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  • Problem in suspending 2 threads at the same time in MFC!

    - by kiddo
    I am learning about threading and multithreading..so i just created a small application in which i will update the progressbar and a static text using threading.I vl get two inputs from the user, start and end values for how long the loop should rotate.I have 2threads in my application. Thread1- to update the progressbar(according to the loop) the static text which will show the count(loop count). Thread2 - to update the another static text which will just diplay a name Basically if the user clicks start, the progressbar steps up and at the same time filecount and the name are displayed parallely. There's is another operation where if the user clicks pause it(thread) has to suspend until the user clicks resume. The problem is,the above will not work(will not suspend and resume) for both thread..but works for a singlw thread. Please check the code to get an idea and reply me what can done! on button click start void CThreadingEx3Dlg::OnBnClickedStart() { m_ProgressBar.SetRange(start,end); myThread1 = AfxBeginThread((AFX_THREADPROC)MyThreadFunction1,this); myThread2 = AfxBeginThread((AFX_THREADPROC)MyThreadFunction2,this); } thread1 UINT MyThreadFunction1(LPARAM lparam) { CThreadingEx3Dlg* pthis = (CThreadingEx3Dlg*)lparam; for(int intvalue =pthis->start;intvalue<=pthis->end; ++intvalue) { pthis->SendMessage(WM_MY_THREAD_MESSAGE1,intvalue); } return 0; } thread1 function LRESULT CThreadingEx3Dlg::OnThreadMessage1(WPARAM wparam,LPARAM lparam) { int nProgress= (int)wparam; m_ProgressBar.SetPos(nProgress); CString strStatus; strStatus.Format(L"Thread1:Processing item: %d", nProgress); m_Static.SetWindowText(strStatus); Sleep(100); return 0; } thread2 UINT MyThreadFunction2(LPARAM lparam) { CThreadingEx3Dlg* pthis = (CThreadingEx3Dlg*)lparam; for(int i =pthis->start;i<=pthis->end;i++) { pthis->SendMessage(WM_MY_THREAD_MESSAGE2,i); } return 0; } thread2 function LRESULT CThreadingEx3Dlg::OnThreadMessage2(WPARAM wparam,LPARAM lparam) { m_Static1.GetDlgItem(IDC_STATIC6); m_Static1.SetWindowTextW(L"Thread2 Running"); Sleep(100); m_Static1.SetWindowTextW(L""); Sleep(100); return TRUE; } void CThreadingEx3Dlg::OnBnClickedPause() { // TODO: Add your control notification handler code here if(!m_Track) { m_Track = TRUE; GetDlgItem(IDCANCEL)->SetWindowTextW(L"Resume"); myThread1->SuspendThread(); WaitForSingleObject(myThread1->m_hThread,INFINITE); myThread2->SuspendThread(); m_Static.SetWindowTextW(L"Paused.."); } else { m_Track = FALSE; GetDlgItem(IDCANCEL)->SetWindowTextW(L"Pause"); myThread1->ResumeThread(); myThread2->ResumeThread(); /*myEventHandler.SetEvent(); WaitForSingleObject(myThread1->m_hThread,INFINITE);*/ } }

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  • Best approach for using Scanner Objects in Java?

    - by devjeetroy
    Although I'm more of a C++/ASM guy, I have to work with java as a part of my undergrad course at college. Our teacher taught us input using Scanner(System.in), and told us that if multiple functions are were taking user input, it would be advisable that a single Scanner object is passed around so as to reduce chances of the input stream getting screwed up. Now using this approach has gotten me into a situation where I'm trying to use a Scanner.nextLine(), and this statement does not wait for user input. It just moves on to the following statement. I figured there may be some residual cr/lf or other characters in the Scanner that might not have been retrieved are causing the problem. Here is the code. while(lineScanner.hasNext()) { if(isPlaceHolder(temp = lineScanner.next())) { temp = temp.replace("<",""); temp = temp.replace(">", ""); System.out.print("Enter "+aOrA(temp.charAt(0)) +" " +temp + " : "); temp = consoleInput.nextLine(); } outputFileStream.print(temp + " "); } All of the code is inside a function which receives a Scanner object consoleInput. Ok, so what happens when i run it is that when the program enters the if() the first time, It carries out theSystem.out.print, does not wait for user input, and moves on to the second time that it enters the 'if' block. This time, it takes the input and the rest of the program operates normally. What is even more surprising is that when i check the output file created by the program, it is perfect, just as i want to be. Almost as if the first time input using the scanner is correct. I have solved this problem by creating a new system.in Scanner in the function itself, instead of receiving the Scanner object as a parameter. But I am still very curious to know what the hell is happening and why it couldn't be solved using a simple Scanner.reset(). Would it be better to just simply create a Scanner Object for each function? Thanks, Devjeet PS. Although I know how to take input using fileinputstreams and the like, we are not supposed to use it with the homework.

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  • C# MultiThread Safe Class Design

    - by Robert
    I'm trying to designing a class and I'm having issues with accessing some of the nested fields and I have some concerns with how multithread safe the whole design is. I would like to know if anyone has a better idea of how this should be designed or if any changes that should be made? using System; using System.Collections; namespace SystemClass { public class Program { static void Main(string[] args) { System system = new System(); //Seems like an awkward way to access all the members dynamic deviceInstance = (((DeviceType)((DeviceGroup)system.deviceGroups[0]).deviceTypes[0]).deviceInstances[0]); Boolean checkLocked = deviceInstance.locked; //Seems like this method for accessing fields might have problems with multithreading foreach (DeviceGroup dg in system.deviceGroups) { foreach (DeviceType dt in dg.deviceTypes) { foreach (dynamic di in dt.deviceInstances) { checkLocked = di.locked; } } } } } public class System { public ArrayList deviceGroups = new ArrayList(); public System() { //API called to get names of all the DeviceGroups deviceGroups.Add(new DeviceGroup("Motherboard")); } } public class DeviceGroup { public ArrayList deviceTypes = new ArrayList(); public DeviceGroup() {} public DeviceGroup(string deviceGroupName) { //API called to get names of all the Devicetypes deviceTypes.Add(new DeviceType("Keyboard")); deviceTypes.Add(new DeviceType("Mouse")); } } public class DeviceType { public ArrayList deviceInstances = new ArrayList(); public bool deviceConnected; public DeviceType() {} public DeviceType(string DeviceType) { //API called to get hardwareIDs of all the device instances deviceInstances.Add(new Mouse("0001")); deviceInstances.Add(new Keyboard("0003")); deviceInstances.Add(new Keyboard("0004")); //Start thread CheckConnection that updates deviceConnected periodically } public void CheckConnection() { //API call to check connection and returns true this.deviceConnected = true; } } public class Keyboard { public string hardwareAddress; public bool keypress; public bool deviceConnected; public Keyboard() {} public Keyboard(string hardwareAddress) { this.hardwareAddress = hardwareAddress; //Start thread to update deviceConnected periodically } public void CheckKeyPress() { //if API returns true this.keypress = true; } } public class Mouse { public string hardwareAddress; public bool click; public Mouse() {} public Mouse(string hardwareAddress) { this.hardwareAddress = hardwareAddress; } public void CheckClick() { //if API returns true this.click = true; } } }

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  • All possible combinations of length 8 in a 2d array

    - by CodeJunki
    Hi, I've been trying to solve a problem in combinations. I have a matrix 6X6 i'm trying to find all combinations of length 8 in the matrix. I have to move from neighbor to neighbor form each row,column position and i wrote a recursive program which generates the combination but the problem is it generates a lot of duplicates as well and hence is inefficient. I would like to know how could i eliminate calculating duplicates and save time. int a={{1,2,3,4,5,6}, {8,9,1,2,3,4}, {5,6,7,8,9,1}, {2,3,4,5,6,7}, {8,9,1,2,3,4}, {5,6,7,8,9,1}, } void genSeq(int row,int col,int length,int combi) { if(length==8) { printf("%d\n",combi); return; } combi = (combi * 10) + a[row][col]; if((row-1)>=0) genSeq(row-1,col,length+1,combi); if((col-1)>=0) genSeq(row,col-1,length+1,combi); if((row+1)<6) genSeq(row+1,col,length+1,combi); if((col+1)<6) genSeq(row,col+1,length+1,combi); if((row+1)<6&&(col+1)<6) genSeq(row+1,col+1,length+1,combi); if((row-1)>=0&&(col+1)<6) genSeq(row-1,col+1,length+1,combi); if((row+1)<6&&(row-1)>=0) genSeq(row+1,col-1,length+1,combi); if((row-1)>=0&&(col-1)>=0) genSeq(row-1,col-1,length+1,combi); } I was also thinking of writing a dynamic program basically recursion with memorization. Is it a better choice?? if yes than I'm not clear how to implement it in recursion. Have i really hit a dead end with approach??? Thankyou Edit Eg result 12121212,12121218,12121219,12121211,12121213. the restrictions are that you have to move to your neighbor from any point, you have to start for each position in the matrix i.e each row,col. you can move one step at a time, i.e right, left, up, down and the both diagonal positions. Check the if conditions. i.e if your in (0,0) you can move to either (1,0) or (1,1) or (0,1) i.e three neighbors. if your in (2,2) you can move to eight neighbors. so on...

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  • jQuery action being called when selector isn't met?

    - by dougoftheabaci
    I've been working on a prototype for a client's web site and I've run into a rather significant snag. You can view the prototype here. As you can see, the way it works is you can scroll a set of slides horizontally and, by clicking one, open a stack containing yet more slides. If you then click again on an image in that stack it opens up a lightbox. Clicking on another stack or the close button will close that stack (and open another, as case may be). That all works great. However you get some weird behavior if you do the following: Click to open any stack. Click to open an image's light box (this works best if you click on the image that's level with the main list). Close the light box and the stack either by clicking the close button or clicking on another stack. Click back to the first stack. Instead of reopening the stack, you get the lightbox. This confuses me as the light box should only ever be called if there is a class on the containing UL and that class is removed when the lightbox is closed. I've checked and double-checked this, it's definitely missing. Here are the respective functions: $("ul.hide a.lightbox").live("click",function(){ $("ul.show").removeClass("show").addClass("hide"); $(this).parent().parent().removeClass("hide").addClass("show"); $("ul.hide").animate({opacity: 0.2}); $("ul.show").animate({opacity: 1}); $("#next").animate({opacity: 0.2}); $("#prev").animate({opacity: 0.2}); return false; }); $("ul.show a.lightbox").live("click",function(){ $(this).fancybox().trigger("click"); return false; }); As you can see, in order for the lightbox to be called the containing UL has to have the class of show. However, if you check it with Firebug it won't. For those who are curious, the added .trigger("click"); is because the lightbox will require a double-click to launch otherwise. Any idea how I can fix this?

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  • Nested WHILE loops not acting as expected - Javascript / Google Apps Script

    - by dthor
    I've got a function that isn't acting as intended. Before I continue, I'd like preface this with the fact that I normally program in Mathematica and have been tasked with porting over a Mathematica function (that I wrote) to JavaScript so that it can be used in a Google Docs spreadsheet. I have about 3 hours of JavaScript experience... The entire (small) project is calculating the Gross Die per Wafer, given a wafer and die size (among other inputs). The part that isn't working is where I check to see if any corner of the die is outside of the effective radius, Reff. The function takes a list of X and Y coordinates which, when combined, create the individual XY coord of the center of the die. That is then put into a separate function "maxDistance" that calculates the distance of each of the 4 corners and returns the max. This max value is checked against Reff. If the max is inside the radius, 1 is added to the die count. // Take a list of X and Y values and calculate the Gross Die per Wafer function CoordsToGDW(Reff,xSize,ySize,xCoords,yCoords) { // Initialize Variables var count = 0; // Nested loops create all the x,y coords of the die centers for (var i = 0; i < xCoords.length; i++) { for (var j = 0; j < yCoords.length, j++) { // Add 1 to the die count if the distance is within the effective radius if (maxDistance(xCoords[i],yCoords[j],xSize,ySize) <= Reff) {count = count + 1} } } return count; } Here are some examples of what I'm getting: xArray={-52.25, -42.75, -33.25, -23.75, -14.25, -4.75, 4.75, 14.25, 23.75, 33.25, 42.75, 52.25, 61.75} yArray={-52.5, -45.5, -38.5, -31.5, -24.5, -17.5, -10.5, -3.5, 3.5, 10.5, 17.5, 24.5, 31.5, 38.5, 45.5, 52.5, 59.5} CoordsToGDW(45,9.5,7.0,xArray,yArray) returns: 49 (should be 72) xArray={-36, -28, -20, -12, -4, 4, 12, 20, 28, 36, 44} yArray={-39, -33, -27, -21, -15, -9, -3, 3, 9, 15, 21, 27, 33, 39, 45} CoordsToGDW(32.5,8,6,xArray,yArray) returns: 39 (should be 48) I know that maxDistance() is returning the correct values. So, where's my simple mistake? Also, please forgive me writing some things in Mathematica notation... Edit #1: A little bit of formatting. Edit #2: Per showi, I've changed WHILE loops to FOR loops and replaced <= with <. Still not the right answer. It did clean things up a bit though... Edit #3: What I'm essentially trying to do is take [a,b] and [a,b,c] and return [[a,a],[a,b],[a,c],[b,a],[b,b],[b,c]]

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  • Java java.util.ConcurrentModificationException error

    - by vijay
    Hi all, please can anybody help me solve this problem last so many days I could not able to solve this error. I tried using synchronized method and other ways but did not work so please help me Error java.util.ConcurrentModificationException at java.util.AbstractList$Itr.checkForComodification(Unknown Source) at java.util.AbstractList$Itr.remove(Unknown Source) at JCA.startAnalysis(JCA.java:103) at PrgMain2.doPost(PrgMain2.java:235) Code public synchronized void startAnalysis() { //set Starting centroid positions - Start of Step 1 setInitialCentroids(); Iterator<DataPoint> n = mDataPoints.iterator(); //assign DataPoint to clusters loop1: while (true) { for (Cluster c : clusters) { c.addDataPoint(n.next()); if (!n.hasNext()) break loop1; } } //calculate E for all the clusters calcSWCSS(); //recalculate Cluster centroids - Start of Step 2 for (Cluster c : clusters) { c.getCentroid().calcCentroid(); } //recalculate E for all the clusters calcSWCSS(); // List copy = new ArrayList(originalList); //synchronized (c) { for (int i = 0; i < miter; i++) { //enter the loop for cluster 1 for (Cluster c : clusters) { for (Iterator<DataPoint> k = c.getDataPoints().iterator(); k.hasNext(); ) { // synchronized (k) { DataPoint dp = k.next(); System.out.println("Value of DP" +dp); //pick the first element of the first cluster //get the current Euclidean distance double tempEuDt = dp.getCurrentEuDt(); Cluster tempCluster = null; boolean matchFoundFlag = false; //call testEuclidean distance for all clusters for (Cluster d : clusters) { //if testEuclidean < currentEuclidean then if (tempEuDt > dp.testEuclideanDistance(d.getCentroid())) { tempEuDt = dp.testEuclideanDistance(d.getCentroid()); tempCluster = d; matchFoundFlag = true; } //if statement - Check whether the Last EuDt is > Present EuDt } //for variable 'd' - Looping between different Clusters for matching a Data Point. //add DataPoint to the cluster and calcSWCSS if (matchFoundFlag) { tempCluster.addDataPoint(dp); //k.notify(); // if(k.hasNext()) k.remove(); for (Cluster d : clusters) { d.getCentroid().calcCentroid(); } //for variable 'd' - Recalculating centroids for all Clusters calcSWCSS(); } //if statement - A Data Point is eligible for transfer between Clusters. // }// syn } //for variable 'k' - Looping through all Data Points of the current Cluster. }//for variable 'c' - Looping through all the Clusters. }//for variable 'i' - Number of iterations. // syn }

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  • Applying styles to a GridView matching certain criteria

    - by NickK
    Hi everyone. I'm fairly new to ASP.Net so it's probably just me being a bit stupid, but I just can't figure out why this isn't working. Basically, I have a GridView control (GridView1) on a page which is reading from a database. I already have a CSS style applied to the GridView and all I want to do is change the background image applied in the style depending on if a certain cell has data in it or not. The way I'm trying to handle this change is updating the CSS class applied to each row through C#. I have the code below doing this: protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e) { GridViewRow row = e.Row; string s = row.Cells[7].Text; if (s.Length > 0) { row.CssClass = "newRowBackground"; } else { row.CssClass = "oldRowBackground"; } } In theory, the data from Cell[7] will either be null or be a string (in this case, likely a person's name). The problem is that when the page loads, every row in the GridView has the new style applied to it, whether it's empty or not. However, when I change it to use hard coded examples, it works fine. So for example, the below would work exactly how I want it to: protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e) { GridViewRow row = e.Row; string s = row.Cells[7].Text; if (s == "Smith") //Matching a name in one of the rows { row.CssClass = "newRowBackground"; } else { row.CssClass = "oldRowBackground"; } } It seems as if the top piece of code is always returning the string with a value greater than 0, but when I check the database the fields are all null (except for my test record of "Smith"). I'm probably doing something very simple that's wrong here, but I can't see what. Like I said, I'm still very new to this. One thing I have tried is changing the argument in the if statement to things like: if (s != null), if (s != "") and if (s == string.empty) all with no luck. Any help is greatly appreciated and don't hesitate to tell me if I'm just being stupid here. :)

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  • Thread sleep and thread join.

    - by Dhruv Gairola
    hi guys, if i put a thread to sleep in a loop, netbeans gives me a caution saying Invoking Thread.sleep in loop can cause performance problems. However, if i were to replace the sleep with join, no such caution is given. Both versions compile and work fine tho. My code is below (check the last few lines for "Thread.sleep() vs t.join()"). public class Test{ //Display a message, preceded by the name of the current thread static void threadMessage(String message) { String threadName = Thread.currentThread().getName(); System.out.format("%s: %s%n", threadName, message); } private static class MessageLoop implements Runnable { public void run() { String importantInfo[] = { "Mares eat oats", "Does eat oats", "Little lambs eat ivy", "A kid will eat ivy too" }; try { for (int i = 0; i < importantInfo.length; i++) { //Pause for 4 seconds Thread.sleep(4000); //Print a message threadMessage(importantInfo[i]); } } catch (InterruptedException e) { threadMessage("I wasn't done!"); } } } public static void main(String args[]) throws InterruptedException { //Delay, in milliseconds before we interrupt MessageLoop //thread (default one hour). long patience = 1000 * 60 * 60; //If command line argument present, gives patience in seconds. if (args.length > 0) { try { patience = Long.parseLong(args[0]) * 1000; } catch (NumberFormatException e) { System.err.println("Argument must be an integer."); System.exit(1); } } threadMessage("Starting MessageLoop thread"); long startTime = System.currentTimeMillis(); Thread t = new Thread(new MessageLoop()); t.start(); threadMessage("Waiting for MessageLoop thread to finish"); //loop until MessageLoop thread exits while (t.isAlive()) { threadMessage("Still waiting..."); //Wait maximum of 1 second for MessageLoop thread to //finish. /*******LOOK HERE**********************/ Thread.sleep(1000);//issues caution unlike t.join(1000) /**************************************/ if (((System.currentTimeMillis() - startTime) > patience) && t.isAlive()) { threadMessage("Tired of waiting!"); t.interrupt(); //Shouldn't be long now -- wait indefinitely t.join(); } } threadMessage("Finally!"); } } As i understand it, join waits for the other thread to complete, but in this case, arent both sleep and join doing the same thing? Then why does netbeans throw the caution?

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  • Casting to derived type problem in C++

    - by GONeale
    Hey there everyone, I am quite new to C++, but have worked with C# for years, however it is not helping me here! :) My problem: I have an Actor class which Ball and Peg both derive from on an objective-c iphone game I am working on. As I am testing for collision, I wish to set an instance of Ball and Peg appropriately depending on the actual runtime type of actorA or actorB. My code that tests this as follows: // Actors that collided Actor *actorA = (Actor*) bodyA->GetUserData(); Actor *actorB = (Actor*) bodyB->GetUserData(); Ball* ball; Peg* peg; if (static_cast<Ball*> (actorA)) { // true ball = static_cast<Ball*> (actorA); } else if (static_cast<Ball*> (actorB)) { ball = static_cast<Ball*> (actorB); } if (static_cast<Peg*> (actorA)) { // also true?! peg = static_cast<Peg*> (actorA); } else if (static_cast<Peg*> (actorB)) { peg = static_cast<Peg*> (actorB); } if (peg != NULL) { [peg hitByBall]; } Once ball and peg are set, I then proceed to run the hitByBall method (objective c). Where my problem really lies is in the casting procedurel Ball casts fine from actorA; the first if (static_cast<>) statement steps in and sets the ball pointer appropriately. The second step is to assign the appropriate type to peg. I know peg should be a Peg type and I previously know it will be actorB, however at runtime, detecting the types, I was surprised to find actually the third if (static_cast<>) statement stepped in and set this, this if statement was to check if actorA was a Peg, which we already know actorA is a Ball! Why would it have stepped here and not in the fourth if statement? The only thing I can assume is how casting works differently from c# and that is it finds that actorA which is actually of type Ball derives from Actor and then it found when static_cast<Peg*> (actorA) is performed it found Peg derives from Actor too, so this is a valid test? This could all come down to how I have misunderstood the use of static_cast. How can I achieve what I need? :) I'm really uneasy about what feels to me like a long winded brute-casting attempt here with a ton of ridiculous if statements. I'm sure there is a more elegant way to achieve a simple cast to Peg and cast to Ball dependent on actual type held in actorA and actorB. Hope someone out there can help! :) Thanks a lot.

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  • PHP apache_request_headers() diagrees with reality (as confirmed by Firebug): why?

    - by Peter Howe
    I have written a web app in PHP which makes use of Ajax requests (made using YUI.util.Connect.asyncRequest). Most of the time, this works fine. The request is sent with an X-Requested-With value of XMLHttpRequest. My PHP controller code uses apache_request_headers() to check whether an incoming request is Ajax or not and all works well. But not always. Intermittently, I'm getting a situation where the Ajax request is sent (and Firebug confirms for me that the headers on the request include an X-Requested-With of XMLHttpRequest) but apache_request_headers() is not returning that header in its list. The output from when I var_dump the apache_request_headers() is as follows (note the lack of X- 'Host' => string 'peterh.labs.example.com' (length=26) 'User-Agent' => string 'Mozilla/5.0 (X11; U; Linux i686; en-GB; rv:1.9.0.3) Gecko/2008101315 Ubuntu/8.10 (intrepid) Firefox/3.0.3' (length=105) 'Accept' => string 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8' (length=63) 'Accept-Language' => string 'en-gb,en;q=0.5' (length=14) 'Accept-Encoding' => string 'gzip,deflate' (length=12) 'Accept-Charset' => string 'ISO-8859-1,utf-8;q=0.7,*;q=0.7' (length=30) 'Keep-Alive' => string '300' (length=3) 'Connection' => string 'keep-alive' (length=10) 'Referer' => string 'http://peterh.labs.example.com/qmail/' (length=40) 'Cookie' => string 'WORKFLOW_SESSION=55f9aff2051746851de453c1f776ad10745354f6' (length=57) 'Pragma' => string 'no-cache' (length=8) 'Cache-Control' => string 'no-cache' (length=8) But Firebug tells me: Request Headers: Host peterh.labs.example.com User-Agent Mozilla/5.0 (X11; U; Linux i686; en-GB; rv:1.9.0.3) Gecko/2008101315 Ubuntu/8.10 (intrepid) Firefox/3.0.3 Accept text/html,application/xhtml+xml,application/xml;q=0.9,**;q=0.8 Accept-Language en-gb,en;q=0.5 Accept-Encoding gzip,deflate Accept-Charset ISO-8859-1,utf-8;q=0.7,*;q=0.7 Keep-Alive 300 Connection keep-alive X-Requested-With XMLHttpRequest Referer http://peterh.labs.example.com/qmail/ Cookie WORKFLOW_SESSION=55f9aff2051746851de453c1f776ad10745354f6 This mismatch is (apparently) intermittent when executing the same code. But I don't believe in "intermittent" when it comes to software! Help!

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  • Need Help with Page Life Cycle(I think it is screwing me up)

    - by chobo2
    Hi I have dragged a empty asp.net table onto my webform. I generate all the rows in the code behind those. Now my table gets filled up and has dropdown lists. When the user hits save I go through all the rows and update the values from the dropdownlist in the db. This works all great. However if 2 columns have each have "Present" then those 2 columns should be not be shown anymore and 2 new columns get put in its place with other dropdown lists. This all works. However you have to refresh the entire page to for the 2 columns that should go away to go away. So what I tried to do is at the end of the button click event. Clear the whole table and then regenerate it. However when I do this then my values are not saved to the database anymore for whatever reason. if (IsPostBack == false) { // check if dummy variables exist in db- If true just generate tables with values in db. If not generate them. } else { // grab the values from the database // generate tables with the values } btn click event { go through all rows in table(foreach loop) update each column in the database with cells in each row. while in foreach loop. //done } So this is how it goes and it works expect(all correct values are saved) the table is just not updated to the user. Does not work if (IsPostBack == false) { // same code as above } // if postback is true do nothing. By the time it gets to the click event it says there is zero rows in the table so nothing happens. btn click event { // same code } Fails also. if (IsPostBack == false) { // same code as above } else { // same code as above but moved into its own method. gernerateTable(); } btn click event { // update all rows // once done clear the Tables rows // call generateTable() } This last one does nothing as for some reason it does not update anything. I don't understand why. So what am I doing wrong with this life cycle something in my process is wrong. The code works just not when I want the table to be updated right away.

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  • Force close while calling mainactivity from widget (android)

    - by Shaji Thorn Blue
    Iam creating a simple widget, by this widget i want to open my mainactivity. Iam sending a unique key from my widget class to check whether my mainactivity is called via widget or not. But as soon as i clicked on my widget my mainactivity get force close. here is code of my widget class... @Override public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] widgets) { // TODO Auto-generated method stub int numofWidgets = widgets.length; for(int i=0;i<numofWidgets;i++){ int widget = widgets[i]; Intent in = new Intent(context, EmergencyButton.class); in.putExtra("uniquevalue", "widget"); PendingIntent pendingintent = PendingIntent.getActivity(context, 0, in, 0); RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.widgetlayout); views.setOnClickPendingIntent(R.id.button, pendingintent); appWidgetManager.updateAppWidget(widget, views); } } And Here is my code of mainactivity where iam checking whether called came from widget or not @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.mainactivity); Intent intentwidget = this.getIntent(); if(intentwidget !=null) { String widgetdata = "nothing"; widgetdata = intentwidget.getExtras().getString("uniquevalue"); if(widgetdata.equals("widget")) { et1.setText(widgetdata); } } } And here is my logcat 11-04 14:57:14.361: E/AndroidRuntime(1701): FATAL EXCEPTION: main 11-04 14:57:14.361: E/AndroidRuntime(1701): java.lang.RuntimeException: Unable to start activityComponentInfo{com.appsionlabs.googlemapv2/com.appsionlabs.googlemapv2.EmergencyButton}: java.lang.NullPointerException 11-04 14:57:14.361: E/AndroidRuntime(1701): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647) 11-04 14:57:14.361: E/AndroidRuntime(1701): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663) 11-04 14:57:14.361: E/AndroidRuntime(1701): at android.app.ActivityThread.access$1500(ActivityThread.java:117) 11-04 14:57:14.361: E/AndroidRuntime(1701): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931) 11-04 14:57:14.361: E/AndroidRuntime(1701): at android.os.Handler.dispatchMessage(Handler.java:99) 11-04 14:57:14.361: E/AndroidRuntime(1701): at android.os.Looper.loop(Looper.java:123) 11-04 14:57:14.361: E/AndroidRuntime(1701): at android.app.ActivityThread.main(ActivityThread.java:3683) 11-04 14:57:14.361: E/AndroidRuntime(1701): at java.lang.reflect.Method.invokeNative(Native Method) 11-04 14:57:14.361: E/AndroidRuntime(1701): at java.lang.reflect.Method.invoke(Method.java:507) 11-04 14:57:14.361: E/AndroidRuntime(1701): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 11-04 14:57:14.361: E/AndroidRuntime(1701): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 11-04 14:57:14.361: E/AndroidRuntime(1701): at dalvik.system.NativeStart.main(Native Method) 11-04 14:57:14.361: E/AndroidRuntime(1701): Caused by: java.lang.NullPointerException 11-04 14:57:14.361: E/AndroidRuntime(1701): at com.appsionlabs.googlemapv2.EmergencyButton.onCreate(EmergencyButton.java:29) 11-04 14:57:14.361: E/AndroidRuntime(1701): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 11-04 14:57:14.361: E/AndroidRuntime(1701): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)

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  • Code Golf: Countdown Number Game

    - by Noldorin
    Challenge Here is the task, inspired by the well-known British TV game show Countdown. The challenge should be pretty clear even without any knowledge of the game, but feel free to ask for clarifications. And if you fancy seeing a clip of this game in action, check out this YouTube clip. It features the wonderful late Richard Whitely in 1997. You are given 6 numbers, chosen at random from the set {1, 2, 3, 4, 5, 6, 8, 9, 10, 25, 50, 75, 100}, and a random target number between 100 and 999. The aim is to make use the six given numbers and the four common arithmetic operations (addition, subtraction, multiplication, division; all over the rational numbers) to generate the target - or as close as possible either side. Each number may only be used once at most, while each arithmetic operator may be used any number of times (including zero.) Note that it does not matter how many numbers are used. Write a function that takes the target number and set of 6 numbers (can be represented as list/collection/array/sequence) and returns the solution in any standard numerical notation (e.g. infix, prefix, postfix). The function must always return the closest-possible result to the target, and must run in at most 1 minute on a standard PC. Note that in the case where more than one solution exists, any single solution is sufficient. Examples: {50, 100, 4, 2, 2, 4}, target 203 e.g. 100 * 2 + 2 + (4 / 4) e.g. (100 + 50) * 4 * 2 / (4 + 2) {25, 4, 9, 2, 3, 10}, target 465 e.g. (25 + 10 - 4) * (9 * 2 - 3) {9, 8, 10, 5, 9, 7), target 241 e.g. ((10 + 9) * 9 * 7) + 8) / 5 Rules Other than mentioned in the problem statement, there are no further restrictions. You may write the function in any standard language (standard I/O is not necessary). The aim as always is to solve the task with the smallest number of characters of code. Saying that, I may not simply accept the answer with the shortest code. I'll also be looking at elegance of the code and time complexity of the algorithm! My Solution I'm attempting an F# solution when I find the free time - will post it here when I have something! Format Please post all answers in the following format for the purpose of easy comparison: Language Number of characters: ??? Fully obfuscated function: (code here) Clear (ideally commented) function: (code here) Any notes on the algorithm/clever shortcuts it takes.

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  • What block is not being tested in my test method? (VS08 Test Framework)

    - by daft
    I have the following code: private void SetControlNumbers() { string controlString = ""; int numberLength = PersonNummer.Length; switch (numberLength) { case (10) : controlString = PersonNummer.Substring(6, 4); break; case (11) : controlString = PersonNummer.Substring(7, 4); break; case (12) : controlString = PersonNummer.Substring(8, 4); break; case (13) : controlString = PersonNummer.Substring(9, 4); break; } ControlNumbers = Convert.ToInt32(controlString); } Which is tested using the following test methods: [TestMethod()] public void SetControlNumbers_Length10() { string pNummer = "9999999999"; Personnummer target = new Personnummer(pNummer); Assert.AreEqual(9999, target.ControlNumbers); } [TestMethod()] public void SetControlNumbers_Length11() { string pNummer = "999999-9999"; Personnummer target = new Personnummer(pNummer); Assert.AreEqual(9999, target.ControlNumbers); } [TestMethod()] public void SetControlNumbers_Length12() { string pNummer = "199999999999"; Personnummer target = new Personnummer(pNummer); Assert.AreEqual(9999, target.ControlNumbers); } [TestMethod()] public void SetControlNumbers_Length13() { string pNummer = "1999999-9999"; Personnummer target = new Personnummer(pNummer); Assert.AreEqual(9999, target.ControlNumbers); } For some reason Visual Studio says that I have 1 block that is not tested despite showing all code in the method under test in blue (ie. the code is covered in my unit tests). Is this because of the fact that I don't have a default value defined in the switch? When the SetControlNumbers() method is called, the string on which it operates have already been validated and checked to see that it conforms to the specification and that the various Substring calls in the switch will generate a string containing 4 chars. I'm just curious as to why it says there is 1 untested block. I'm no unit test guru at all, so I'd love some feedback on this. Also, how can I improve on the conversion after the switch to make it safer other than adding a try-catch block and check for FormatExceptions and OverflowExceptions?

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  • Comet with multiple channels

    - by mark_dj
    Hello, I am writing an web app which needs to subscribe to multiple channels via javascript. I am using Atmosphere and Jersey as backend. However the jQuery plugin they work with only supports 1 channel. I've start buidling my own implementation. Now it works oke, but when i try to subscribe to 2 channels only 1 channel gets notified. Is the XMLHttpRequest blocking the rest of the XMLHttpRequests? Here's my code: function AtmosphereComet(url) { this.Connected = new signals.Signal(); this.Disconnected = new signals.Signal(); this.NewMessage = new signals.Signal(); var xhr = null; var self = this; var gotWelcomeMessage = false; var readPosition; var url = url; var onIncomingXhr = function() { if (xhr.readyState == 3) { if (xhr.status==200) // Received a message { var message = xhr.responseText; console.log(message); if(!gotWelcomeMessage && message.indexOf("") -1) { gotWelcomeMessage = true; self.Connected.dispatch(sprintf("Connected to %s", url)); } else { self.NewMessage.dispatch(message.substr(readPosition)); } readPosition = this.responseText.length; } } else if (this.readyState == 4) { self.disconnect(); } } var getXhr = function() { if ( window.location.protocol !== "file:" ) { try { return new window.XMLHttpRequest(); } catch(xhrError) {} } try { return new window.ActiveXObject("Microsoft.XMLHTTP"); } catch(activeError) {} } this.connect = function() { xhr = getXhr(); xhr.onreadystatechange = onIncomingXhr; xhr.open("GET", url, true); xhr.send(null); } this.disconnect = function() { xhr.onreadystatechange = null; xhr.abort(); } this.send = function(message) { } } And the test code: var connection1 = AtmosphereConnection("http://192.168.1.145:9999/botenveiling/b/product/status/2", AtmosphereComet); var connection2 = AtmosphereConnection("http://192.168.1.145:9999/botenveiling/b/product/status/1", AtmosphereComet); var output = function(msg) { alert(output); }; connection1.NewMessage.add(output); connection2.NewMessage.add(output); connection1.connect(); In AtmosphereConnection I instantiate the given AtmosphereComet with "new". I iterate over the object to check if it has to methods: "send", "connect", "disconnect". The reason for this is that i can switch the implementation later on when i complete the websocket implementation :) However I think the problem rests with the XmlHttpRequest object, or am i mistaken? P.S.: signals.Signal is a js observer/notifier library: http://millermedeiros.github.com/js-signals/ Testing: Firefox 3.6.1.3

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  • How do I determine if a property was overriden?

    - by Benjamin
    Hello I am doing a project that where I need to register all the properties, because of the system being so huge it would require a lot of work to register all the properties that i want to be dependent for the purpose of Xaml. The goal is to find all properties that are on the top of the tree. so basically public class A{ public int Property1 { get; set; } } public class B : A{ public int Property2 { get; set; } public virtual int Property3 { get; set; } } public class C : B{ public override int Property3 { get; set; } public int Property4 { get; set; } public int Property5 { get; set; } } The end result would be something like this A.Prorperty1 B.Property2 B.Property3 C.Property4 C.Property5 If you notice I don't want to accept overridden properties because of the way I search for the properties if I do something like this C.Property3 for example and it cannot find it it will check C's basetype and there it will find it. This is what I have so far. public static void RegisterType( Type type ) { PropertyInfo[] properties = type.GetProperties( BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly | BindingFlags.GetProperty | BindingFlags.SetProperty ); if ( properties != null && properties.Length > 0 ) { foreach ( PropertyInfo property in properties ) { // if the property is an indexers then we ignore them if ( property.Name == "Item" && property.GetIndexParameters().Length > 0 ) continue; // We don't want Arrays or Generic Property Types if ( (property.PropertyType.IsArray || property.PropertyType.IsGenericType) ) continue; // Register Property } } } What I want are the following: Public properties, that are not overridden, not static, not private Either get and set properties are allowed They are not an array or a generic type They are the top of the tree ie C class in the example is the highest (The property list example is exactly what I am looking for) They are not an indexer property ( this[index] ) Any help will be much appreciated =).

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  • Dynamically loaded jQuery with GreaseMonkey inconsistent on pages (refreshing seems to fix it)... do

    - by uprightnetizen
    Hi, I want a custom page analysis footer on every site I visit... so I've used a method to attach JQuery to unsafeWindow. I then create a floating footer on the page. I want to be able to call commands in a menu, do some processing, then put the results in the footer. Unfortunately it sometimes works, sometimes it doesn't. At least two alerts should happen in the printOutput function. Sometimes it only fires one, then it (crashes?) without error? On other pages, both alerts fire and it finds the element, but it doesn't add the extra text. (e.g. www.linode.com) Refreshing the page, then running the printOutput command again seems to always work. Does anyone know what's going on??? The userscript can be installed at: http://www.captionwizard.com/test/page_analysis.user.js // ==UserScript== // @name page_analysis // @namespace markspace // @description Page Analysis // @include http://*/* // ==/UserScript== (function() { // Add jQuery var GM_JQ = document.createElement('script'); GM_JQ.src = 'http://code.jquery.com/jquery-1.4.2.min.js'; GM_JQ.type = 'text/javascript'; document.getElementsByTagName('head')[0].appendChild(GM_JQ); var jqueryActive = false; //Check if jQuery's loaded function GM_wait() { if(typeof unsafeWindow.jQuery == 'undefined') { window.setTimeout(GM_wait,100); } else { $ = unsafeWindow.jQuery; letsJQuery(); } } GM_wait(); function letsJQuery() { jqueryActive = true; setupOutputFooter(); } /******************************* Analysis FOOTER Functions ******************************/ function printOutput(someText) { alert('printing output'); if($('div.analysis_footer').length) { alert('is here - appending'); $('div.analysis_footer').append('<br>' + someText); } else { alert('not here - trying again'); setupOutputFooter(); $('div.analysis_footer').append('<br>' + someText); } } GM_registerMenuCommand("Test Output", testOutput, "k", "control", "k" ); function testOutput() { printOutput('testing this'); } function setupOutputFooter() { $('<div class="analysis_footer">Page Analysis Footer:</div>').appendTo('body'); $('div.analysis_footer').css('position','fixed').css('bottom', '0px').css('background-color','#F8F8F8'); $('div.analysis_footer').css('width','100%').css('color','#3B3B3B').css('font-size', '0.8em'); $('div.analysis_footer').css('font-family', '"Myriad",Verdana,Arial,Helvetica,sans-serif').css('padding', '5px'); $('div.analysis_footer').css('border-top', '1px solid black').css('text-align', 'left'); } }());

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  • How do I create a loop based off this array?

    - by dmanexe
    I'm trying to process this array, first testing for the presence of a check, then extrapolating the data from quantity to return a valid price. Here's the input for fixed amounts of items, with no variable quantity. <input type="checkbox" name="measure[<?=$item->id?>][checked]" value="<?=$item->id?>"> <input type="hidden" name="measure[<?=$item->id?>][quantity]" value="1" /> Here's the inputs for variable amounts of items. <input type="checkbox" name="measure[<?=$item->id?>][checked]" value="<?=$item->id?>"> <input class="item_mult" value="0" type="text" name="measure[<?=$item->id?>][quantity]" /> So, the resulting array is multidimensional. Here's an output: Array ( [1] => Array ( [quantity] => 1 ) [2] => Array ( [quantity] => 1 ) [3] => Array ( [quantity] => 1 ) ... [14] => Array ( [checked] => 14 [quantity] => 999 ) ) Here's the loop I'm using to take this array and process items checked off the form in the first place. I guess the question essentially boils down to how do I structure my conditional statement to incorporate the multi-dimensional array? foreach($field as $value): if ($value['checked'] == TRUE) { $query = $this->db->get_where('items', array('id' => $value['checked']))->row(); #Test to see if quantity input is present if ($value['quantity'] == TRUE) { $newprice = $value['quantity'] * $query->price; $totals[] = $newprice; } #Just return the base value if not else { $newprice = $query->price; $totals[] = $newprice; } } else { } ?> <p><?=$query->name?> - <?=money_format('%(#10n', $newprice)?></p> <? endforeach; ?>

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  • A two player game over the intranet..

    - by Santwana
    Hi everybody.. I am a student of 3rd year engineering and only a novice in my programming skills. I need some help with my project.. I wish to develop a two player game to be played over the network (Intranet). I want to develop a simple website with a few html pages for this.My ideas for the project run as follows: 1.People can log in from different systems and check who ever is online on the network currently. the page also shows who is playing with whom. 2.If a person is interested in playing with a player who is currently online, he sends a request of which the other player is somehow notified( using a message or an alert on his profile page..) 3.If the player accepts the request, a game is started. This is exactly where I am clueless.. How can I make them play the game? I need to develop a turn based game with two players, eg chessboard.. how can I do this? The game has to be played live.. and it is time tracked. i need your help with coding the above.. the other features i wish to include are: 4.The game could not be abruptly terminated by any one if the users.The request to terminate the game should be sent to the other player first and only if he accepts can the game be terminated. Whoever wins the game would get a plus 10 on their credit and if he terminated he gets a minus 10. The credits remains constant even if he loses but the success percentage is reduced. 6.The player with highest winning percentage is projected as the player of the week on the home page and he can post a challenge to all others.. I only have an intermediate knowledge of core java and know the basics of Swing and Awt. I am not at all familiar with networking in java right now. I have 5 to 6 weeks of time for developing the project but I hope to learn the things before I start my project. i would prefer to use a lan to illustrate the project and I know only java,jsp,oracle,html and bit of xml to develop my proj. Also I wish to know if I can code this within 6 weeks, would it be too difficult or complicated? Please spare some time to tell me. Please.. please.. I need your suggestions and help.. thank you so much..

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  • Replace Components.classesByID with document.implementation.createDocument

    - by Earl Smith
    I am not the author of this code, but it is no longer maintained. So I am trying to fix it, but I have very little experience in javascript. Since Firefox 9, Components.classesByID["{3a9cd622-264d-11d4-ba06-0060b0fc76dd}"]. has been obsolete. Instead, it is suggested that document.implementation.createDocument be used. Can someone here show me how to implement these changes? I seem to be, just banging my head with everything I have tried. The example given at Mozilla developer network is: var doc = document.implementation.createDocument ("http://www.w3.org/1999/xhtml", "html", null); var body = document.createElementNS("http://www.w3.org/1999/xhtml", "body"); body.setAttribute("id", "abc"); doc.documentElement.appendChild(body); alert(doc.getElementById("abc")); // [object HTMLBodyElement] and the code in the .jsm I am trying to fix is: this.fgImageData = {}; this.fgImageData["check"] = [ " *", " **", "* ***", "** *** ", "***** ", " *** ", " * "]; this.fgImageData["radio"] = [ " **** ", "******", "******", "******", "******", " **** "]; this.fgImageData["menu-ltr"] = [ "* ", "** ", "*** ", "****", "*** ", "** ", "* "]; this.fgImageData["menu-rtl"] = [ " *", " **", " ***", "****", " ***", " **", " *"]; // I think I'm doing something slightly wrong when creating the document // but I'm not sure. It works though. *FIX* var domi = Components.classesByID["{3a9cd622-264d-11d4-ba06-0060b0fc76dd}"]. createInstance(Components.interfaces.nsIDOMDOMImplementation); this.document = domi.createDocument("http://www.w3.org/1999/xhtml", "html", null); this.canvas = this.document.createElementNS("http://www.w3.org/1999/xhtml", "html:canvas"); for(var name in this.fgImageData) { if (this.fgImageData.hasOwnProperty(name)) { var data = this.fgImageData[name]; var width = data[0].length; var height = data.length; this.canvas.width = width; this.canvas.height = height; var g = this.canvas.getContext("2d"); g.clearRect(0, 0, width, height); var idata = g.getImageData(0, 0, width, height); for(var y=0, oy=0; y<height; y++, oy+=idata.width*4) for(var x=0, ox=oy; x<width; x++, ox+=4) idata.data[ox+3] = data[y][x] == " " ? 0 : 255; this.fgImageData[name] = idata; } } },

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  • HTML5 - Need explanation about outline

    - by RhymeGuy
    So, lets say that I have the following structure: <doctype html> <header> <h1>Header</h1> <article><h2>Article</h2></article> <article><h2>Article</h2></article> </header> <main> <h1>Main content</h1> <article><h2>Article</h2></article> <article><h2>Article</h2></article> <article><h2>Article</h2></article> <article><h2>Article</h2></article> </main> <section> <h1>Sidebar</h1> </section> If i check outline using http://gsnedders.html5.org/outliner/ (or any other), I'll get outline like this: 1. Main content 1. Header 1. Article 2. Article 2. Article 3. Article 4. Article 5. Article 6. Sidebar Which (from my understanding) is not correct. I have thought that it should look like this: 1. Header 1. Article 2. Article 2. Main content 1. Article 2. Article 3. Article 4. Article 3. Sidebar Why this happens? I can get desired outline if I use section element. But id there is main element in HTML structure, then everything breaks (at least for me - it's not how I understood it). Can I achieve desired outline using main element?

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  • Ping remote server and wait to get data

    - by infinity
    Hi I'm building my first application for android and I've reached a point where I can't find a solution even have no idea what to search for in Google. So the problem: I am pinging a remote server with GET request through the application passing some parameters like file_id. Then the server gives back confirmation if the file exists or error otherwise, both in plain text. The error string is $$$ERROR$$$. Actually the confirmation is JSON string that holds the path to the file. If the file doesn't exists on the server it generated the error message and start downloading the file and processing it which normally takes 10-30 seconds. What would be the best way to check if the file is ready for download? I have DownloadFile class that extends AsyncTask but before I reach the point to download the file I need the URL which is dependant on the previous request which is in the main class in the UI thread. Here is some code: public class MainActivity extends Activity { private String getInfo() { // Create a new HttpClient and Post Header HttpClient httpClient = new DefaultHttpClient(); HttpGet httpPost = new HttpGet(infoUrl); StringBuilder sb = null; String data; JSONObject jObject = null; try { HttpResponse response = httpClient.execute(httpPost); // This might be equal "$$$ERROR$$$" if no file exists sb = inputStreamToString(response.getEntity().getContent()); } catch(ClientProtocolException e) { // TODO Auto-generated catch block Log.v("Error: pushItem ClientProtocolException: ", e.toString()); } catch (IOException e) { // TODO Auto-generated catch block Log.v("Error: pushItem IOException: ", e.toString()); } // Clean the data to be complaint JSON format data = sb.toString().replace("info = ", ""); try { jObject = new JSONObject(data); data = jObject.getString("h"); fileTitle = jObject.getString("title"); } catch (JSONException e) { // TODO Auto-generated catch block e.printStackTrace(); } downloadUrl = String.format(downloadUrl, fileId, data); return downloadUrl; } } So my idea was to get the content and if equal to $$$ERROR$$$ go into loop until JSON data is passed but I guess there is better solution. Note: I don't have control over the server output so have to deal with what I have.

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  • SQL Server 2005: Update rows in a specified order (like ORDER BY)?

    - by JMTyler
    I want to update rows of a table in a specific order, like one would expect if including an ORDER BY clause, but SQL Server does not support the ORDER BY clause in UPDATE queries. I have checked out this question which supplied a nice solution, but my query is a bit more complicated than the one specified there. UPDATE TableA AS Parent SET Parent.ColA = Parent.ColA + (SELECT TOP 1 Child.ColA FROM TableA AS Child WHERE Child.ParentColB = Parent.ColB ORDER BY Child.Priority) ORDER BY Parent.Depth DESC; So, what I'm hoping that you'll notice is that a single table (TableA) contains a hierarchy of rows, wherein one row can be the parent or child of any other row. The rows need to be updated in order from the deepest child up to the root parent. This is because TableA.ColA must contain an up-to-date concatenation of its own current value with the values of its children (I realize this query only concats with one child, but that is for the sake of simplicity - the purpose of the example in this question does not necessitate any more verbosity), therefore the query must update from the bottom up. The solution suggested in the question I noted above is as follows: UPDATE messages SET status=10 WHERE ID in (SELECT TOP (10) Id FROM Table WHERE status=0 ORDER BY priority DESC ); The reason that I don't think I can use this solution is because I am referencing column values from the parent table inside my subquery (see WHERE Child.ParentColB = Parent.ColB), and I don't think two sibling subqueries would have access to each others' data. So far I have only determined one way to merge that suggested solution with my current problem, and I don't think it works. UPDATE TableA AS Parent SET Parent.ColA = Parent.ColA + (SELECT TOP 1 Child.ColA FROM TableA AS Child WHERE Child.ParentColB = Parent.ColB ORDER BY Child.Priority) WHERE Parent.Id IN (SELECT Id FROM TableA ORDER BY Parent.Depth DESC); The WHERE..IN subquery will not actually return a subset of the rows, it will just return the full list of IDs in the order that I want. However (I don't know for sure - please tell me if I'm wrong) I think that the WHERE..IN clause will not care about the order of IDs within the parentheses - it will just check the ID of the row it currently wants to update to see if it's in that list (which, they all are) in whatever order it is already trying to update... Which would just be a total waste of cycles, because it wouldn't change anything. So, in conclusion, I have looked around and can't seem to figure out a way to update in a specified order (and included the reason I need to update in that order, because I am sure I would otherwise get the ever-so-useful "why?" answers) and I am now hitting up Stack Overflow to see if any of you gurus out there who know more about SQL than I do (which isn't saying much) know of an efficient way to do this. It's particularly important that I only use a single query to complete this action. A long question, but I wanted to cover my bases and give you guys as much info to feed off of as possible. :) Any thoughts?

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  • Are there any platforms where using structure copy on an fd_set (for select() or pselect()) causes p

    - by Jonathan Leffler
    The select() and pselect() system calls modify their arguments (the 'struct fd_set *' arguments), so the input value tells the system which file descriptors to check and the return values tell the programmer which file descriptors are currently usable. If you are going to call them repeatedly for the same set of file descriptors, you need to ensure that you have a fresh copy of the descriptors for each call. The obvious way to do that is to use a structure copy: struct fd_set ref_set_rd; struct fd_set ref_set_wr; struct fd_set ref_set_er; ... ...code to set the reference fd_set_xx values... ... while (!done) { struct fd_set act_set_rd = ref_set_rd; struct fd_set act_set_wr = ref_set_wr; struct fd_set act_set_er = ref_set_er; int bits_set = select(max_fd, &act_set_rd, &act_set_wr, &act_set_er, &timeout); if (bits_set > 0) { ...process the output values of act_set_xx... } } My question: Are there any platforms where it is not safe to do a structure copy of the struct fd_set values as shown? I'm concerned lest there be hidden memory allocation or anything unexpected like that. (There are macros/functions FD_SET(), FD_CLR(), FD_ZERO() and FD_ISSET() to mask the internals from the application.) I can see that MacOS X (Darwin) is safe; other BSD-based systems are likely to be safe, therefore. You can help by documenting other systems that you know are safe in your answers. (I do have minor concerns about how well the struct fd_set would work with more than 8192 open file descriptors - the default maximum number of open files is only 256, but the maximum number is 'unlimited'. Also, since the structures are 1 KB, the copying code is not dreadfully efficient, but then running through a list of file descriptors to recreate the input mask on each cycle is not necessarily efficient either. Maybe you can't do select() when you have that many file descriptors open, though that is when you are most likely to need the functionality.) There's a related SO question - asking about 'poll() vs select()' which addresses a different set of issues from this question.

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