist.add(pi);  // (ok assuming List.add param is @ValueSafe) List<ValueType> vlist = new ArrayList<ValueType>(); vlist.add(pi);  // (ok) List<Object> olist = new ArrayList<Object>(); olist.add(pi);  // warning: "value-unsafe" boolean z = pi.equals(zero); boolean z1 = (pi == zero);  // error: reference comparison on value type boolean z2 = (pi == null);  // error: reference comparison on value type boolean z3 = (pi == obj2);  // error: reference comparison on value type synchronized (pi) { }  // error: synch of value, unpredictable result synchronized (obj2) { }  // unpredictable result Complex qq = pi; qq = null;  // possible NPE; warning: “null-unsafe" qq = (Complex) obj;  // warning: “null-unsafe" qq = Complex.cast(obj);  // OK @SuppressWarnings("null-unsafe")   Complex empty = null;  // possible NPE qq = empty;  // possible NPE (null pollution) The Payoffs It follows from this that either the JVM or the java compiler can replace boxed value-type values with unboxed ones, without affecting normal computations.  Fields and variables of value types can be split into their unboxed components.  Non-static methods on value types can be transformed into static methods which take the components as value parameters. Some common questions arise around this point in any discussion of value types. Why burden the programmer with all these extra rules?  Why not detect programs automagically and perform unboxing transparently?  The answer is that it is easy to break the rules accidently unless they are agreed to by the programmer and enforced.  Automatic unboxing optimizations are tantalizing but (so far) unreachable ideal.  In the current state of the art, it is possible exhibit benchmarks in which automatic unboxing provides the desired effects, but it is not possible to provide a JVM with a performance model that assures the programmer when unboxing will occur.  This is why I’m writing this note, to enlist help from, and provide assurances to, the programmer.  Basically, I’m shooting for a good set of user-supplied “pragmas” to frame the desired optimization. Again, the important thing is that the unboxing must be done reliably, or else programmers will have no reason to work with the extra complexity of the value-safety rules.  There must be a reasonably stable performance model, wherein using a value type has approximately the same performance characteristics as writing the unboxed components as separate Java variables. There are some rough corners to the present scheme.  Since Java fields and array elements are initialized to null, value-type computations which incorporate uninitialized variables can produce null pointer exceptions.  One workaround for this is to require such variables to be null-tested, and the result replaced with a suitable all-zero value of the value type.  That is what the “cast” method does above. Generically typed APIs like List<T> will continue to manipulate boxed values always, at least until we figure out how to do reification of generic type instances.  Use of such APIs will elicit warnings until their type parameters (and/or relevant members) are annotated or typed as value-safe.  Retrofitting List<T> is likely to expose flaws in the present scheme, which we will need to engineer around.  Here are a couple of first approaches: public interface java.util.List<@ValueSafe T> extends Collection<T> { … public interface java.util.List<T extends Object|ValueType> extends Collection<T> { … (The second approach would require disjunctive types, in which value-safety is “contagious” from the constituent types.) With more transformations, the return value types of methods can also be unboxed.  This may require significant bytecode-level transformations, and would work best in the presence of a bytecode representation for multiple value groups, which I have proposed elsewhere under the title “Tuples in the VM”. But for starters, the JVM can apply this transformation under the covers, to internally compiled methods.  This would give a way to express multiple return values and structured return values, which is a significant pain-point for Java programmers, especially those who work with low-level structure types favored by modern vector and graphics processors.  The lack of multiple return values has a strong distorting effect on many Java APIs. Even if the JVM fails to unbox a value, there is still potential benefit to the value type.  Clustered computing systems something have copy operations (serialization or something similar) which apply implicitly to command operands.  When copying JVM objects, it is extremely helpful to know when an object’s identity is important or not.  If an object reference is a copied operand, the system may have to create a proxy handle which points back to the original object, so that side effects are visible.  Proxies must be managed carefully, and this can be expensive.  On the other hand, value types are exactly those types which a JVM can “copy and forget” with no downside. Array types are crucial to bulk data interfaces.  (As data sizes and rates increase, bulk data becomes more important than scalar data, so arrays are definitely accompanying us into the future of computing.)  Value types are very helpful for adding structure to bulk data, so a successful value type mechanism will make it easier for us to express richer forms of bulk data. Unboxing arrays (i.e., arrays containing unboxed values) will provide better cache and memory density, and more direct data movement within clustered or heterogeneous computing systems.  They require the deepest transformations, relative to today’s JVM.  There is an impedance mismatch between value-type arrays and Java’s covariant array typing, so compromises will need to be struck with existing Java semantics.  It is probably worth the effort, since arrays of unboxed value types are inherently more memory-efficient than standard Java arrays, which rely on dependent pointer chains. It may be sufficient to extend the “value-safe” concept to array declarations, and allow low-level transformations to change value-safe array declarations from the standard boxed form into an unboxed tuple-based form.  Such value-safe arrays would not be convertible to Object[] arrays.  Certain connection points, such as Arrays.copyOf and System.arraycopy might need additional input/output combinations, to allow smooth conversion between arrays with boxed and unboxed elements. Alternatively, the correct solution may have to wait until we have enough reification of generic types, and enough operator overloading, to enable an overhaul of Java arrays. Implicit Method Definitions The example of class Complex above may be unattractively complex.  I believe most or all of the elements of the example class are required by the logic of value types. If this is true, a programmer who writes a value type will have to write lots of error-prone boilerplate code.  On the other hand, I think nearly all of the code (except for the domain-specific parts like plus and minus) can be implicitly generated. Java has a rule for implicitly defining a class’s constructor, if no it defines no constructors explicitly.  Likewise, there are rules for providing default access modifiers for interface members.  Because of the highly regular structure of value types, it might be reasonable to perform similar implicit transformations on value types.  Here’s an example of a “highly implicit” definition of a complex number type: public class Complex implements ValueType {  // implicitly final     public double re, im;  // implicitly public final     //implicit methods are defined elementwise from te fields:     //  toString, asList, equals(2), hashCode, valueOf, cast     //optionally, explicit methods (plus, abs, etc.) would go here } In other words, with the right defaults, a simple value type definition can be a one-liner.  The observant reader will have noticed the similarities (and suitable differences) between the explicit methods above and the corresponding methods for List<T>. Another way to abbreviate such a class would be to make an annotation the primary trigger of the functionality, and to add the interface(s) implicitly: public @ValueType class Complex { … // implicitly final, implements ValueType (But to me it seems better to communicate the “magic” via an interface, even if it is rooted in an annotation.) Implicitly Defined Value Types So far we have been working with nominal value types, which is to say that the sequence of typed components is associated with a name and additional methods that convey the intention of the programmer.  A simple ordered pair of floating point numbers can be variously interpreted as (to name a few possibilities) a rectangular or polar complex number or Cartesian point.  The name and the methods convey the intended meaning. But what if we need a truly simple ordered pair of floating point numbers, without any further conceptual baggage?  Perhaps we are writing a method (like “divideAndRemainder”) which naturally returns a pair of numbers instead of a single number.  Wrapping the pair of numbers in a nominal type (like “QuotientAndRemainder”) makes as little sense as wrapping a single return value in a nominal type (like “Quotient”).  What we need here are structural value types commonly known as tuples. For the present discussion, let us assign a conventional, JVM-friendly name to tuples, roughly as follows: public class java.lang.tuple.$DD extends java.lang.tuple.Tuple {      double $1, $2; } Here the component names are fixed and all the required methods are defined implicitly.  The supertype is an abstract class which has suitable shared declarations.  The name itself mentions a JVM-style method parameter descriptor, which may be “cracked” to determine the number and types of the component fields. The odd thing about such a tuple type (and structural types in general) is it must be instantiated lazily, in response to linkage requests from one or more classes that need it.  The JVM and/or its class loaders must be prepared to spin a tuple type on demand, given a simple name reference, $xyz, where the xyz is cracked into a series of component types.  (Specifics of naming and name mangling need some tasteful engineering.) Tuples also seem to demand, even more than nominal types, some support from the language.  (This is probably because notations for non-nominal types work best as combinations of punctuation and type names, rather than named constructors like Function3 or Tuple2.)  At a minimum, languages with tuples usually (I think) have some sort of simple bracket notation for creating tuples, and a corresponding pattern-matching syntax (or “destructuring bind”) for taking tuples apart, at least when they are parameter lists.  Designing such a syntax is no simple thing, because it ought to play well with nominal value types, and also with pre-existing Java features, such as method parameter lists, implicit conversions, generic types, and reflection.  That is a task for another day. Other Use Cases Besides complex numbers and simple tuples there are many use cases for value types.  Many tuple-like types have natural value-type representations. These include rational numbers, point locations and pixel colors, and various kinds of dates and addresses. Other types have a variable-length ‘tail’ of internal values. The most common example of this is String, which is (mathematically) a sequence of UTF-16 character values. Similarly, bit vectors, multiple-precision numbers, and polynomials are composed of sequences of values. Such types include, in their representation, a reference to a variable-sized data structure (often an array) which (somehow) represents the sequence of values. The value type may also include ’header’ information. Variable-sized values often have a length distribution which favors short lengths. In that case, the design of the value type can make the first few values in the sequence be direct ’header’ fields of the value type. In the common case where the header is enough to represent the whole value, the tail can be a shared null value, or even just a null reference. Note that the tail need not be an immutable object, as long as the header type encapsulates it well enough. This is the case with String, where the tail is a mutable (but never mutated) character array. Field types and their order must be a globally visible part of the API.  The structure of the value type must be transparent enough to have a globally consistent unboxed representation, so that all callers and callees agree about the type and order of components  that appear as parameters, return types, and array elements.  This is a trade-off between efficiency and encapsulation, which is forced on us when we remove an indirection enjoyed by boxed representations.  A JVM-only transformation would not care about such visibility, but a bytecode transformation would need to take care that (say) the components of complex numbers would not get swapped after a redefinition of Complex and a partial recompile.  Perhaps constant pool references to value types need to declare the field order as assumed by each API user. This brings up the delicate status of private fields in a value type.  It must always be possible to load, store, and copy value types as coordinated groups, and the JVM performs those movements by moving individual scalar values between locals and stack.  If a component field is not public, what is to prevent hostile code from plucking it out of the tuple using a rogue aload or astore instruction?  Nothing but the verifier, so we may need to give it more smarts, so that it treats value types as inseparable groups of stack slots or locals (something like long or double). My initial thought was to make the fields always public, which would make the security problem moot.  But public is not always the right answer; consider the case of String, where the underlying mutable character array must be encapsulated to prevent security holes.  I believe we can win back both sides of the tradeoff, by training the verifier never to split up the components in an unboxed value.  Just as the verifier encapsulates the two halves of a 64-bit primitive, it can encapsulate the the header and body of an unboxed String, so that no code other than that of class String itself can take apart the values. Similar to String, we could build an efficient multi-precision decimal type along these lines: public final class DecimalValue extends ValueType {     protected final long header;     protected private final BigInteger digits;     public DecimalValue valueOf(int value, int scale) {         assert(scale >= 0);         return new DecimalValue(((long)value << 32) + scale, null);     }     public DecimalValue valueOf(long value, int scale) {         if (value == (int) value)             return valueOf((int)value, scale);         return new DecimalValue(-scale, new BigInteger(value));     } } Values of this type would be passed between methods as two machine words. Small values (those with a significand which fits into 32 bits) would be represented without any heap data at all, unless the DecimalValue itself were boxed. (Note the tension between encapsulation and unboxing in this case.  It would be better if the header and digits fields were private, but depending on where the unboxing information must “leak”, it is probably safer to make a public revelation of the internal structure.) Note that, although an array of Complex can be faked with a double-length array of double, there is no easy way to fake an array of unboxed DecimalValues.  (Either an array of boxed values or a transposed pair of homogeneous arrays would be reasonable fallbacks, in a current JVM.)  Getting the full benefit of unboxing and arrays will require some new JVM magic. Although the JVM emphasizes portability, system dependent code will benefit from using machine-level types larger than 64 bits.  For example, the back end of a linear algebra package might benefit from value types like Float4 which map to stock vector types.  This is probably only worthwhile if the unboxing arrays can be packed with such values. More Daydreams A more finely-divided design for dynamic enforcement of value safety could feature separate marker interfaces for each invariant.  An empty marker interface Unsynchronizable could cause suitable exceptions for monitor instructions on objects in marked classes.  More radically, a Interchangeable marker interface could cause JVM primitives that are sensitive to object identity to raise exceptions; the strangest result would be that the acmp instruction would have to be specified as raising an exception. @ValueSafe public interface ValueType extends java.io.Serializable,         Unsynchronizable, Interchangeable { … public class Complex implements ValueType {     // inherits Serializable, Unsynchronizable, Interchangeable, @ValueSafe     … It seems possible that Integer and the other wrapper types could be retro-fitted as value-safe types.  This is a major change, since wrapper objects would be unsynchronizable and their references interchangeable.  It is likely that code which violates value-safety for wrapper types exists but is uncommon.  It is less plausible to retro-fit String, since the prominent operation String.intern is often used with value-unsafe code. We should also reconsider the distinction between boxed and unboxed values in code.  The design presented above obscures that distinction.  As another thought experiment, we could imagine making a first class distinction in the type system between boxed and unboxed representations.  Since only primitive types are named with a lower-case initial letter, we could define that the capitalized version of a value type name always refers to the boxed representation, while the initial lower-case variant always refers to boxed.  For example: complex pi = complex.valueOf(Math.PI, 0); Complex boxPi = pi;  // convert to boxed myList.add(boxPi); complex z = myList.get(0);  // unbox Such a convention could perhaps absorb the current difference between int and Integer, double and Double. It might also allow the programmer to express a helpful distinction among array types. As said above, array types are crucial to bulk data interfaces, but are limited in the JVM.  Extending arrays beyond the present limitations is worth thinking about; for example, the Maxine JVM implementation has a hybrid object/array type.  Something like this which can also accommodate value type components seems worthwhile.  On the other hand, does it make sense for value types to contain short arrays?  And why should random-access arrays be the end of our design process, when bulk data is often sequentially accessed, and it might make sense to have heterogeneous streams of data as the natural “jumbo” data structure.  These considerations must wait for another day and another note. More Work It seems to me that a good sequence for introducing such value types would be as follows: Add the value-safety restrictions to an experimental version of javac. Code some sample applications with value types, including Complex and DecimalValue. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. A staggered roll-out like this would decouple language changes from bytecode changes, which is always a convenient thing. A similar investigation should be applied (concurrently) to array types.  In this case, it seems to me that the starting point is in the JVM: Add an experimental unboxing array data structure to a production JVM, perhaps along the lines of Maxine hybrids.  No bytecode or language support is required at first; everything can be done with encapsulated unsafe operations and/or method handles. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. That’s enough musing me for now.  Back to work!

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  • Injection with google guice does not work anymore after obfuscation with proguard

    - by sme
    Has anyone ever tried to combine the use of google guice with obfuscation (in particular proguard)? The obfuscated version of my code does not work with google guice as guice complains about missing type parameters. This information seems to be erased by the transformation step that proguard does, even when the relevant classes are excluded from the obfuscation. The stack trace looks like this: com.google.inject.CreationException: Guice creation errors: 1) Cannot inject a Provider that has no type parameter while locating com.google.inject.Provider for parameter 0 at de.repower.lvs.client.admin.user.administration.AdminUserCommonPanel.setPasswordPanelProvider(SourceFile:499) at de.repower.lvs.client.admin.user.administration.AdminUserCommonPanel.setPasswordPanelProvider(SourceFile:499) while locating de.repower.lvs.client.admin.user.administration.AdminUserCommonPanel for parameter 0 at de.repower.lvs.client.admin.user.administration.b.k.setParentPanel(SourceFile:65) at de.repower.lvs.client.admin.user.administration.b.k.setParentPanel(SourceFile:65) at de.repower.lvs.client.admin.user.administration.o.a(SourceFile:38) 2) Cannot inject a Provider that has no type parameter while locating com.google.inject.Provider for parameter 0 at de.repower.lvs.client.admin.user.administration.AdminUserCommonPanel.setWindTurbineAccessGroupProvider(SourceFile:509) at de.repower.lvs.client.admin.user.administration.AdminUserCommonPanel.setWindTurbineAccessGroupProvider(SourceFile:509) while locating de.repower.lvs.client.admin.user.administration.AdminUserCommonPanel for parameter 0 at de.repower.lvs.client.admin.user.administration.b.k.setParentPanel(SourceFile:65) at de.repower.lvs.client.admin.user.administration.b.k.setParentPanel(SourceFile:65) at de.repower.lvs.client.admin.user.administration.o.a(SourceFile:38) 2 errors at com.google.inject.internal.Errors.throwCreationExceptionIfErrorsExist(Errors.java:354) at com.google.inject.InjectorBuilder.initializeStatically(InjectorBuilder.java:152) at com.google.inject.InjectorBuilder.build(InjectorBuilder.java:105) at com.google.inject.Guice.createInjector(Guice.java:92) at com.google.inject.Guice.createInjector(Guice.java:69) at com.google.inject.Guice.createInjector(Guice.java:59) I tried to create a small example (without using guice) that seems to reproduce the problem: package de.repower.common; import java.lang.reflect.Method; import java.lang.reflect.ParameterizedType; import java.lang.reflect.Type; class SomeClass<S> { } public class ParameterizedTypeTest { public void someMethod(SomeClass<Integer> param) { System.out.println("value: " + param); System.setProperty("my.dummmy.property", "hallo"); } private static void checkParameterizedMethod(ParameterizedTypeTest testObject) { System.out.println("checking parameterized method ..."); Method[] methods = testObject.getClass().getMethods(); for (Method method : methods) { if (method.getName().equals("someMethod")) { System.out.println("Found method " + method.getName()); Type[] types = method.getGenericParameterTypes(); Type parameterType = types[0]; if (parameterType instanceof ParameterizedType) { Type parameterizedType = ((ParameterizedType) parameterType).getActualTypeArguments()[0]; System.out.println("Parameter: " + parameterizedType); System.out.println("Class: " + ((Class) parameterizedType).getName()); } else { System.out.println("Failed: type ist not instance of ParameterizedType"); } } } } public static void main(String[] args) { System.out.println("Starting ..."); try { ParameterizedTypeTest someInstance = new ParameterizedTypeTest(); checkParameterizedMethod(someInstance); } catch (SecurityException e) { e.printStackTrace(); } } } If you run this code unsbfuscated, the output looks like this: Starting ... checking parameterized method ... Found method someMethod Parameter: class java.lang.Integer Class: java.lang.Integer But running the version obfuscated with proguard yields: Starting ... checking parameterized method ... Found method someMethod Failed: type ist not instance of ParameterizedType These are the options I used for obfuscation: -injars classes_eclipse\methodTest.jar -outjars classes_eclipse\methodTestObfuscated.jar -libraryjars 'C:\Program Files\Java\jre6\lib\rt.jar' -dontskipnonpubliclibraryclasses -dontskipnonpubliclibraryclassmembers -dontshrink -printusage classes_eclipse\shrink.txt -dontoptimize -dontpreverify -verbose -keep class **.ParameterizedTypeTest.class { <fields>; <methods>; } -keep class ** { <fields>; <methods>; } # Keep - Applications. Keep all application classes, along with their 'main' # methods. -keepclasseswithmembers public class * { public static void main(java.lang.String[]); } # Also keep - Enumerations. Keep the special static methods that are required in # enumeration classes. -keepclassmembers enum * { public static **[] values(); public static ** valueOf(java.lang.String); } # Also keep - Database drivers. Keep all implementations of java.sql.Driver. -keep class * extends java.sql.Driver # Also keep - Swing UI L&F. Keep all extensions of javax.swing.plaf.ComponentUI, # along with the special 'createUI' method. -keep class * extends javax.swing.plaf.ComponentUI { public static javax.swing.plaf.ComponentUI createUI(javax.swing.JComponent); } # Keep names - Native method names. Keep all native class/method names. -keepclasseswithmembers,allowshrinking class * { native <methods>; } # Keep names - _class method names. Keep all .class method names. This may be # useful for libraries that will be obfuscated again with different obfuscators. -keepclassmembers,allowshrinking class * { java.lang.Class class$(java.lang.String); java.lang.Class class$(java.lang.String,boolean); } Does anyone have an idea of how to solve this (apart from the obvious workaround to put the relevant files into a seperate jar and not obfuscate it)? Best regards, Stefan

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  • click buttons error

    - by sara
    I will retrieve student information (id -number- name) from a database (MySQL) as a list view, each student have 2 buttons (delete - alert ) and radio buttons Every thing is ok, but how can I make an onClickListener, for example for the delete button because I try lots of examples, I heard that I can use (custom list or get view or direct onClickListener as in my code (but it is not working ) or Simple Cursor Adapter) I do not know what to use, I looked around for examples that can help me, but in my case but I did not find any so I hope this be reference for anyone have the same problem. this is my code which I use direct onClick with Simple Adapter public class ManageSection extends ListActivity { //ProgresogressDialog pDialog; private ProgressDialog pDialog; // Creating JSON Parser object // Creating JSON Parser object JSONParser jParser = new JSONParser(); //class boolean x =true; Button delete; ArrayList<HashMap<String, String>> studentList; //url to get all products list private static String url_all_student = "http://10.0.2.2/SmsPhp/view_student_info.php"; String cl; // JSON Node names private static final String TAG_SUCCESS = "success"; private static final String TAG_student = "student"; private static final String TAG_StudentID = "StudentID"; private static final String TAG_StudentNo = "StudentNo"; private static final String TAG_FullName = "FullName"; private static final String TAG_Avatar="Avatar"; HashMap<String, String> selected_student; // course JSONArray JSONArray student = null; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.manage_section); studentList = new ArrayList<HashMap<String, String>>(); ListView list1 = getListView(); list1.setAdapter(getListAdapter()); list1.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> adapterView, View view, int pos, long l) { selected_student =(HashMap<String, String>) studentList.get(pos); //member of your activity. delete =(Button)view.findViewById(R.id.DeleteStudent); cl=selected_student.get(TAG_StudentID); Toast.makeText(getBaseContext(),cl,Toast.LENGTH_LONG).show(); delete.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { Log.d("id: ",cl); Toast.makeText(getBaseContext(),cl,Toast.LENGTH_LONG).show(); } }); } }); new LoadAllstudent().execute(); } /** * Background Async Task to Load all student by making HTTP Request * */ class LoadAllstudent extends AsyncTask<String, String, String> { /** * Before starting background thread Show Progress Dialog * */ @Override protected void onPreExecute() { super.onPreExecute(); pDialog = new ProgressDialog(ManageSection.this); pDialog.setMessage("Loading student. Please wait..."); pDialog.setIndeterminate(false); } /** * getting All student from u r l * */ @Override protected String doInBackground(String... args) { // Building Parameters List<NameValuePair> params = new ArrayList<NameValuePair>(); // getting JSON string from URL JSONObject json = jParser.makeHttpRequest(url_all_student, "GET", params); // Check your log cat for JSON response Log.d("All student : ", json.toString()); try { // Checking for SUCCESS TAG int success = json.getInt(TAG_SUCCESS); if (success == 1) { // student found // Getting Array of course student = json.getJSONArray(TAG_student); // looping through All courses for (int i = 0; i < student.length(); i++)//course JSONArray { JSONObject c = student.getJSONObject(i); // read first // Storing each json item in variable String StudentID = c.getString(TAG_StudentID); String StudentNo = c.getString(TAG_StudentNo); String FullName = c.getString(TAG_FullName); // String Avatar = c.getString(TAG_Avatar); // creating new HashMap HashMap<String, String> map = new HashMap<String, String>(); // adding each child node to HashMap key => value map.put(TAG_StudentID, StudentID); map.put(TAG_StudentNo, StudentNo); map.put(TAG_FullName, FullName); // adding HashList to ArrayList studentList.add(map); } } else { x=false; } } catch (JSONException e) { e.printStackTrace(); } return null; } /** * After completing background task Dismiss the progress dialog * **/ protected void onPostExecute(String file_url) { // dismiss the dialog after getting all products pDialog.dismiss(); if (x==false) Toast.makeText(getBaseContext(),"no student" ,Toast.LENGTH_LONG).show(); ListAdapter adapter = new SimpleAdapter( ManageSection.this, studentList, R.layout.list_student, new String[] { TAG_StudentID, TAG_StudentNo,TAG_FullName}, new int[] { R.id.StudentID, R.id.StudentNo,R.id.FullName}); setListAdapter(adapter); // Updating parsed JSON data into ListView } } } So what do you think, why doesn't the delete button work? There is no error in my log cat. What is the alternative way ?.. what should I do ?

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  • Java Array Index Out of Bounds Exception

    - by user1302023
    I need help debugging the following program: I'm getting a run time error that reads: Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: -1 at SearchEngine.main(SearchEngine.java:126) import java.util.*; import java.io.*; public class SearchEngine { public static int getNumberOfWords (File f) throws FileNotFoundException { int numWords = 0; Scanner scan = new Scanner(f); while (scan.hasNext()) { numWords++; scan.next(); } scan.close(); return numWords; } public static void readInWords (File input, String [] x) throws FileNotFoundException { Scanner scan = new Scanner(input); int i = 0; while (scan.hasNext() && i<x.length) { x[i] = scan.next(); i++; } scan.close(); } public static int getNumOfDistinctWords (File input, String [] x) throws FileNotFoundException { Scanner scan = new Scanner(input); int count = 0; int i = 1; while (scan.hasNext() && i<x.length) { if (!x[i].equals(x[i-1])) { count++; } i++; } scan.close(); return count; } public static void readInDistinctWords (String [] x, String [] y) { int i = 1; int k = 0; while (i<x.length) { if (!x[i].equals(x[i-1])) { y[k] = x[i]; k++; } i++; } } public static int getNumberOfLines (File input) throws FileNotFoundException { int numLines = 0; Scanner scan = new Scanner(input); while (scan.hasNextLine()) { numLines++; scan.nextLine(); } scan.close(); return numLines; } public static void readInLines (File input, String [] x) throws FileNotFoundException { Scanner scan = new Scanner(input); int i = 0; while (scan.hasNextLine() && i<x.length) { x[i] = scan.nextLine(); i++; } scan.close(); } public static void main(String [] args) { try { //gets file name System.out.println("Enter the name of the text file you wish to search"); Scanner kb = new Scanner(System.in); String fileName = kb.nextLine(); String TXT = ".txt"; if (!fileName.endsWith(TXT)) { fileName = fileName.concat(TXT); } File input = new File(fileName); //First part of creating index System.out.println("Creating vocabArray"); int NUM_WORDS = getNumberOfWords(input); //System.out.println(NUM_WORDS); String [] wordArray = new String[NUM_WORDS]; readInWords(input, wordArray); Arrays.sort(wordArray); int NUM_DISTINCT_WORDS = getNumOfDistinctWords(input, wordArray); String [] vocabArray = new String[NUM_DISTINCT_WORDS]; readInDistinctWords(wordArray, vocabArray); System.out.println("Finished creating vocabArray"); System.out.println("Creating concordanceArray"); int NUM_LINES = getNumberOfLines(input); String [] concordanceArray = new String[NUM_LINES]; readInLines(input, concordanceArray); System.out.println("Finished creating concordanceArray"); System.out.println("Creating invertedIndex"); int [][] invertedIndex = new int[NUM_DISTINCT_WORDS][10]; int [] wordCountArray = new int[NUM_DISTINCT_WORDS]; int lineNum = 0; while (lineNum<concordanceArray.length) { Scanner scan = new Scanner(concordanceArray[lineNum]); while (scan.hasNext()) { int wordPos = Arrays.binarySearch(vocabArray, scan.next()); wordCountArray[wordPos]+=1; for(int i = 0; i < invertedIndex.length; i++) { for(int j = 0; j < invertedIndex[i].length; j++) { if (invertedIndex[i][j] == 0) { invertedIndex[i][j] = lineNum; break; } } } } lineNum++; } System.out.println("Finished creating invertedIndex"); } catch (FileNotFoundException exception) { System.out.println("File Not Found"); } } //main } //class

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  • How to give position zero of spinner a prompt value?

    - by Eugene H
    The database is then transferring the data to a spinner which I want to leave position 0 blank so I can add a item to the spinner with no value making it look like a prompt. I have been going at it all day. FAil after Fail MainActivity public class MainActivity extends Activity { Button AddBtn; EditText et; EditText cal; Spinner spn; SQLController SQLcon; ProgressDialog PD; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); AddBtn = (Button) findViewById(R.id.addbtn_id); et = (EditText) findViewById(R.id.et_id); cal = (EditText) findViewById(R.id.et_cal); spn = (Spinner) findViewById(R.id.spinner_id); spn.setOnItemSelectedListener(new OnItemSelectedListenerWrapper( new OnItemSelectedListener() { @Override public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) { SQLcon.open(); Cursor c = SQLcon.readData(); if (c.moveToPosition(pos)) { String name = c.getString(c .getColumnIndex(DBhelper.MEMBER_NAME)); String calories = c.getString(c .getColumnIndex(DBhelper.KEY_CALORIES)); et.setText(name); cal.setText(calories); } SQLcon.close(); // closing database } @Override public void onNothingSelected(AdapterView<?> parent) { // TODO Auto-generated method stub } })); SQLcon = new SQLController(this); // opening database SQLcon.open(); loadtospinner(); AddBtn.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { new MyAsync().execute(); } }); } public void loadtospinner() { ArrayList<String> al = new ArrayList<String>(); Cursor c = SQLcon.readData(); c.moveToFirst(); while (!c.isAfterLast()) { String name = c.getString(c.getColumnIndex(DBhelper.MEMBER_NAME)); String calories = c.getString(c .getColumnIndex(DBhelper.KEY_CALORIES)); al.add(name + ", Calories: " + calories); c.moveToNext(); } ArrayAdapter<String> aa1 = new ArrayAdapter<String>( getApplicationContext(), android.R.layout.simple_spinner_item, al); spn.setAdapter(aa1); // closing database SQLcon.close(); } private class MyAsync extends AsyncTask<Void, Void, Void> { @Override protected void onPreExecute() { super.onPreExecute(); PD = new ProgressDialog(MainActivity.this); PD.setTitle("Please Wait.."); PD.setMessage("Loading..."); PD.setCancelable(false); PD.show(); } @Override protected Void doInBackground(Void... params) { String name = et.getText().toString(); String calories = cal.getText().toString(); // opening database SQLcon.open(); // insert data into table SQLcon.insertData(name, calories); return null; } @Override protected void onPostExecute(Void result) { super.onPostExecute(result); loadtospinner(); PD.dismiss(); } } } DataBase public class SQLController { private DBhelper dbhelper; private Context ourcontext; private SQLiteDatabase database; public SQLController(Context c) { ourcontext = c; } public SQLController open() throws SQLException { dbhelper = new DBhelper(ourcontext); database = dbhelper.getWritableDatabase(); return this; } public void close() { dbhelper.close(); } public void insertData(String name, String calories) { ContentValues cv = new ContentValues(); cv.put(DBhelper.MEMBER_NAME, name); cv.put(DBhelper.KEY_CALORIES, calories); database.insert(DBhelper.TABLE_MEMBER, null, cv); } public Cursor readData() { String[] allColumns = new String[] { DBhelper.MEMBER_ID, DBhelper.MEMBER_NAME, DBhelper.KEY_CALORIES }; Cursor c = database.query(DBhelper.TABLE_MEMBER, allColumns, null, null, null, null, null); if (c != null) { c.moveToFirst(); } return c; } } Helper public class DBhelper extends SQLiteOpenHelper { // TABLE INFORMATTION public static final String TABLE_MEMBER = "member"; public static final String MEMBER_ID = "_id"; public static final String MEMBER_NAME = "name"; public static final String KEY_CALORIES = "calories"; // DATABASE INFORMATION static final String DB_NAME = "MEMBER.DB"; static final int DB_VERSION = 2; // TABLE CREATION STATEMENT private static final String CREATE_TABLE = "create table " + TABLE_MEMBER + "(" + MEMBER_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + MEMBER_NAME + " TEXT NOT NULL," + KEY_CALORIES + " INT NOT NULL);"; public DBhelper(Context context) { super(context, DB_NAME, null, DB_VERSION); } @Override public void onCreate(SQLiteDatabase db) { db.execSQL(CREATE_TABLE); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { // TODO Auto-generated method stub db.execSQL("DROP TABLE IF EXISTS " + TABLE_MEMBER); onCreate(db); } }

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  • DD-WRT No Internet connection over LAN

    - by algorithms
    I flashed the DD-WRT firmware on my TP-Link WR1043ND router and although after cloning the PC's MAC-Address it gets the correct IP from my ISP, the internet connection over LAN just won't work. The strange thing is it does work flawlessly over W-LAN, which tells me the problem should lie somehow in the default LAN settings or the PC. Any idea what the problem might be? UPDATE: It seems the problem is the desktop PC, since the laptop can connect to the interet via ethernet without any problems. ipconfig /all seems totally normal (dhcp, dns, gateway all set to 192.168.1.1) I already tried the following things without success: disabling firewall rebooting router/modem/pc router hard-reset resetting tcp/ip and winsock manual setting of DNS/IP/Gateway Here is the ipconfig /all: Windows-IP-Konfiguration Hostname . . . . . . . . . . . . : Nitro-PC Primäres DNS-Suffix . . . . . . . : Knotentyp . . . . . . . . . . . . : Hybrid IP-Routing aktiviert . . . . . . : Nein WINS-Proxy aktiviert . . . . . . : Nein Ethernet-Adapter LAN-Verbindung 2: Medienstatus. . . . . . . . . . . : Medium getrennt Verbindungsspezifisches DNS-Suffix: Beschreibung. . . . . . . . . . . : TAP-Win32 Adapter V9 Physikalische Adresse . . . . . . : 00-FF-56-CA-66-8D DHCP aktiviert. . . . . . . . . . : Ja Autokonfiguration aktiviert . . . : Ja Ethernet-Adapter LAN-Verbindung: Verbindungsspezifisches DNS-Suffix: Beschreibung. . . . . . . . . . . : Realtek PCIe GBE Family Controller Physikalische Adresse . . . . . . : 48-5B-39-5B-DE-17 DHCP aktiviert. . . . . . . . . . : Ja Autokonfiguration aktiviert . . . : Ja Verbindungslokale IPv6-Adresse . : fe80::6934:b121:9eab:c6ce%10(Bevorzugt) IPv4-Adresse . . . . . . . . . . : 192.168.1.18(Bevorzugt) Subnetzmaske . . . . . . . . . . : 255.255.255.0 Lease erhalten. . . . . . . . . . : Donnerstag, 30. August 2012 10:52:30 Lease läuft ab. . . . . . . . . . : Freitag, 31. August 2012 10:52:30 Standardgateway . . . . . . . . . : 192.168.1.1 DHCP-Server . . . . . . . . . . . : 192.168.1.1 DHCPv6-IAID . . . . . . . . . . . : 239622969 DHCPv6-Client-DUID. . . . . . . . : 00-01-00-01-17-43-0D-B2-48-5B-39-5B-DE-17 DNS-Server . . . . . . . . . . . : 192.168.1.1 NetBIOS über TCP/IP . . . . . . . : Aktiviert Tunneladapter isatap.{56CA668D-9112-4399-9D9A-F1D42F0E52DE}: Medienstatus. . . . . . . . . . . : Medium getrennt Verbindungsspezifisches DNS-Suffix: Beschreibung. . . . . . . . . . . : Microsoft-ISATAP-Adapter Physikalische Adresse . . . . . . : 00-00-00-00-00-00-00-E0 DHCP aktiviert. . . . . . . . . . : Nein Autokonfiguration aktiviert . . . : Ja Tunneladapter Teredo Tunneling Pseudo-Interface: Verbindungsspezifisches DNS-Suffix: Beschreibung. . . . . . . . . . . : Teredo Tunneling Pseudo-Interface Physikalische Adresse . . . . . . : 00-00-00-00-00-00-00-E0 DHCP aktiviert. . . . . . . . . . : Nein Autokonfiguration aktiviert . . . : Ja IPv6-Adresse. . . . . . . . . . . : 2001:0:5ef5:79fd:1432:3dcd:3f57:feed(Bevorzugt) Verbindungslokale IPv6-Adresse . : fe80::1432:3dcd:3f57:feed%12(Bevorzugt) Standardgateway . . . . . . . . . : :: NetBIOS über TCP/IP . . . . . . . : Deaktiviert Tunneladapter isatap.{AD21069D-D2AF-423E-BF59-0B1CD0D235E8}: Medienstatus. . . . . . . . . . . : Medium getrennt Verbindungsspezifisches DNS-Suffix: Beschreibung. . . . . . . . . . . : Microsoft-ISATAP-Adapter #2 Physikalische Adresse . . . . . . : 00-00-00-00-00-00-00-E0 DHCP aktiviert. . . . . . . . . . : Nein Autokonfiguration aktiviert . . . : Ja Tunneladapter 6TO4 Adapter: Medienstatus. . . . . . . . . . . : Medium getrennt Verbindungsspezifisches DNS-Suffix: Beschreibung. . . . . . . . . . . : Microsoft-6zu4-Adapter Physikalische Adresse . . . . . . : 00-00-00-00-00-00-00-E0 DHCP aktiviert. . . . . . . . . . : Nein Autokonfiguration aktiviert . . . : Ja route PRINT IPv4-Routentabelle =========================================================================== Aktive Routen: Netzwerkziel Netzwerkmaske Gateway Schnittstelle Metrik 0.0.0.0 0.0.0.0 192.168.1.1 192.168.1.18 10 127.0.0.0 255.0.0.0 Auf Verbindung 127.0.0.1 306 127.0.0.1 255.255.255.255 Auf Verbindung 127.0.0.1 306 127.255.255.255 255.255.255.255 Auf Verbindung 127.0.0.1 306 192.168.1.0 255.255.255.0 Auf Verbindung 192.168.1.18 266 192.168.1.18 255.255.255.255 Auf Verbindung 192.168.1.18 266 192.168.1.255 255.255.255.255 Auf Verbindung 192.168.1.18 266 224.0.0.0 240.0.0.0 Auf Verbindung 127.0.0.1 306 224.0.0.0 240.0.0.0 Auf Verbindung 192.168.1.18 266 255.255.255.255 255.255.255.255 Auf Verbindung 127.0.0.1 306 255.255.255.255 255.255.255.255 Auf Verbindung 192.168.1.18 266 =========================================================================== Stndige Routen: Keine

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  • Failure retrieving contents of directory

    - by Bondye
    Currently I have a couple of websites. My problem is that if I login on 1 specific domain with any of my programs (using notepadd++, FileZilla and Netbeans) the program stops at the content listing. I had it correctly running, (I'm working on a project on this domain for more than a year now) and suddenly I broke it somehow. This only happens on 1 specific domain, all other domains (from other hosts) are working. My colleague (next to me with same ip address) is able to login on this domain. Notepadd++ says: Failure retrieving contents of directory Filezilla says: Failed to retrieve directory listing Netbean popups: Upload files on save failed. (Because I have the setting upload on save enabled.) What I tried: First I thought it's my firewall, I disabled firewall but no result. Also notice that all other domain are working. Maby a blacklist with my ip address? No my colleague has the same ip address. Could anyone help me on this? Notepad++ Log [NppFTP] Everything initialized -> TYPE I Connecting -> Quit 220 ProFTPD 1.3.3e Server ready. -> USER username 331 Password required for domain -> PASS *HIDDEN* 230 User username logged in -> TYPE A 200 Type set to A -> MODE S 200 Mode set to S -> STRU F 200 Structure set to F -> CWD /domains/domain.nl/ 250 CWD command successful Connected -> CWD /domains/domain.nl/ 250 CWD command successful -> PASV 227 Entering Passive Mode (194,247,31,xx,137,xx). -> LIST -al Failure retrieving contents of directory /domains/domain.nl/ Filezilla log Status: Verbinden met 194.247.xx.xx:21... Status: Verbinding aangemaakt, welkomstbericht afwachten... Antwoord: 220 ProFTPD 1.3.3e Server ready. Commando: USER username Antwoord: 331 Password required for username Commando: PASS ******** Antwoord: 230 User username logged in Commando: SYST Antwoord: 215 UNIX Type: L8 Commando: FEAT Antwoord: 211-Features: Antwoord: MDTM Antwoord: MFMT Antwoord: LANG en-US;ja-JP;zh-TW;it-IT;fr-FR;zh-CN;ru-RU;bg-BG;ko-KR Antwoord: TVFS Antwoord: UTF8 Antwoord: AUTH TLS Antwoord: MFF modify;UNIX.group;UNIX.mode; Antwoord: MLST modify*;perm*;size*;type*;unique*;UNIX.group*;UNIX.mode*;UNIX.owner*; Antwoord: PBSZ Antwoord: PROT Antwoord: REST STREAM Antwoord: SIZE Antwoord: 211 End Commando: OPTS UTF8 ON Antwoord: 200 UTF8 set to on Status: Verbonden Status: Mappenlijst ophalen... Commando: PWD Antwoord: 257 "/" is the current directory Commando: TYPE I Antwoord: 200 Type set to I Commando: PASV Antwoord: 227 Entering Passive Mode (194,247,31,xx,xxx,xx). Commando: MLSD Fout: Verbinding verloren Fout: Ontvangen van mappenlijst is mislukt Sorry that it's dutch.

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  • Connecting Linux to WatchGuard Firebox SSL (OpenVPN client)

    Recently, I got a new project assignment that requires to connect permanently to the customer's network through VPN. They are using a so-called SSL VPN. As I am using OpenVPN since more than 5 years within my company's network I was quite curious about their solution and how it would actually be different from OpenVPN. Well, short version: It is a disguised version of OpenVPN. Unfortunately, the company only offers a client for Windows and Mac OS which shouldn't bother any Linux user after all. OpenVPN is part of every recent distribution and can be activated in a couple of minutes - both client as well as server (if necessary). WatchGuard Firebox SSL - About dialog Borrowing some files from a Windows client installation Initially, I didn't know about the product, so therefore I went through the installation on Windows 8. No obstacles (and no restart despite installation of TAP device drivers!) here and the secured VPN channel was up and running in less than 2 minutes or so. Much appreciated from both parties - customer and me. Of course, this whole client package and my long year approved and stable installation ignited my interest to have a closer look at the WatchGuard client. Compared to the original OpenVPN client (okay, I have to admit this is years ago) this commercial product is smarter in terms of file locations during installation. You'll be able to access the configuration and key files below your roaming application data folder. To get there, simply enter '%AppData%\WatchGuard\Mobile VPN' in your Windows/File Explorer and confirm with Enter/Return. This will display the following files: Application folder below user profile with configuration and certificate files From there we are going to borrow four files, namely: ca.crt client.crt client.ovpn client.pem and transfer them to the Linux system. You might also be able to isolate those four files from a Mac OS client. Frankly, I'm just too lazy to run the WatchGuard client installation on a Mac mini only to find the folder location, and I'm going to describe why a little bit further down this article. I know that you can do that! Feedback in the comment section is appreciated. Configuration of OpenVPN (console) Depending on your distribution the following steps might be a little different but in general you should be able to get the important information from it. I'm going to describe the steps in Ubuntu 13.04 (Raring Ringtail). As usual, there are two possibilities to achieve your goal: console and UI. Let's what it is necessary to be done. First of all, you should ensure that you have OpenVPN installed on your system. Open your favourite terminal application and run the following statement: $ sudo apt-get install openvpn network-manager-openvpn network-manager-openvpn-gnome Just to be on the safe side. The four above mentioned files from your Windows machine could be copied anywhere but either you place them below your own user directory or you put them (as root) below the default directory: /etc/openvpn At this stage you would be able to do a test run already. Just in case, run the following command and check the output (it's the similar information you would get from the 'View Logs...' context menu entry in Windows: $ sudo openvpn --config client.ovpn Pay attention to the correct path to your configuration and certificate files. OpenVPN will ask you to enter your Auth Username and Auth Password in order to establish the VPN connection, same as the Windows client. Remote server and user authentication to establish the VPN Please complete the test run and see whether all went well. You can disconnect pressing Ctrl+C. Simplifying your life - authentication file In my case, I actually set up the OpenVPN client on my gateway/router. This establishes a VPN channel between my network and my client's network and allows me to switch machines easily without having the necessity to install the WatchGuard client on each and every machine. That's also very handy for my various virtualised Windows machines. Anyway, as the client configuration, key and certificate files are located on a headless system somewhere under the roof, it is mandatory to have an automatic connection to the remote site. For that you should first change the file extension '.ovpn' to '.conf' which is the default extension on Linux systems for OpenVPN, and then open the client configuration file in order to extend an existing line. $ sudo mv client.ovpn client.conf $ sudo nano client.conf You should have a similar content to this one here: dev tunclientproto tcp-clientca ca.crtcert client.crtkey client.pemtls-remote "/O=WatchGuard_Technologies/OU=Fireware/CN=Fireware_SSLVPN_Server"remote-cert-eku "TLS Web Server Authentication"remote 1.2.3.4 443persist-keypersist-tunverb 3mute 20keepalive 10 60cipher AES-256-CBCauth SHA1float 1reneg-sec 3660nobindmute-replay-warningsauth-user-pass auth.txt Note: I changed the IP address of the remote directive above (which should be obvious, right?). Anyway, the required change is marked in red and we have to create a new authentication file 'auth.txt'. You can give the directive 'auth-user-pass' any file name you'd like to. Due to my existing OpenVPN infrastructure my setup differs completely from the above written content but for sake of simplicity I just keep it 'as-is'. Okay, let's create this file 'auth.txt' $ sudo nano auth.txt and just put two lines of information in it - username on the first, and password on the second line, like so: myvpnusernameverysecretpassword Store the file, change permissions, and call openvpn with your configuration file again: $ sudo chmod 0600 auth.txt $ sudo openvpn --config client.conf This should now work without being prompted to enter username and password. In case that you placed your files below the system-wide location /etc/openvpn you can operate your VPNs also via service command like so: $ sudo service openvpn start client $ sudo service openvpn stop client Using Network Manager For newer Linux users or the ones with 'console-phobia' I'm going to describe now how to use Network Manager to setup the OpenVPN client. For this move your mouse to the systray area and click on Network Connections => VPN Connections => Configure VPNs... which opens your Network Connections dialog. Alternatively, use the HUD and enter 'Network Connections'. Network connections overview in Ubuntu Click on 'Add' button. On the next dialog select 'Import a saved VPN configuration...' from the dropdown list and click on 'Create...' Choose connection type to import VPN configuration Now you navigate to your folder where you put the client files from the Windows system and you open the 'client.ovpn' file. Next, on the tab 'VPN' proceed with the following steps (directives from the configuration file are referred): General Check the IP address of Gateway ('remote' - we used 1.2.3.4 in this setup) Authentication Change Type to 'Password with Certificates (TLS)' ('auth-pass-user') Enter User name to access your client keys (Auth Name: myvpnusername) Enter Password (Auth Password: verysecretpassword) and choose your password handling Browse for your User Certificate ('cert' - should be pre-selected with client.crt) Browse for your CA Certificate ('ca' - should be filled as ca.crt) Specify your Private Key ('key' - here: client.pem) Then click on the 'Advanced...' button and check the following values: Use custom gateway port: 443 (second value of 'remote' directive) Check the selected value of Cipher ('cipher') Check HMAC Authentication ('auth') Enter the Subject Match: /O=WatchGuard_Technologies/OU=Fireware/CN=Fireware_SSLVPN_Server ('tls-remote') Finally, you have to confirm and close all dialogs. You should be able to establish your OpenVPN-WatchGuard connection via Network Manager. For that, click on the 'VPN Connections => client' entry on your Network Manager in the systray. It is advised that you keep an eye on the syslog to see whether there are any problematic issues that would require some additional attention. Advanced topic: routing As stated above, I'm running the 'WatchGuard client for Linux' on my head-less server, and since then I'm actually establishing a secure communication channel between two networks. In order to enable your network clients to get access to machines on the remote side there are two possibilities to enable that: Proper routing on both sides of the connection which enables both-direction access, or Network masquerading on the 'client side' of the connection Following, I'm going to describe the second option a little bit more in detail. The Linux system that I'm using is already configured as a gateway to the internet. I won't explain the necessary steps to do that, and will only focus on the additional tweaks I had to do. You can find tons of very good instructions and tutorials on 'How to setup a Linux gateway/router' - just use Google. OK, back to the actual modifications. First, we need to have some information about the network topology and IP address range used on the 'other' side. We can get this very easily from /var/log/syslog after we established the OpenVPN channel, like so: $ sudo tail -n20 /var/log/syslog Or if your system is quite busy with logging, like so: $ sudo less /var/log/syslog | grep ovpn The output should contain PUSH received message similar to the following one: Jul 23 23:13:28 ios1 ovpn-client[789]: PUSH: Received control message: 'PUSH_REPLY,topology subnet,route 192.168.1.0 255.255.255.0,dhcp-option DOMAIN ,route-gateway 192.168.6.1,topology subnet,ping 10,ping-restart 60,ifconfig 192.168.6.2 255.255.255.0' The interesting part for us is the route command which I highlighted already in the sample PUSH_REPLY. Depending on your remote server there might be multiple networks defined (172.16.x.x and/or 10.x.x.x). Important: The IP address range on both sides of the connection has to be different, otherwise you will have to shuffle IPs or increase your the netmask. {loadposition content_adsense} After the VPN connection is established, we have to extend the rules for iptables in order to route and masquerade IP packets properly. I created a shell script to take care of those steps: #!/bin/sh -eIPTABLES=/sbin/iptablesDEV_LAN=eth0DEV_VPNS=tun+VPN=192.168.1.0/24 $IPTABLES -A FORWARD -i $DEV_LAN -o $DEV_VPNS -d $VPN -j ACCEPT$IPTABLES -A FORWARD -i $DEV_VPNS -o $DEV_LAN -s $VPN -j ACCEPT$IPTABLES -t nat -A POSTROUTING -o $DEV_VPNS -d $VPN -j MASQUERADE I'm using the wildcard interface 'tun+' because I have multiple client configurations for OpenVPN on my server. In your case, it might be sufficient to specify device 'tun0' only. Simplifying your life - automatic connect on boot Now, that the client connection works flawless, configuration of routing and iptables is okay, we might consider to add another 'laziness' factor into our setup. Due to kernel updates or other circumstances it might be necessary to reboot your system. Wouldn't it be nice that the VPN connections are established during the boot procedure? Yes, of course it would be. To achieve this, we have to configure OpenVPN to automatically start our VPNs via init script. Let's have a look at the responsible 'default' file and adjust the settings accordingly. $ sudo nano /etc/default/openvpn Which should have a similar content to this: # This is the configuration file for /etc/init.d/openvpn## Start only these VPNs automatically via init script.# Allowed values are "all", "none" or space separated list of# names of the VPNs. If empty, "all" is assumed.# The VPN name refers to the VPN configutation file name.# i.e. "home" would be /etc/openvpn/home.conf#AUTOSTART="all"#AUTOSTART="none"#AUTOSTART="home office"## ... more information which remains unmodified ... With the OpenVPN client configuration as described above you would either set AUTOSTART to "all" or to "client" to enable automatic start of your VPN(s) during boot. You should also take care that your iptables commands are executed after the link has been established, too. You can easily test this configuration without reboot, like so: $ sudo service openvpn restart Enjoy stable VPN connections between your Linux system(s) and a WatchGuard Firebox SSL remote server. Cheers, JoKi

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  • Setting up a local AI server - easy with Solaris 11

    - by Stefan Hinker
    Many things are new in Solaris 11, Autoinstall is one of them.  If, like me, you've known Jumpstart for the last 2 centuries or so, you'll have to start from scratch.  Well, almost, as the concepts are similar, and it's not all that difficult.  Just new. I wanted to have an AI server that I could use for demo purposes, on the train if need be.  That answers the question of hardware requirements: portable.  But let's start at the beginning. First, you need an OS image, of course.  In the new world of Solaris 11, it is now called a repository.  The original can be downloaded from the Solaris 11 page at Oracle.   What you want is the "Oracle Solaris 11 11/11 Repository Image", which comes in two parts that can be combined using cat.  MD5 checksums for these (and all other downloads from that page) are available closer to the top of the page. With that, building the repository is quick and simple: # zfs create -o mountpoint=/export/repo rpool/ai/repo # zfs create rpool/ai/repo/s11 # mount -o ro -F hsfs /tmp/sol-11-1111-repo-full.iso /mnt # rsync -aP /mnt/repo /export/repo/s11 # umount /mnt # pkgrepo rebuild -s /export/repo/sol11/repo # zfs snapshot rpool/ai/repo/sol11@fcs # pkgrepo info -s /export/repo/sol11/repo PUBLISHER PACKAGES STATUS UPDATED solaris 4292 online 2012-03-12T20:47:15.378639Z That's all there's to it.  Let's make a snapshot, just to be on the safe side.  You never know when one will come in handy.  To use this repository, you could just add it as a file-based publisher: # pkg set-publisher -g file:///export/repo/sol11/repo solaris In case I'd want to access this repository through a (virtual) network, i'll now quickly activate the repository-service: # svccfg -s application/pkg/server \ setprop pkg/inst_root=/export/repo/sol11/repo # svccfg -s application/pkg/server setprop pkg/readonly=true # svcadm refresh application/pkg/server # svcadm enable application/pkg/server That's all you need - now point your browser to http://localhost/ to view your beautiful repository-server. Step 1 is done.  All of this, by the way, is nicely documented in the README file that's contained in the repository image. Of course, we already have updates to the original release.  You can find them in MOS in the Oracle Solaris 11 Support Repository Updates (SRU) Index.  You can simply add these to your existing repository or create separate repositories for each SRU.  The individual SRUs are self-sufficient and incremental - SRU4 includes all updates from SRU2 and SRU3.  With ZFS, you can also get both: A full repository with all updates and at the same time incremental ones up to each of the updates: # mount -o ro -F hsfs /tmp/sol-11-1111-sru4-05-incr-repo.iso /mnt # pkgrecv -s /mnt/repo -d /export/repo/sol11/repo '*' # umount /mnt # pkgrepo rebuild -s /export/repo/sol11/repo # zfs snapshot rpool/ai/repo/sol11@sru4 # zfs set snapdir=visible rpool/ai/repo/sol11 # svcadm restart svc:/application/pkg/server:default The normal repository is now updated to SRU4.  Thanks to the ZFS snapshots, there is also a valid repository of Solaris 11 11/11 without the update located at /export/repo/sol11/.zfs/snapshot/fcs . If you like, you can also create another repository service for each update, running on a separate port. But now lets continue with the AI server.  Just a little bit of reading in the dokumentation makes it clear that we will need to run a DHCP server for this.  Since I already have one active (for my SunRay installation) and since it's a good idea to have these kinds of services separate anyway, I decided to create this in a Zone.  So, let's create one first: # zfs create -o mountpoint=/export/install rpool/ai/install # zfs create -o mountpoint=/zones rpool/zones # zonecfg -z ai-server zonecfg:ai-server> create create: Using system default template 'SYSdefault' zonecfg:ai-server> set zonepath=/zones/ai-server zonecfg:ai-server> add dataset zonecfg:ai-server:dataset> set name=rpool/ai/install zonecfg:ai-server:dataset> set alias=install zonecfg:ai-server:dataset> end zonecfg:ai-server> commit zonecfg:ai-server> exit # zoneadm -z ai-server install # zoneadm -z ai-server boot ; zlogin -C ai-server Give it a hostname and IP address at first boot, and there's the Zone.  For a publisher for Solaris packages, it will be bound to the "System Publisher" from the Global Zone.  The /export/install filesystem, of course, is intended to be used by the AI server.  Let's configure it now: #zlogin ai-server root@ai-server:~# pkg install install/installadm root@ai-server:~# installadm create-service -n x86-fcs -a i386 \ -s pkg://solaris/install-image/[email protected],5.11-0.175.0.0.0.2.1482 \ -d /export/install/fcs -i 192.168.2.20 -c 3 With that, the core AI server is already done.  What happened here?  First, I installed the AI server software.  IPS makes that nice and easy.  If necessary, it'll also pull in the required DHCP-Server and anything else that might be missing.  Watch out for that DHCP server software.  In Solaris 11, there are two different versions.  There's the one you might know from Solaris 10 and earlier, and then there's a new one from ISC.  The latter is the one we need for AI.  The SMF service names of both are very similar.  The "old" one is "svc:/network/dhcp-server:default". The ISC-server comes with several SMF-services. We at least need "svc:/network/dhcp/server:ipv4".  The command "installadm create-service" creates the installation-service. It's called "x86-fcs", serves the "i386" architecture and gets its boot image from the repository of the system publisher, using version 5.11,5.11-0.175.0.0.0.2.1482, which is Solaris 11 11/11.  (The option "-a i386" in this example is optional, since the installserver itself runs on a x86 machine.) The boot-environment for clients is created in /export/install/fcs and the DHCP-server is configured for 3 IP-addresses starting at 192.168.2.20.  This configuration is stored in a very human readable form in /etc/inet/dhcpd4.conf.  An AI-service for SPARC systems could be created in the very same way, using "-a sparc" as the architecture option. Now we would be ready to register and install the first client.  It would be installed with the default "solaris-large-server" using the publisher "http://pkg.oracle.com/solaris/release" and would query it's configuration interactively at first boot.  This makes it very clear that an AI-server is really only a boot-server.  The true source of packets to install can be different.  Since I don't like these defaults for my demo setup, I did some extra config work for my clients. The configuration of a client is controlled by manifests and profiles.  The manifest controls which packets are installed and how the filesystems are layed out.  In that, it's very much like the old "rules.ok" file in Jumpstart.  Profiles contain additional configuration like root passwords, primary user account, IP addresses, keyboard layout etc.  Hence, profiles are very similar to the old sysid.cfg file. The easiest way to get your hands on a manifest is to ask the AI server we just created to give us it's default one.  Then modify that to our liking and give it back to the installserver to use: root@ai-server:~# mkdir -p /export/install/configs/manifests root@ai-server:~# cd /export/install/configs/manifests root@ai-server:~# installadm export -n x86-fcs -m orig_default \ -o orig_default.xml root@ai-server:~# cp orig_default.xml s11-fcs.small.local.xml root@ai-server:~# vi s11-fcs.small.local.xml root@ai-server:~# more s11-fcs.small.local.xml <!DOCTYPE auto_install SYSTEM "file:///usr/share/install/ai.dtd.1"> <auto_install> <ai_instance name="S11 Small fcs local"> <target> <logical> <zpool name="rpool" is_root="true"> <filesystem name="export" mountpoint="/export"/> <filesystem name="export/home"/> <be name="solaris"/> </zpool> </logical> </target> <software type="IPS"> <destination> <image> <!-- Specify locales to install --> <facet set="false">facet.locale.*</facet> <facet set="true">facet.locale.de</facet> <facet set="true">facet.locale.de_DE</facet> <facet set="true">facet.locale.en</facet> <facet set="true">facet.locale.en_US</facet> </image> </destination> <source> <publisher name="solaris"> <origin name="http://192.168.2.12/"/> </publisher> </source> <!-- By default the latest build available, in the specified IPS repository, is installed. If another build is required, the build number has to be appended to the 'entire' package in the following form: <name>pkg:/[email protected]#</name> --> <software_data action="install"> <name>pkg:/[email protected],5.11-0.175.0.0.0.2.0</name> <name>pkg:/group/system/solaris-small-server</name> </software_data> </software> </ai_instance> </auto_install> root@ai-server:~# installadm create-manifest -n x86-fcs -d \ -f ./s11-fcs.small.local.xml root@ai-server:~# installadm list -m -n x86-fcs Manifest Status Criteria -------- ------ -------- S11 Small fcs local Default None orig_default Inactive None The major points in this new manifest are: Install "solaris-small-server" Install a few locales less than the default.  I'm not that fluid in French or Japanese... Use my own package service as publisher, running on IP address 192.168.2.12 Install the initial release of Solaris 11:  pkg:/[email protected],5.11-0.175.0.0.0.2.0 Using a similar approach, I'll create a default profile interactively and use it as a template for a few customized building blocks, each defining a part of the overall system configuration.  The modular approach makes it easy to configure numerous clients later on: root@ai-server:~# mkdir -p /export/install/configs/profiles root@ai-server:~# cd /export/install/configs/profiles root@ai-server:~# sysconfig create-profile -o default.xml root@ai-server:~# cp default.xml general.xml; cp default.xml mars.xml root@ai-server:~# cp default.xml user.xml root@ai-server:~# vi general.xml mars.xml user.xml root@ai-server:~# more general.xml mars.xml user.xml :::::::::::::: general.xml :::::::::::::: <!DOCTYPE service_bundle SYSTEM "/usr/share/lib/xml/dtd/service_bundle.dtd.1"> <service_bundle type="profile" name="sysconfig"> <service version="1" type="service" name="system/timezone"> <instance enabled="true" name="default"> <property_group type="application" name="timezone"> <propval type="astring" name="localtime" value="Europe/Berlin"/> </property_group> </instance> </service> <service version="1" type="service" name="system/environment"> <instance enabled="true" name="init"> <property_group type="application" name="environment"> <propval type="astring" name="LANG" value="C"/> </property_group> </instance> </service> <service version="1" type="service" name="system/keymap"> <instance enabled="true" name="default"> <property_group type="system" name="keymap"> <propval type="astring" name="layout" value="US-English"/> </property_group> </instance> </service> <service version="1" type="service" name="system/console-login"> <instance enabled="true" name="default"> <property_group type="application" name="ttymon"> <propval type="astring" name="terminal_type" value="vt100"/> </property_group> </instance> </service> <service version="1" type="service" name="network/physical"> <instance enabled="true" name="default"> <property_group type="application" name="netcfg"> <propval type="astring" name="active_ncp" value="DefaultFixed"/> </property_group> </instance> </service> <service version="1" type="service" name="system/name-service/switch"> <property_group type="application" name="config"> <propval type="astring" name="default" value="files"/> <propval type="astring" name="host" value="files dns"/> <propval type="astring" name="printer" value="user files"/> </property_group> <instance enabled="true" name="default"/> </service> <service version="1" type="service" name="system/name-service/cache"> <instance enabled="true" name="default"/> </service> <service version="1" type="service" name="network/dns/client"> <property_group type="application" name="config"> <property type="net_address" name="nameserver"> <net_address_list> <value_node value="192.168.2.1"/> </net_address_list> </property> </property_group> <instance enabled="true" name="default"/> </service> </service_bundle> :::::::::::::: mars.xml :::::::::::::: <!DOCTYPE service_bundle SYSTEM "/usr/share/lib/xml/dtd/service_bundle.dtd.1"> <service_bundle type="profile" name="sysconfig"> <service version="1" type="service" name="network/install"> <instance enabled="true" name="default"> <property_group type="application" name="install_ipv4_interface"> <propval type="astring" name="address_type" value="static"/> <propval type="net_address_v4" name="static_address" value="192.168.2.100/24"/> <propval type="astring" name="name" value="net0/v4"/> <propval type="net_address_v4" name="default_route" value="192.168.2.1"/> </property_group> <property_group type="application" name="install_ipv6_interface"> <propval type="astring" name="stateful" value="yes"/> <propval type="astring" name="stateless" value="yes"/> <propval type="astring" name="address_type" value="addrconf"/> <propval type="astring" name="name" value="net0/v6"/> </property_group> </instance> </service> <service version="1" type="service" name="system/identity"> <instance enabled="true" name="node"> <property_group type="application" name="config"> <propval type="astring" name="nodename" value="mars"/> </property_group> </instance> </service> </service_bundle> :::::::::::::: user.xml :::::::::::::: <!DOCTYPE service_bundle SYSTEM "/usr/share/lib/xml/dtd/service_bundle.dtd.1"> <service_bundle type="profile" name="sysconfig"> <service version="1" type="service" name="system/config-user"> <instance enabled="true" name="default"> <property_group type="application" name="root_account"> <propval type="astring" name="login" value="root"/> <propval type="astring" name="password" value="noIWillNotTellYouMyPasswordNotEvenEncrypted"/> <propval type="astring" name="type" value="role"/> </property_group> <property_group type="application" name="user_account"> <propval type="astring" name="login" value="stefan"/> <propval type="astring" name="password" value="noIWillNotTellYouMyPasswordNotEvenEncrypted"/> <propval type="astring" name="type" value="normal"/> <propval type="astring" name="description" value="Stefan Hinker"/> <propval type="count" name="uid" value="12345"/> <propval type="count" name="gid" value="10"/> <propval type="astring" name="shell" value="/usr/bin/bash"/> <propval type="astring" name="roles" value="root"/> <propval type="astring" name="profiles" value="System Administrator"/> <propval type="astring" name="sudoers" value="ALL=(ALL) ALL"/> </property_group> </instance> </service> </service_bundle> root@ai-server:~# installadm create-profile -n x86-fcs -f general.xml root@ai-server:~# installadm create-profile -n x86-fcs -f user.xml root@ai-server:~# installadm create-profile -n x86-fcs -f mars.xml \ -c ipv4=192.168.2.100 root@ai-server:~# installadm list -p Service Name Profile ------------ ------- x86-fcs general.xml mars.xml user.xml root@ai-server:~# installadm list -n x86-fcs -p Profile Criteria ------- -------- general.xml None mars.xml ipv4 = 192.168.2.100 user.xml None Here's the idea behind these files: "general.xml" contains settings valid for all my clients.  Stuff like DNS servers, for example, which in my case will always be the same. "user.xml" only contains user definitions.  That is, a root password and a primary user.Both of these profiles will be valid for all clients (for now). "mars.xml" defines network settings for an individual client.  This profile is associated with an IP-Address.  For this to work, I'll have to tweak the DHCP-settings in the next step: root@ai-server:~# installadm create-client -e 08:00:27:AA:3D:B1 -n x86-fcs root@ai-server:~# vi /etc/inet/dhcpd4.conf root@ai-server:~# tail -5 /etc/inet/dhcpd4.conf host 080027AA3DB1 { hardware ethernet 08:00:27:AA:3D:B1; fixed-address 192.168.2.100; filename "01080027AA3DB1"; } This completes the client preparations.  I manually added the IP-Address for mars to /etc/inet/dhcpd4.conf.  This is needed for the "mars.xml" profile.  Disabling arbitrary DHCP-replies will shut up this DHCP server, making my life in a shared environment a lot more peaceful ;-)Now, I of course want this installation to be completely hands-off.  For this to work, I'll need to modify the grub boot menu for this client slightly.  You can find it in /etc/netboot.  "installadm create-client" will create a new boot menu for every client, identified by the client's MAC address.  The template for this can be found in a subdirectory with the name of the install service, /etc/netboot/x86-fcs in our case.  If you don't want to change this manually for every client, modify that template to your liking instead. root@ai-server:~# cd /etc/netboot root@ai-server:~# cp menu.lst.01080027AA3DB1 menu.lst.01080027AA3DB1.org root@ai-server:~# vi menu.lst.01080027AA3DB1 root@ai-server:~# diff menu.lst.01080027AA3DB1 menu.lst.01080027AA3DB1.org 1,2c1,2 < default=1 < timeout=10 --- > default=0 > timeout=30 root@ai-server:~# more menu.lst.01080027AA3DB1 default=1 timeout=10 min_mem64=0 title Oracle Solaris 11 11/11 Text Installer and command line kernel$ /x86-fcs/platform/i86pc/kernel/$ISADIR/unix -B install_media=htt p://$serverIP:5555//export/install/fcs,install_service=x86-fcs,install_svc_addre ss=$serverIP:5555 module$ /x86-fcs/platform/i86pc/$ISADIR/boot_archive title Oracle Solaris 11 11/11 Automated Install kernel$ /x86-fcs/platform/i86pc/kernel/$ISADIR/unix -B install=true,inst all_media=http://$serverIP:5555//export/install/fcs,install_service=x86-fcs,inst all_svc_address=$serverIP:5555,livemode=text module$ /x86-fcs/platform/i86pc/$ISADIR/boot_archive Now just boot the client off the network using PXE-boot.  For my demo purposes, that's a client from VirtualBox, of course.  That's all there's to it.  And despite the fact that this blog entry is a little longer - that wasn't that hard now, was it?

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  • Revisiting ANTS Performance Profiler 7.4

    - by James Michael Hare
    Last year, I did a small review on the ANTS Performance Profiler 6.3, now that it’s a year later and a major version number higher, I thought I’d revisit the review and revise my last post. This post will take the same examples as the original post and update them to show what’s new in version 7.4 of the profiler. Background A performance profiler’s main job is to keep track of how much time is typically spent in each unit of code. This helps when we have a program that is not running at the performance we expect, and we want to know where the program is experiencing issues. There are many profilers out there of varying capabilities. Red Gate’s typically seem to be the very easy to “jump in” and get started with very little training required. So let’s dig into the Performance Profiler. I’ve constructed a very crude program with some obvious inefficiencies. It’s a simple program that generates random order numbers (or really could be any unique identifier), adds it to a list, sorts the list, then finds the max and min number in the list. Ignore the fact it’s very contrived and obviously inefficient, we just want to use it as an example to show off the tool: 1: // our test program 2: public static class Program 3: { 4: // the number of iterations to perform 5: private static int _iterations = 1000000; 6: 7: // The main method that controls it all 8: public static void Main() 9: { 10: var list = new List<string>(); 11: 12: for (int i = 0; i < _iterations; i++) 13: { 14: var x = GetNextId(); 15: 16: AddToList(list, x); 17: 18: var highLow = GetHighLow(list); 19: 20: if ((i % 1000) == 0) 21: { 22: Console.WriteLine("{0} - High: {1}, Low: {2}", i, highLow.Item1, highLow.Item2); 23: Console.Out.Flush(); 24: } 25: } 26: } 27: 28: // gets the next order id to process (random for us) 29: public static string GetNextId() 30: { 31: var random = new Random(); 32: var num = random.Next(1000000, 9999999); 33: return num.ToString(); 34: } 35: 36: // add it to our list - very inefficiently! 37: public static void AddToList(List<string> list, string item) 38: { 39: list.Add(item); 40: list.Sort(); 41: } 42: 43: // get high and low of order id range - very inefficiently! 44: public static Tuple<int,int> GetHighLow(List<string> list) 45: { 46: return Tuple.Create(list.Max(s => Convert.ToInt32(s)), list.Min(s => Convert.ToInt32(s))); 47: } 48: } So let’s run it through the profiler and see what happens! Visual Studio Integration First, let’s look at how the ANTS profilers integrate with Visual Studio’s menu system. Once you install the ANTS profilers, you will get an ANTS menu item with several options: Notice that you can either Profile Performance or Launch ANTS Performance Profiler. These sound similar but achieve two slightly different actions: Profile Performance: this immediately launches the profiler with all defaults selected to profile the active project in Visual Studio. Launch ANTS Performance Profiler: this launches the profiler much the same way as starting it from the Start Menu. The profiler will pre-populate the application and path information, but allow you to change the settings before beginning the profile run. So really, the main difference is that Profile Performance immediately begins profiling with the default selections, where Launch ANTS Performance Profiler allows you to change the defaults and attach to an already-running application. Let’s Fire it Up! So when you fire up ANTS either via Start Menu or Launch ANTS Performance Profiler menu in Visual Studio, you are presented with a very simple dialog to get you started: Notice you can choose from many different options for application type. You can profile executables, services, web applications, or just attach to a running process. In fact, in version 7.4 we see two new options added: ASP.NET Web Application (IIS Express) SharePoint web application (IIS) So this gives us an additional way to profile ASP.NET applications and the ability to profile SharePoint applications as well. You can also choose your level of detail in the Profiling Mode drop down. If you choose Line-Level and method-level timings detail, you will get a lot more detail on the method durations, but this will also slow down profiling somewhat. If you really need the profiler to be as unintrusive as possible, you can change it to Sample method-level timings. This is performing very light profiling, where basically the profiler collects timings of a method by examining the call-stack at given intervals. Which method you choose depends a lot on how much detail you need to find the issue and how sensitive your program issues are to timing. So for our example, let’s just go with the line and method timing detail. So, we check that all the options are correct (if you launch from VS2010, the executable and path are filled in already), and fire it up by clicking the [Start Profiling] button. Profiling the Application Once you start profiling the application, you will see a real-time graph of CPU usage that will indicate how much your application is using the CPU(s) on your system. During this time, you can select segments of the graph and bookmark them, giving them mnemonic names. This can be useful if you want to compare performance in one part of the run to another part of the run. Notice that once you select a block, it will give you the call tree breakdown for that selection only, and the relative performance of those calls. Once you feel you have collected enough information, you can click [Stop Profiling] to stop the application run and information collection and begin a more thorough analysis. Analyzing Method Timings So now that we’ve halted the run, we can look around the GUI and see what we can see. By default, the times are shown in terms of percentage of time of the total run of the application, though you can change it in the View menu item to milliseconds, ticks, or seconds as well. This won’t affect the percentages of methods, it only affects what units the times are shown. Notice also that the major hotspot seems to be in a method without source, ANTS Profiler will filter these out by default, but you can right-click on the line and remove the filter to see more detail. This proves especially handy when a bottleneck is due to a method in the BCL. So now that we’ve removed the filter, we see a bit more detail: In addition, ANTS Performance Profiler gives you the ability to decompile the methods without source so that you can dive even deeper, though typically this isn’t necessary for our purposes. When looking at timings, there are generally two types of timings for each method call: Time: This is the time spent ONLY in this method, not including calls this method makes to other methods. Time With Children: This is the total of time spent in both this method AND including calls this method makes to other methods. In other words, the Time tells you how much work is being done exclusively in this method, and the Time With Children tells you how much work is being done inclusively in this method and everything it calls. You can also choose to display the methods in a tree or in a grid. The tree view is the default and it shows the method calls arranged in terms of the tree representing all method calls and the parent method that called them, etc. This is useful for when you find a hot-spot method, you can see who is calling it to determine if the problem is the method itself, or if it is being called too many times. The grid method represents each method only once with its totals and is useful for quickly seeing what method is the trouble spot. In addition, you can choose to display Methods with source which are generally the methods you wrote (as opposed to native or BCL code), or Any Method which shows not only your methods, but also native calls, JIT overhead, synchronization waits, etc. So these are just two ways of viewing the same data, and you’re free to choose the organization that best suits what information you are after. Analyzing Method Source If we look at the timings above, we see that our AddToList() method (and in particular, it’s call to the List<T>.Sort() method in the BCL) is the hot-spot in this analysis. If ANTS sees a method that is consuming the most time, it will flag it as a hot-spot to help call out potential areas of concern. This doesn’t mean the other statistics aren’t meaningful, but that the hot-spot is most likely going to be your biggest bang-for-the-buck to concentrate on. So let’s select the AddToList() method, and see what it shows in the source window below: Notice the source breakout in the bottom pane when you select a method (from either tree or grid view). This shows you the timings in this method per line of code. This gives you a major indicator of where the trouble-spot in this method is. So in this case, we see that performing a Sort() on the List<T> after every Add() is killing our performance! Of course, this was a very contrived, duh moment, but you’d be surprised how many performance issues become duh moments. Note that this one line is taking up 86% of the execution time of this application! If we eliminate this bottleneck, we should see drastic improvement in the performance. So to fix this, if we still wanted to maintain the List<T> we’d have many options, including: delay Sort() until after all Add() methods, using a SortedSet, SortedList, or SortedDictionary depending on which is most appropriate, or forgoing the sorting all together and using a Dictionary. Rinse, Repeat! So let’s just change all instances of List<string> to SortedSet<string> and run this again through the profiler: Now we see the AddToList() method is no longer our hot-spot, but now the Max() and Min() calls are! This is good because we’ve eliminated one hot-spot and now we can try to correct this one as well. As before, we can then optimize this part of the code (possibly by taking advantage of the fact the list is now sorted and returning the first and last elements). We can then rinse and repeat this process until we have eliminated as many bottlenecks as possible. Calls by Web Request Another feature that was added recently is the ability to view .NET methods grouped by the HTTP requests that caused them to run. This can be helpful in determining which pages, web services, etc. are causing hot spots in your web applications. Summary If you like the other ANTS tools, you’ll like the ANTS Performance Profiler as well. It is extremely easy to use with very little product knowledge required to get up and running. There are profilers built into the higher product lines of Visual Studio, of course, which are also powerful and easy to use. But for quickly jumping in and finding hot spots rapidly, Red Gate’s Performance Profiler 7.4 is an excellent choice. Technorati Tags: Influencers,ANTS,Performance Profiler,Profiler

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  • Thread Synchronization and Synchronization Primitives

    When considering synchronization in an application, the decision truly depends on what the application and its worker threads are going to do. I would use synchronization if two or more threads could possibly manipulate the same instance of an object at the same time. An example of this in C# can be demonstrated through the use of storing data in a static object. A static object is initialized once per application and the data within the object can be accessed by all threads. I would use the synchronization primitives to prevent any data from being manipulated by multiple threads simultaneously. This would reduce any data corruption from occurring within the object. On the other hand if all the threads used non static objects and were independent of the other tasks there would be no need to use synchronization. Synchronization Primitives in C#: Basic Blocking Locking Signaling Non-Blocking Synchronization Constructs The Basic Blocking methods include Sleep, Join, and Task.Wait.  These methods force threads to wait until other threads have completed. In addition, these methods can also force a thread to wait a set amount of time before continuing to work.   The Locking primitive prevents a thread from entering a critical section of code while another thread is in the same critical section.  If another thread attempts to enter a locked code, it will wait, until the code block is released. The Signaling primitive allows a thread to temporarily pause work until receiving a notification from another thread that it is ok to continue working. The Signaling primitive removes the need for polling.The Non-Blocking Synchronization Constructs protect access to a common field by calling upon processor primitives.

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  • "Host key verification failed" error when transfering files using SCP command

    - by rvsi
    When I am trying to transfer files using SCP command I'm getting this error (Removed my IP and RSA key): @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY! Someone could be eavesdropping on you right now (man-in-the-middle attack)! It is also possible that the RSA host key has just been changed. The fingerprint for the RSA key sent by the remote host is ------------------------(RSA key) Please contact your system administrator. Add correct host key in /home/users/myaccount/.ssh/known_hosts to get rid of this message. Offending key in /home/users/myaccount/.ssh/known_hosts:4 RSA host key for 'my IP' has changed and you have requested strict checking. Host key verification failed. lost connection I am using newly installed Ubuntu 12.04 and I can connect to this server using ssh. Any help?

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  • Need help diagnosing network performance issues

    - by tokes
    I am currently working in a developing country as a system analyst for a government department. My area of expertise is software projects, but I've come across a few issues with the network setup in my office. (Unfortunately, being a developing country, there's not a lot of professional help available for this sort of thing.) Most recently, I am trying to diagnose a problem with slowness on the network. Our office is connected to the internet via an ADSL wireless modem/router (called Router). The modem is connected via ethernet to a switch (called Switch). The modem also acts as a wireless access point (called Wireless1), though because it is in a room at the end of the floor, it's range is limited. There are ethernet ports installed around the office. The cables of these all lead back to the same switch. In closer vicinity to the bulk of the client computers, there is another wireless router that acts as an access point for those clients (called Wireless2). That router is connected via ethernet to a wall port, and therefore to Switch. There is also a Windows server which acts as a DNS server (called DNSBox) which is located in the same room and is connected directly to Switch. ---Internet----------| Router/Wireless1 192.168.10.1 ---------------| |----|=========| DNSBox | |-------------------- 192.168.10.4 --------------------| Switch |---Other clients---- | |-------------------- |----|=========| Wireless2 ------------------| 192.168.10.198 One final thing to mention about the network setup. All clients are configured with manual IP addresses. Their router/gateway is set to the IP address of Router, and their DNS server is set to the IP address of DNSBox (with a secondary IP set to an external IP - that of our ISP's DNS server). Here are the symptoms we are experiencing: Clients connected to Wireless2 AP experience slow and unstable connections to the internet. (Slow here is defined as speeds of ~1KB/s, though ping response times seem to be as normal.) Clients connected via ethernet to Switch also experience the same slowness. Clients connected to Wireless1 AP (i.e. connecting via wireless directly to the ADSL modem) experience normal connections to the internet. Clients connected via ethernet to Router (i.e. connecting via ethernet directly to the ADSL modem) also experience normal connections to the internet. I also tried to gauge the connection performance between two machines on the network via ethernet: A file transfer between two clients who were both directly connected to Switch was the fastest; A file transfer between one client directly connected to Switch, and one client directly connected to Router (which is directly connected to Switch) performed much slower; A file transfer between two clients directly connected to Router also performed slowly. Things I have attempted to diagnose the problem: Restarted Switch -- no change. We tried unplugging ethernet jacks from Switch 4 at a time and testing the internet connection. The thought here was that perhaps a client on the network has contracted a virus, and is possibly spamming the network with traffic? (Not very technical, I know.) Unfortunately we couldn't get any significant increases in performance using this method. There were a couple of times when it seemed to be better, but then the connection speed quickly dropped back to slow/dead pace. I didn't want to unplug all jacks from Switch because I was concerned that users might be affected or that I would re-plug in the jacks incorrectly (should I even be worried about that? a port is a port on a switch, right?) I tried swapping the ethernet cable used to connect Router to Switch -- no change in performance. I tried swapping the port used on Switch for Router -- no change in performance. Anyone got any ideas on what this could be? Should I be mentioning specific brand names/models of the hardware used? Virii outbreaks are common in this country/office -- what could I be doing to figure out if a virus is at fault? If it is a virus, it doesn't seem to be generating a lot of traffic to/from the internet, because a) I can still get a good speed if I am directly connected to Router / Wireless1 and b) our ISP data usage has not risen suspiciously. Thanks for your help! Update #1 Here are the specs of some of the hardware: Switch is an Edimax ES3132RL 32-Port 10/100 Rackmount Switch Router is a D-Link DSL-G604T Update #2 I just tried unplugging everything except a laptop and Router from Switch. Speeds are still slow. I guess that means that Router / Switch are not being flooded? It seems more and more likely that the cause is something to do with the interaction between Router and Switch. However, I still can't find any useful resources on setting the LAN speed for either (and I'm not well-versed in these advanced networking configurations).

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  • ISA 2006 refuses VPN DHCP requests as spoofing

    - by Daniel
    I'm running ISA 2006 with PPTP VPN for my AD-controlled network. DHCP is located on the ISA server itself and authentication is done by RADIUS (NPS) located on the DC. Right now my VPN clients can connect, access local DNS, and can ping ISA, the DC, and other clients. Here's where it gets weird. I noticed that despite all this, ipconfig shows the following: PPP adapter North Horizon VPN: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : North Horizon VPN Physical Address. . . . . . . . . : DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes IPv4 Address. . . . . . . . . . . : 10.42.4.7(Preferred) Subnet Mask . . . . . . . . . . . : 255.255.255.255 Default Gateway . . . . . . . . . : 0.0.0.0 DNS Servers . . . . . . . . . . . : 10.42.1.10 NetBIOS over Tcpip. . . . . . . . : Enabled So I went over and checked my ISA logs for both DHCP requests and replies, only to find out that my VPN clients are being denied because ISA thinks its a spoof. Here's some relevant information from the log (the VPN subnet is 10.42.4.0/24): Client IP: 10.42.4.6 Destination: 255.255.255.255:67 Client Username: (blank) Protocol: DHCP (request) Action: Denied Connection Rule: (blank) Source Network: VPN Clients Destination Network: Local Host Result Code: 0xc0040014 FWX_E_FWE_SPOOFING_PACKET_DROPPED Network Interface: 10.42.4.11 --------------------------------------------------------- Original Client IP: 10.42.4.6 Destination: 10.42.1.1 Client Username: (valid user) Protocol: PING Action: Initiated Connection Rule: Allow PING to ISA Source Network: VPN Clients Destination Network: Local Host Result Code: 0x0 ERROR_SUCCESS Network Interface: (blank) I wasn't sure what this 10.42.4.11 network interface was - it certainly wasn't something I had setup - untill I saw it in Routing and Remote Access under IP Routing General as an interface called "Internal" bound to the same IP address. I also noticed that since ISA takes blocks of 10 IP addresses from DHCP for VPN, it had reserved 10.42.4.2-11. I'm not sure if it means anything, though. Thanks for your help.

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  • debian lenny xen bridge networking problem

    - by Sasha
    DomU isn't talking to the world, but it talks to Dom0. Here are the tests that I made: Dom0 (external networking is working): ping 188.40.96.238 #Which is Domu's ip PING 188.40.96.238 (188.40.96.238) 56(84) bytes of data. 64 bytes from 188.40.96.238: icmp_seq=1 ttl=64 time=0.092 ms DomU: ping 188.40.96.215 #Which is Dom0's ip PING 188.40.96.215 (188.40.96.215) 56(84) bytes of data. 64 bytes from 188.40.96.215: icmp_seq=1 ttl=64 time=0.045 ms ping 188.40.96.193 #Which is the gateway - fail PING 188.40.96.193 (188.40.96.193) 56(84) bytes of data. ^C --- 188.40.96.193 ping statistics --- 2 packets transmitted, 0 received, 100% packet loss, time 1013ms The system is debian lenny with a normal setup. Here is my configs: uname -a Linux green0 2.6.26-2-xen-686 #1 SMP Wed Aug 19 08:47:57 UTC 2009 i686 GNU/Linux cat /etc/xen/green1.cfg |grep -v '#' kernel = '/boot/vmlinuz-2.6.26-2-xen-686' ramdisk = '/boot/initrd.img-2.6.26-2-xen-686' memory = '2000' root = '/dev/xvda2 ro' disk = [ 'file:/home/xen/domains/green1/swap.img,xvda1,w', 'file:/home/xen/domains/green1/disk.img,xvda2,w', ] name = 'green1' vif = [ 'ip=188.40.96.238,mac=00:16:3E:1F:C4:CC' ] on_poweroff = 'destroy' on_reboot = 'restart' on_crash = 'restart' ifconfig eth0 Link encap:Ethernet HWaddr 00:24:21:ef:2f:86 inet addr:188.40.96.215 Bcast:188.40.96.255 Mask:255.255.255.192 inet6 addr: fe80::224:21ff:feef:2f86/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:3296 errors:0 dropped:0 overruns:0 frame:0 TX packets:2204 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:262717 (256.5 KiB) TX bytes:330465 (322.7 KiB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) peth0 Link encap:Ethernet HWaddr 00:24:21:ef:2f:86 inet6 addr: fe80::224:21ff:feef:2f86/64 Scope:Link UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1 RX packets:3407 errors:0 dropped:657431448 overruns:0 frame:0 TX packets:2291 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:319941 (312.4 KiB) TX bytes:338423 (330.4 KiB) Interrupt:16 Base address:0x8000 vif2.0 Link encap:Ethernet HWaddr fe:ff:ff:ff:ff:ff inet6 addr: fe80::fcff:ffff:feff:ffff/64 Scope:Link UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1 RX packets:27 errors:0 dropped:0 overruns:0 frame:0 TX packets:151 errors:0 dropped:33 overruns:0 carrier:0 collisions:0 txqueuelen:32 RX bytes:1164 (1.1 KiB) TX bytes:20974 (20.4 KiB) ip a s 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: peth0: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000 link/ether 00:24:21:ef:2f:86 brd ff:ff:ff:ff:ff:ff inet6 fe80::224:21ff:feef:2f86/64 scope link valid_lft forever preferred_lft forever 4: vif0.0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN link/ether fe:ff:ff:ff:ff:ff brd ff:ff:ff:ff:ff:ff 5: veth0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff 6: vif0.1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN link/ether fe:ff:ff:ff:ff:ff brd ff:ff:ff:ff:ff:ff 7: veth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff 8: vif0.2: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN link/ether fe:ff:ff:ff:ff:ff brd ff:ff:ff:ff:ff:ff 9: veth2: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff 10: vif0.3: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN link/ether fe:ff:ff:ff:ff:ff brd ff:ff:ff:ff:ff:ff 11: veth3: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff 12: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN link/ether 00:24:21:ef:2f:86 brd ff:ff:ff:ff:ff:ff inet 188.40.96.215/26 brd 188.40.96.255 scope global eth0 inet6 fe80::224:21ff:feef:2f86/64 scope link valid_lft forever preferred_lft forever 14: vif2.0: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 32 link/ether fe:ff:ff:ff:ff:ff brd ff:ff:ff:ff:ff:ff inet6 fe80::fcff:ffff:feff:ffff/64 scope link valid_lft forever preferred_lft forever brctl show bridge name bridge id STP enabled interfaces eth0 8000.002421ef2f86 no peth0 vif2.0 ip r l Dom0: 188.40.96.192/26 dev eth0 proto kernel scope link src 188.40.96.215 default via 188.40.96.193 dev eth0 DomU: 188.40.96.192/26 dev eth0 proto kernel scope link src 188.40.96.238 default via 188.40.96.193 dev eth0

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  • ifup eth0 failed in Ubuntu 11.10 and Ubuntu 10.04.3

    - by Ajay
    ifup eth0 failed to bring up eth0 First, I have set static ip using the below commands: Commands: ifdown eth0 ifconfig eth0 X.X.X.X netmask 255.255.252.0 up route add default gw X.X.X.X I was successful in setting up static ip X.X.X.X and I could see the same in the output of command "ifconfig". Now I am trying to revert network back to dhcp using the below commands: Commands: ifdown eth0 ifup eth0 Output : RTNETLINK answers: File exists ssh stop/waiting ssh start/running, process 1524 ifup eth0, failed to bring back dhcp. Contents of /etc/network/interfaces root@bdhcp396:~# cat /etc/network/interfaces # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto eth0 iface eth0 inet dhcp Is this a bug in Ubuntu 11.10/10.04.3? I see a similar bug raised - https://bugs.launchpad.net/ubuntu/+source/ifupdown/+bug/876829

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