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  • populatin jComBobox with data from a db tbl(table) column

    - by mnmyles
    Hi guyz? I have a JComboBox which i have named "venue_JCB" i want to load details from a tbl column on form load at the initcomponets() i have declared the method "accessDBinit() ;" and after the initComponets() i have implemented the accessDBinit(); method as follows: ================================code============================ void accessDBinit() //Get Student List in the List Box { try { sql = "SELECT classLevel FROM class_session ORDER BY classLevel"; java.lang.Class.forName("com.mysql.jdbc.Driver"); Connection con2=DriverManager.getConnection("jdbc:mysql:///coast","root",""); Statement stmt2 = (Statement)con2.createStatement(); boolean hasResults = stmt2.execute(sql); if(hasResults) { ResultSet rs2 = stmt2.getResultSet(); if(rs2!=null) { displayResultsinit(rs2); } db.stmt.close(); } } catch(Exception e) { System.out.println(e+"Error in connection"); } } void displayResultsinit(ResultSet r) throws SQLException { ResultSetMetaData rmeta = r.getMetaData(); int numColumns=rmeta.getColumnCount(); while(r.next()) { for(int i=1;i<=numColumns;++i) { if(i<=numColumns) { venue_JCB.addItem(r.getString(i)); } } } } ====================================end of code=================================== the method works (Populate the combobox) but at the output bar i get the following on form load and also whenever i select a component from the combobox ======= error===== java.lang.NullPointerExceptionError in connection could some one please tell me where i am going wrong with the method? Thanks in advance regards Malachi

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  • Implementing eval and load functions inside a scripting engine with Flex and Bison.

    - by Simone Margaritelli
    Hy guys, i'm developing a scripting engine with flex and bison and now i'm implementing the eval and load functions for this language. Just to give you an example, the syntax is like : import std.*; load( "some_script.hy" ); eval( "foo = 123;" ); println( foo ); So, in my lexer i've implemented the function : void hyb_parse_string( const char *str ){ extern int yyparse(void); YY_BUFFER_STATE prev, next; /* * Save current buffer. */ prev = YY_CURRENT_BUFFER; /* * yy_scan_string will call yy_switch_to_buffer. */ next = yy_scan_string( str ); /* * Do actual parsing (yyparse calls yylex). */ yyparse(); /* * Restore previous buffer. */ yy_switch_to_buffer(prev); } But it does not seem to work. Well, it does but when the string (loaded from a file or directly evaluated) is finished, i get a sigsegv : Program received signal SIGSEGV, Segmentation fault. 0xb7f2b801 in yylex () at src/lexer.cpp:1658 1658 if ( YY_CURRENT_BUFFER_LVALUE->yy_buffer_status == YY_BUFFER_NEW ) As you may notice, the sigsegv is generated by the flex/bison code, not mine ... any hints, or at least any example on how to implement those kind of functions? PS: I've succesfully implemented the include directive, but i need eval and load to work not at parsing time but execution time (kind of PHP's include/require directives).

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  • trackroll does not works as i want or expect to do,blackberry

    - by SWATI
    i am working on blackberry curve 8300 i have added some components in the main screen,now i want to move the focus vertically when the trackball moves up or down and move the focus horizontally when track-Wheel moves left or right. ================================================================================== --Title area that contains a focusable field(BACK)-- --Non focusable Label field that indicates the name of the user-- --A horizontal field manager1 that contains 4 buttons-- --A horizontal field manager2 that contains 4 buttons-- --A horizontal field manager2 that contains 4 buttons-- ================================================================================== now suppose currently focus is on BACK button and i scroll the track-wheel downwards then, focus should come on 1st button of manager1 Again when i scroll downwards,then focus should come on the 1st button of manager2 and not the 2nd button of manager1(as its happening on device) my code is ::: protected boolean trackwheelRoll(int amount, int status, int time) { focusIndex = this.getFieldWithFocusIndex(); System.out.println("focus index ::::::::::::::::"+focusIndex); Field f; if(focusIndex!=0) { if(amount==-1) { //move up if(focusIndex>=0) { focusIndex = focusIndex-1; f = getField(focusIndex); f.setFocus(); } } if(amount==1) { //moving down if(focusIndex<=3) { f = getField(++focusIndex); f.setFocus(); } } } return super.trackwheelRoll(amount, status, time); } even after this control moves abruptly on simulator but on device no change took place

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  • Get the key and value of Map that is used Inside another Map (JAVA)

    - by Umair Iqbal
    I am using a map inside another map, The key of the outer map is Integer and the value is another Map. I get the values as expected but I don't know how to get the key and value of teh inner map. Here is the code Map<Integer, Map<Integer, Integer>> cellsMap = new HashMap<Integer, Map<Integer, Integer>>(); Map<Integer , Integer> bandForCell = cellsMap.get(band_number); if (bandForCell == null) bandForCell = new HashMap<Integer, Integer>(); bandForCell.put(erfcn, cell_found); cellsMap.put(band_number, bandForCell); csv.writeCells((Map<Integer, Map<Integer, Integer>>) cellsMap); public void writeCells (Map<Integer, Map<Integer, Integer>> cellsMap ) throws IOException { for (Map.Entry<Integer, Map<Integer, Integer>> entry : cellsMap.entrySet()) { System.out.println("Key: " + entry.getKey() + ". Value: " + entry.getValue() + "\n"); } } Out put of my Map Key: 20 Value: {6331=0, 6330=1, 6329=1, 6328=0, 6335=1, 6437=0, 6436=1} The value in the above output is another map. How can I get the key and value of the inner map from the value of the outer map? Like Keys of inner map = 6331, 6330, 6329 .... and values of inner map = 0 , 1 , 1 , 0 ... Thanks

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  • Problem with setVisible (true)

    - by Jessy
    The two examples shown below are same. Both are supposed to produce same result e.g. generate the coordinates of images displayed on JPanel. Example 1, works perfectly (print the coordinates of images), however example 2 returning 0 for the coordinate. I was wondering why because, I have put the setvisible (true) after adding the panel, in both examples. The only difference is that example 1 used extends JPanel and example 2 extends JFrame EXAMPLE 1: public class Grid extends JPanel{ public static void main(String[] args){ JFrame jf=new JFrame(); jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); final Grid grid = new Grid(); jf.add(grid); jf.pack(); Component[] components = grid.getComponents(); for (Component component : components) { System.out.println("Coordinate: "+ component.getBounds()); } jf.setVisible(true); } } EXAMPLE 2: public class Grid extends JFrame { public Grid () { setLayout(new GridBagLayout()); GridBagLayout m = new GridBagLayout(); Container c = getContentPane(); c.setLayout (m); GridBagConstraints con = new GridBagConstraints(); //construct the JPanel pDraw = new JPanel(); ... m.setConstraints(pDraw, con); pDraw.add (new GetCoordinate ()); // call new class to generate the coordinate c.add(pDraw); pack(); setVisible(true); } public static void main(String[] args) { new Grid(); } }

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  • I am confused -- Will this code always work?

    - by Shekhar
    Hello, I have written this piece of code public class Test{ public static void main(String[] args) { List<Integer> list = new ArrayList<Integer>(); for(int i = 1;i<= 4;i++){ new Thread(new TestTask(i, list)).start(); } while(list.size() != 4){ // this while loop required so that all threads complete their work } System.out.println("List "+list); } } class TestTask implements Runnable{ private int sequence; private List<Integer> list; public TestTask(int sequence, List<Integer> list) { this.sequence = sequence; this.list = list; } @Override public void run() { list.add(sequence); } } This code works and prints all the four elements of list on my machine. My question is that will this code always work. I think there might be a issue in this code when two/or more threads add element to this list at the same point. In that case it while loop will never end and code will fail. Can anybody suggest a better way to do this? I am not very good at multithreading and don't know which concurrent collection i can use? Thanks Shekhar

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  • URI scheme is not "file"

    - by Ankur
    I get the exception: "URI scheme is not file" The url I am playing with is ... and it very much is a file http://local.wasp.uwa.edu.au/~pbourke/miscellaneous/domefisheye/ladybug/fish4.jpg What I am doing is trying to get the name of a file and then save that file (from another server) onto my computer/server from within a servlet. I have a String called "url", from thereon here is my code: url = Streams.asString(stream); //gets the URL from a form on a webpage System.out.println("This is the URL: "+url); URI fileUri = new URI(url); File fileFromUri = new File(fileUri); onlyFile = fileFromUri.getName(); URL fileUrl = new URL(url); InputStream imageStream = fileUrl.openStream(); String fileLoc2 = getServletContext().getRealPath("pics/"+onlyFile); File newFolder = new File(getServletContext().getRealPath("pics")); if(!newFolder.exists()){ newFolder.mkdir(); } IOUtils.copy(imageStream, new FileOutputStream("pics/"+onlyFile)); } The line causing the error is this one: File fileFromUri = new File(fileUri); I have added the rest of the code so you can see what I am trying to do.

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  • Sending JSON to a server

    - by SK9
    I'm running the following Java, an HttpURLConnection PUT request with JSON data that will be sent from an Android device. I'll handle any raised exceptions after this is working. Authenticator.setDefault(new Authenticator() { protected PasswordAuthentication getPasswordAuthentication() { return new PasswordAuthentication(nameString, pwdString.toCharArray()); } }); url = new URL(myURLString); HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection(); urlConnection.setDoOutput(true); urlConnection.setChunkedStreamingMode(0); urlConnection.setRequestMethod("PUT"); urlConnection.setRequestProperty("Content-Type", "application/json"); OutputStream output = null; try { output = urlConnection.getOutputStream(); output.write(jsonArray.toString().getBytes()); } finally { if (output != null) { output.close(); } } int status = ((HttpURLConnection) urlConnection).getResponseCode(); System.out.println("" + status); urlConnection.disconnect(); I'm receiving an HTTP 500 error (internal error code), that an unexpected property is blocking the request. The JSONArray comprises JSONObjects whose keys I know are correct. The server is pretty standard, and expects HTTP PUTs with JSON bodies. Am I missing something glaring? Thanking you kindly in advance.

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  • Read Java in as Hex

    - by James
    Hi, I have tried to solve this but I keep coming up with stuff that is no help I'm sure this is easy (when you know how of course ;) ) What I would like to do is read in a file using a byte stream like below: while((read = in.read()) != -1){ //code removed to save space Integer.toHexString(read); System.out.println(read); } When it prints out the Hex to the screen it will print out numbers fine e.g 31 13 12 0 but when it comes to a hex code that should be 01 31 it will print 0 131. I want to read it in to a variable like you would see in a hex editor i.e 00 11 21 31 no single numbers as i need to scan the whole file and look for patterns which I know how to do I'm just stuck on this :/ so in short i need a variabe to contain the two hex characters i.e int temp = 01 not int temp = 0 , I hope this all makes sense, I'm a little confused as it's 3am! If anyone knows how to do this I would be most greatful, p.s thanks for the help in advance this site has saved me loads of research and have learnt a lot! Many thanks.

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  • Why is my GUI unresponsive while a SwingWorker thread runs?

    - by Starchy
    Hello, I have a SwingWorker thread with an IOBound task which is totally locking up the interface while it runs. Swapping out the normal workload for a counter loop has the same result. The SwingWorker looks basically like this: public class BackupWorker extends SwingWorker<String, String> { private static String uname = null; private static String pass = null; private static String filename = null; static String status = null; BackupWorker (String uname, String pass, String filename) { this.uname = uname; this.pass = pass; this.filename = filename; } @Override protected String doInBackground() throws Exception { BackupObject bak = newBackupObject(uname,pass,filename); return "Done!"; } } The code that kicks it off lives in a class that extends JFrame: public void actionPerformed(ActionEvent event) { String cmd = event.getActionCommand(); if (BACKUP.equals(cmd)) { SwingUtilities.invokeLater(new Runnable() { public void run() { final StatusFrame statusFrame = new StatusFrame(); statusFrame.setVisible(true); SwingUtilities.invokeLater(new Runnable() { public void run () { statusFrame.beginBackup(uname,pass,filename); } }); } }); } } Here's the interesting part of StatusFrame: public void beginBackup(final String uname, final String pass, final String filename) { worker = new BackupWorker(uname, pass, filename); worker.execute(); try { System.out.println(worker.get()); } catch (InterruptedException e) { e.printStackTrace(); } catch (ExecutionException e) { e.printStackTrace(); } } } So far as I can see, everything "long-running" is handled by the worker, and everything that touches the GUI on the EDT. Have I tangled things up somewhere, or am I expecting too much of SwingWorker?

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  • Blackberry app stuck trying to access a server.

    - by Tejaswi Yerukalapudi
    Hi, I've built a ASP.NET webservice and I'm trying to access it from a Blackberry. I've been testing it out with multiple devices and the simulator and it works fine, but there's just the one Blackberry 9000 (It's not the model, I've tried it out with another Blackberry 9000), and it's stuck waiting for a response from the server. Relevant section of the code that accesses this - System.out.println("IN ntwk access thread, start point"); HttpConnection connection = (HttpConnection)Connector.open(serviceURL + WSNAME); connection.setRequestMethod(HttpConnection.POST); connection.setRequestProperty("Content-type", "application/x-www-form-urlencoded"); connection.setRequestProperty("Content-length", Integer.toString(postData1.length)); OutputStream requestOutput = connection.openOutputStream(); requestOutput.write(postData1); requestOutput.close(); final int responseCode = connection.getResponseCode(); if(responseCode!= HttpConnection.HTTP_OK) { //Process the error condition } // Request succeeded process the data. It seems to be getting stuck after connection.getResponseCode(). Is there some way I can verify what's going wrong with this particular device? Thanks, Teja

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  • Java Binary Tree. Priting InOrder traversal

    - by user69514
    I am having some problems printing an inOrder traversal of my binary tree. Even after inserting many items into the tree it's only printing 3 items. public class BinaryTree { private TreeNode root; private int size; public BinaryTree(){ this.size = 0; } public boolean insert(TreeNode node){ if( root == null) root = node; else{ TreeNode parent = null; TreeNode current = root; while( current != null){ if( node.getData().getValue().compareTo(current.getData().getValue()) <0){ parent = current; current = current.getLeft(); } else if( node.getData().getValue().compareTo(current.getData().getValue()) >0){ parent = current; current = current.getRight(); } else return false; if(node.getData().getValue().compareTo(parent.getData().getValue()) < 0) parent.setLeft(node); else parent.setRight(node); } } size++; return true; } /** * */ public void inOrder(){ inOrder(root); } private void inOrder(TreeNode root){ if( root.getLeft() !=null) this.inOrder(root.getLeft()); System.out.println(root.getData().getValue()); if( root.getRight() != null) this.inOrder(root.getRight()); } }

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  • How to get application context path in spring-ws?

    - by Dhaliwal
    I am using Spring-WS to create a webservice. In my project, I have created a Helper class to reads sample response and request xml file which are located in my /src/main/resource folder. When I am unit-testing my webservice application 'locally', I use the System.getProperty("user.dir") to get the application context folder. The following is a method that I created in the Helper class to help me retrieve the file that I am interested in my resource folder. public static File getFileFromResources(String filename) { System.out.println("Getting file from resource folder"); File request = null; String curDir = System.getProperty("user.dir"); String contextpath = "C:\\src\\main\\resources\\"; request = new File(curDir + contextpath + filename); return request; } However, after 'publishing' the compiled WAR file to the ../webapps folder to the Apache Tomcat directory, I realise that System.getProperty("user.dir") no longer returns my application context path. Instead, it is returning the Apache Tomcat root directory as shown C:\Program Files\Apache Software Foundation\Tomcat 6.0\src\main\resources\SampleClientFile I cant seem to find any information about getting the root folder of my webservice. I have seen examples on Spring web application where I can retrieve the context path by using the following : request.getSession().getServletContext().getContextPath() But in this case, I am using a Spring web application where there is a servlet context in the request. But the Spring-WS, my entry point is an endpoint. How can I get the context path of my webservice application. I am expecting a context path of something like C:\Program Files\Apache Software Foundation\Tomcat 6.0\webapps\clientWebService\WEB-INF\classes Could someone suggest a way to achieve this?

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  • How can I improve the performance of this double-for print?

    - by Florenc
    I have the following static method that prints the data imported from a 40.000 lines .xls spreadsheet. Now, it takes about 27 seconds to print the data in the console and the memory consumption is huge. import org.apache.poi.hssf.usermodel.*; import org.apache.poi.ss.usermodel.*; public static void printSheetData(List<List<HSSFCell>> sheetData) { for (int i = 0; i < sheetData.size(); i++) { List<HSSFCell> list = (List<HSSFCell>) sheetData.get(i); for (int j = 0; j < list.size(); j++) { HSSFCell cell = (HSSFCell) list.get(j); System.out.print(cell.toString()); if (j < list.size() - 1) { System.out.print(", "); } } System.out.println(""); } } Disclaimer: I know, I know large data belong to a database, don't print output in the console, premature optimization is the root of all evils...

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  • (outofmemoryerror: java heap space) when iterating through oracle records...

    - by rockit
    hello fellow java developers. I'm having a bit of an issue here. I have code that gets a resultset from an oracle database, prints each row to a file, then gets the next row - and continues till the end of the resultset. Only this isn't what happens. What happens is that it gets the resultset, starts iterating through the rows, printing to file as it goes, until it runs out of memory - claiming it needs more space on the java heap. The app is currently running with 2g of memory on the heap and the code breaks at about the 150000th row. I'm using jodbc6.jar and java 6 Here is an idea of what my code is doing: Connection conn = DriverManager.getConnection(url,"name","pwd"); conn.setAutoCommit(false); Statement stmt = conn.createStatement(); ResultSet rset = stmt.executeQuery(strSql); String strVar_1 = null; long lCount = 0; while(rset.next()){ lCount++; if (lCount % 100000 == 0){ System.out.println(lCount + " rows completed"); } strVar_1 = rset.getString("StringID"); /// breaks here!!!!!!!!! if (strVar_1 == null){ strVar_1 = ""; } if (!strQuery_1.equals("")){ out.write(strVar_1 + "\n"); } } out.close();

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  • Change classloader

    - by Chris
    I'm trying to switch the class loader at runtime: public class Test { public static void main(String[] args) throws Exception { final InjectingClassLoader classLoader = new InjectingClassLoader(); Thread.currentThread().setContextClassLoader(classLoader); Thread thread = new Thread("test") { public void run() { System.out.println("running..."); // approach 1 ClassLoader cl = TestProxy.class.getClassLoader(); try { Class c = classLoader.loadClass("classloader.TestProxy"); Object o = c.newInstance(); c.getMethod("test", new Class[] {}).invoke(o); } catch (Exception e) { e.printStackTrace(); } // approach 2 new TestProxy().test(); }; }; thread.setContextClassLoader(classLoader); thread.start(); } } and: public class TestProxy { public void test() { ClassLoader tcl = Thread.currentThread().getContextClassLoader(); ClassLoader ccl = ClassToLoad.class.getClassLoader(); ClassToLoad classToLoad = new ClassToLoad(); } } (it is not relevant what the InjectingClassLoader is) I'd like to make the result of "approach 1" and "approach 2" exactly same, but it looks like thread.setContextClassLoader(classLoader) does nothing and the "approach 2" always uses the system classloader (can be determined by comparing tcl and ccl variables while debugging). Is it possible to make all classes loaded by new thread use given classloader?

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  • Java KeyListener in separate class

    - by Chris
    So I have my main class here, where basically creates a new jframe and adds a world object to it. The world object is basically where all drawing and keylistening would take place... public class Blobs extends JFrame{ public Blobs() { super("Blobs :) - By Chris Tanaka"); setVisible(true); setResizable(false); setSize(1000, 1000); setIgnoreRepaint(true); setDefaultCloseOperation(EXIT_ON_CLOSE); add(new World()); } public static void main(String[] args) { new Blobs(); } } How exactly would you get key input from the world class? (So far I have my world class extending a jpanel and implementing a keylistener. In the constructor i addKeyListener(this). I also have these methods since they are auto implemented: public void keyPressed(KeyEvent e) { if (e.getKeyCode() == KeyEvent.VK_W) System.out.println("Hi"); } public void keyReleased(KeyEvent e) {} public void keyTyped(KeyEvent e) {} However this does not seem to work?

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  • Problem with relative file path

    - by Richard Knop
    So here is my program, which works ok: import java.io.FileReader; import java.io.BufferedReader; import java.io.IOException; import java.util.Scanner; import java.util.Locale; public class ScanSum { public static void main(String[] args) throws IOException { Scanner s = null; double sum = 0; try { s = new Scanner(new BufferedReader(new FileReader("D:/java-projects/HelloWorld/bin/usnumbers.txt"))); s.useLocale(Locale.US); while (s.hasNext()) { if (s.hasNextDouble()) { sum += s.nextDouble(); } else { s.next(); } } } finally { s.close(); } System.out.println(sum); } } As you can see, I am using absolute path to the file I am reading from: s = new Scanner(new BufferedReader(new FileReader("D:/java-projects/HelloWorld/bin/usnumbers.txt"))); The problem arises when I try to use the relative path: s = new Scanner(new BufferedReader(new FileReader("usnumbers.txt"))); I get an error: Exception in thread "main" java.lang.NullPointerException at ScanSum.main(ScanSum.java:24) The file usnumbers.txt is in the same directory as the ScanSum.class file: D:/java-projects/HelloWorld/bin/ScanSum.class D:/java-projects/HelloWorld/bin/usnumbers.txt How could I solve this?

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  • Improving my first Clojure program

    - by StackedCrooked
    After a few weekends exploring Clojure I came up with this program. It allows you to move a little rectangle in a window. Here's the code: (import java.awt.Color) (import java.awt.Dimension) (import java.awt.event.KeyListener) (import javax.swing.JFrame) (import javax.swing.JPanel) (def x (ref 0)) (def y (ref 0)) (def panel (proxy [JPanel KeyListener] [] (getPreferredSize [] (Dimension. 100 100)) (keyPressed [e] (let [keyCode (.getKeyCode e)] (if (== 37 keyCode) (dosync (alter x dec)) (if (== 38 keyCode) (dosync (alter y dec)) (if (== 39 keyCode) (dosync (alter x inc)) (if (== 40 keyCode) (dosync (alter y inc)) (println keyCode))))))) (keyReleased [e]) (keyTyped [e]))) (doto panel (.setFocusable true) (.addKeyListener panel)) (def frame (JFrame. "Test")) (doto frame (.add panel) (.pack) (.setDefaultCloseOperation JFrame/EXIT_ON_CLOSE) (.setVisible true)) (defn drawRectangle [p] (doto (.getGraphics p) (.setColor (java.awt.Color/WHITE)) (.fillRect 0 0 100 100) (.setColor (java.awt.Color/BLUE)) (.fillRect (* 10 (deref x)) (* 10 (deref y)) 10 10))) (loop [] (drawRectangle panel) (Thread/sleep 10) (recur)) Despite being an experienced C++ programmer I found it very challenging to write even a simple application in a language that uses a radically different style than what I'm used to. On top of that, this code probably sucks. I suspect the globalness of the various values is a bad thing. It's also not clear to me if it's appropriate to use references here for the x and y values. Any hints for improving this code are welcome.

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  • Finding Palindromes in an Array

    - by Jack L.
    For this assignemnt, I think that I got it right, but when I submit it online, it doesn't list it as correct even though I checked with Eclipse. The prompt: Write a method isPalindrome that accepts an array of Strings as its argument and returns true if that array is a palindrome (if it reads the same forwards as backwards) and /false if not. For example, the array {"alpha", "beta", "gamma", "delta", "gamma", "beta", "alpha"} is a palindrome, so passing that array to your method would return true. Arrays with zero or one element are considered to be palindromes. My code: public static void main(String[] args) { String[] input = new String[6]; //{"aay", "bee", "cee", "cee", "bee", "aay"} Should return true input[0] = "aay"; input[1] = "bee"; input[2] = "cee"; input[3] = "cee"; input[4] = "bee"; input[5] = "aay"; System.out.println(isPalindrome(input)); } public static boolean isPalindrome(String[] input) { for (int i=0; i<input.length; i++) { // Checks each element if (input[i] != input[input.length-1-i]){ return false; // If a single instance of non-symmetry } } return true; // If symmetrical, only one element, or zero elements } As an example, {"aay", "bee", "cee", "cee", "bee", "aay"} returns true in Eclipse, but Practice-It! says it returns false. What is going on?

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  • Why does resolveBinding() return null even though I setResolveBindings(true) on my ASTParser?

    - by Woody Zenfell III
    I am writing an Eclipse plug-in that uses JDT AST's ASTParser to parse a method. I am looking within that method for the creation of a particular type of object. When I find a ClassInstanceCreation, I call getType() on it to see what type is being instantiated. I want to be sure that the fully-resolved type being dealt with there is the one I think it is, so I tell the resultant Type object to resolveBinding(). I get null back even though there are no compilation errors and even though I called setResolveBindings(true) on my ASTParser. I gave my ASTParser (via setSource()) the ICompilationUnit that contains my method, so the parser has access to the entire workspace context. final IMethod method = ...; final ASTParser parser = ASTParser.newParser(AST.JLS3); parser.setResolveBindings(true); parser.setSource(method.getCompilationUnit()); parser.setSourceRange(method.getSourceRange().getOffset(), method.getSourceRange().getLength()); parser.setKind(ASTParser.K_CLASS_BODY_DECLARATIONS); final TypeDeclaration astRoot = (TypeDeclaration) parser.createAST(null); final ClassInstanceCreation classInstanceCreation = walkAstAndFindMyExpression(astRoot); final Type instantiatedType = classInstanceCreation.getType(); System.out.println("BINDING: " + instantiatedType.resolveBinding()); Why does resolveBinding() return null? How can I get the binding information?

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  • Class initialization and synchronized class method

    - by nybon
    Hi there, In my application, there is a class like below: public class Client { public synchronized static print() { System.out.println("hello"); } static { doSomething(); // which will take some time to complete } } This class will be used in a multi thread environment, many threads may call the Client.print() method simultaneously. I wonder if there is any chance that thread-1 triggers the class initialization, and before the class initialization complete, thread-2 enters into print method and print out the "hello" string? I see this behavior in a production system (64 bit JVM + Windows 2008R2), however, I cannot reproduce this behavior with a simple program in any environments. In Java language spec, section 12.4.1 (http://java.sun.com/docs/books/jls/second_edition/html/execution.doc.html), it says: A class or interface type T will be initialized immediately before the first occurrence of any one of the following: T is a class and an instance of T is created. T is a class and a static method declared by T is invoked. A static field declared by T is assigned. A static field declared by T is used and the reference to the field is not a compile-time constant (§15.28). References to compile-time constants must be resolved at compile time to a copy of the compile-time constant value, so uses of such a field never cause initialization. According to this paragraph, the class initialization will take place before the invocation of the static method, however, it is not clear if the class initialization need to be completed before the invocation of the static method. JVM should mandate the completion of class initialization before entering its static method according to my intuition, and some of my experiment supports my guess. However, I did see the opposite behavior in another environment. Can someone shed me some light on this? Any help is appreciated, thanks.

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  • Events still not showing up despite the many tries...sigh

    - by sheng88
    I have tried the recommendation from this forum and through the many google searches...but i still can't get the events to show up on my calendar via jsp....i tried with php and it worked...sigh...i wonder where is the error....sigh.... The processRequest method is fine but when it dispatches to the JSP page...nothing appears from the browser.... protected void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String email=request.getParameter("email"); try { ArrayList<CalendarEvt> calc=CalendarDAO.retrieveEvent(email); for (CalendarEvt calendarEvt : calc) { System.out.println(calendarEvt.getEventId()); } request.setAttribute("calendar", calc); request.getRequestDispatcher("calendar.jsp").forward(request, response); } catch (Exception e) { } } Here is the JSP section that's giving me headaches...(Without the loop...the Google link does appear...)...I have tried putting quotations and leaving them out....still no luck: <%--Load user's calendar--%> <script type='text/javascript'> $(document).ready(function() { var date = new Date(); var d = date.getDate(); var m = date.getMonth(); var y = date.getFullYear(); $('#calendar').fullCalendar({ editable: false, events: [ <c:forEach items="calendar" var="calc"> { title: '${calc.eventName}', start: ${calc.eventStart} }, </c:forEach> { title: 'Click for Google', start: new Date(y, m, 1), end: new Date(y, m, 1), url: 'http://google.com/' } ]//end of events }); }); </script> <%--Load user's calendar--%> ...any kind of help would be greatly appreciated...thx!!

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  • how to generate unique numbers less than 8 characters long.

    - by loudiyimo
    hi I want to generate unique id's everytime i call methode generateCustumerId(). The generated id must be 8 characters long or less than 8 characters. This requirement is necessary because I need to store it in a data file and schema is determined to be 8 characters long for this id. Option 1 works fine. Instead of option 1, I want to use UUID. The problem is that UUID generates an id which has to many characters. Does someone know how to generate a unique id which is less then 99999999? option 1 import java.util.HashSet; import java.util.Random; import java.util.Set; public class CustomerIdGenerator { private static Set<String> customerIds = new HashSet<String>(); private static Random random = new Random(); // XXX: replace with java.util.UUID public static String generateCustumerId() { String customerId = null; while (customerId == null || customerIds.contains(customerId)) { customerId = String.valueOf(random.nextInt(89999999) + 10000000); } customerIds.add(customerId); return customerId; } } option2 generates an unique id which is too long public static String generateCustumerId() { String ownerId = UUID.randomUUID().toString(); System.out.println("ownerId " + ownerId); return ownerId }

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  • Scala and Java BigDecimal

    - by geejay
    I want to switch from Java to a scripting language for the Math based modules in my app. This is due to the readability, and functional limitations of mathy Java. For e.g, in Java I have this: BigDecimal x = new BigDecimal("1.1"); BigDecimal y = new BigDecimal("1.1"); BigDecimal z = x.multiply(y.exp(new BigDecimal("2")); As you can see, without BigDecimal operator overloading, simple formulas get complicated real quick. With doubles, this looks fine, but I need the precision. I was hoping in Scala I could do this: var x = 1.1; var y = 0.1; print(x + y); And by default I would get decimal-like behaviour, alas Scala doesn't use decimal calculation by default. Then I do this in Scala: var x = BigDecimal(1.1); var y = BigDecimal(0.1); println(x + y); And I still get an imprecise result. Is there something I am not doing right in Scala? Maybe I should use Groovy to maximise readability (it uses decimals by default)?

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