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  • Is it correct or incorrect for a Java JAR to contain its own dependencies?

    - by 4herpsand7derpsago
    I guess this is a two-part question. I am trying to write my own Ant task (MyFirstTask) that can be used in other project's build.xml buildfiles. To do this, I need to compile and package my Ant task inside its own JAR. Because this Ant task that I have written is fairly complicated, it has about 20 dependencies (other JAR files), such as using XStream for OX-mapping, Guice for DI, etc. I am currently writing the package task in the build.xml file inside the MyFirstTask project (the buildfile that will package myfirsttask.jar, which is the reusable Ant task). I am suddenly realizing that I don't fully understand the intention of a Java JAR. Is it that a JAR should not contain dependencies, and leave it to the runtime configuration (the app container, the runtime environment, etc.) to supply it with the dependencies it needs? I would assume if this is the case, an executable JAR is an exception to the rule, yes? Or, is it the intention for Java JARs to also include their dependencies? Either way, I don't want to be forcing my users to be copying-n-pasting 25+ JARs into their Ant libs; that's just cruel. I like the way WAR files are set up, where the classpath for dependencies is defined under the classes/ directory. I guess, ultimately, I'd like my JAR structure to look like: myfirsttask.jar/ com/ --> the root package of my compiled binaries config/ --> config files, XML, XSD, etc. classes/ --> all dependencies, guice-3.0.jar, xstream-1.4.3.jar, etc. META-INF/ MANIFEST.MF I assume that in order to accomplish this (and get the runtime classpath to also look into the classes/ directory), I'll need to modify the MANIFEST.MF somehow (I know there's a manifest attribute called ClassPath, I believe?). I'm just having a tough time putting everything together, and have a looming/lingering question about the very intent of JARs to begin with. Can someone please confirm whether Oracle intends for JARs to contain their dependencies or not? And, either way, what I would have to do in the manifest (or anywhere else) to make sure that, at runtime, the classpath can find the dependencies stored under the classes/ directory? Thanks in advance!

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  • waiting for 2 different events in a single thread

    - by João Portela
    component A (in C++) - is blocked waiting for alarm signals (not relevant) and IO signals (1 udp socket). has one handler for each of these. component B (java) - has to receive the same information the component A udp socket receives. periodicaly gives instructions that should be sent through component A udp socket. How to join both components? it is strongly desirable that: the changes to attach component B to component A are minimal (its not my code and it is not very pleasent to mess with). the time taken by the new operations (usually communicating with component B) interfere very little with the usual processing time of component A - this means that if the operations are going to take a "some" time I would rather use a thread or something to do them. note: since component A receives udp packets more frequently that it has component B instructions to forward, if necessary, it can only forward the instructions (when available) from the IO handler. my initial ideia was to develop a component C (in C++) that would sit inside the component A code (is this called an adapter?) that when instanciated starts the java process and makes the necessary connections (that not so little overhead in the initialization is not a problem). It would have 2 stacks, one for the data to give component B (lets call it Bstack) and for the data to give component A (lets call it Astack). It would sit on its thread (lets call it new-thread) waiting for data to be available in Bstack to send it over udp, and listen on the udp socket to put data on the Astack. This means that the changes to component A are only: when it receives a new UDP packet put it on the Bstack, and if there is something on the Astack sent it over its UDP socket (I decided for this because this socket would only be used in the main thread). One of the problems is that I don't know how to wait for both of these events at the same time using only one thread. so my questions are: Do I really need to use the main thread to send the data over component A socket or can I do it from the new-thread? (I think the answer is no, but I'm not sure about race conditions on sockets) how to I wait for both events? boost::condition_variable or something similar seems the solution in the case of the stack and boost::asio::io_service io_service.run() seems like the thing to use for the socket. Is there any other alternative solution for this problem that I'm not aware of? Thanks for reading this long text but I really wanted you to understand the problem.

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  • Error:A generic error occurred in GDI+

    - by sanfra1983
    Hi, I created a web project on the server, and when I upload an image shows me the error Error: A generic error occurred in GDI +. I have read many links on the net that talk about this issue, and although I made the changes, nothing went wrong. I was thinking if the case is not an issue of permissions to folders. In fact I have two folders one inside the other. This is the code to resize the image: public Bitmaps ResizeImage (Stream stream, int? width, int? height) ( System.Drawing.Bitmap bmpOut = null; const int defaultWidth = 800; const int defaultHeight = 600; int width = lnWidth == null? defaultWidth: (int) width; int height = lnHeight == null? defaultHeight: (int) height; try ( LoBMP bitmap = new Bitmap (stream); ImageFormat loFormat = loBMP.RawFormat; decimal lnRatio; lnNewWidth int = 0; lnNewHeight int = 0; if (loBMP.Width <& & lnWidth loBMP.Height <lnHeight) ( loBMP return; ) if (loBMP.Width> loBMP.Height) ( lnRatio = (decimal) lnWidth / loBMP.Width; lnNewWidth = lnWidth; decimal = lnTemp loBMP.Height lnRatio *; lnNewHeight = (int) lnTemp; ) else ( lnRatio = (decimal) lnHeight / loBMP.Height; lnNewHeight = lnHeight; decimal = lnTemp loBMP.Width lnRatio *; lnNewWidth = (int) lnTemp; ) bmpOut = new Bitmap (lnNewWidth, lnNewHeight); Graphics g = Graphics.FromImage (bmpOut); g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic; g.FillRectangle (Brushes.White, 0, 0, lnNewWidth, lnNewHeight); g.DrawImage (loBMP, 0, 0, lnNewWidth, lnNewHeight); loBMP.Dispose (); ) catch ( return null; ) bmpOut return; ) and this is the code that I insert in the codebehind: string filepath = AppDomain.CurrentDomain.BaseDirectory + img_veterinario / "; string = filepathM AppDomain.CurrentDomain.BaseDirectory + img_veterinario / img_veterinarioM; Reseize Reseize R = new (); Bitmap = photosFileOriginal r.ResizeImage (fucasiclinici.PostedFile.InputStream, 400, 400); Bitmap = photosFileMiniatura r.ResizeImage (fucasiclinici.PostedFile.InputStream, 72, 72); String filename = Path.GetFileName (fucasiclinici.PostedFile.FileName); photosFileOriginal.Save (Path.Combine (filepath, filename)); photosFileMiniatura.Save (Path.Combine (filepathM, filename)); Can you help me? Thanks

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  • log4bash: Cannot find a way to add MaxBackupIndex to this logger implementation

    - by Syffys
    I have been trying to modify this log4bash implementation but I cannot manage to make it work. Here's a sample: #!/bin/bash TRUE=1 FALSE=0 ############### Added for testing log4bash_LOG_ENABLED=$TRUE log4bash_rootLogger=$TRACE,f,s log4bash_appender_f=file log4bash_appender_f_dir=$(pwd) log4bash_appender_f_file=test.log log4bash_appender_f_roll_format=%Y%m log4bash_appender_f_roll=$TRUE log4bash_appender_f_maxBackupIndex=10 #################################### log4bash_abs(){ if [ "${1:0:1}" == "." ]; then builtin echo ${rootDir}/${1} else builtin echo ${1} fi } log4bash_check_app_dir(){ if [ "$log4bash_LOG_ENABLED" -eq $TRUE ]; then dir=$(log4bash_abs $1) if [ ! -d ${dir} ]; then #log a seperation line mkdir $dir fi fi } # Delete old log files # $1 Log directory # $2 Log filename # $3 Log filename suffix # $4 Max backup index log4bash_delete_old_files(){ ##### Added for testing builtin echo "Running log4bash_delete_old_files $@" &2 ##### if [ "$log4bash_LOG_ENABLED" -eq $TRUE ] && [ -n "$3" ] && [ "$4" -gt 0 ]; then local directory=$(log4bash_abs $1) local filename=$2 local maxBackupIndex=$4 local suffix=$(echo "${3}" | sed -re 's/[^.]/?/g') local logFileList=$(find "${directory}" -mindepth 1 -maxdepth 1 -name "${filename}${suffix}" -type f | xargs ls -1rt) local fileCnt=$(builtin echo -e "${logFileList}" | wc -l) local fileToDeleteCnt=$(($fileCnt-$maxBackupIndex)) local fileToDelete=($(builtin echo -e "${logFileList}" | head -n "${fileToDeleteCnt}" | sed ':a;N;$!ba;s/\n/ /g')) ##### Added for testing builtin echo "log4bash_delete_old_files About to start deletion ${fileToDelete[@]}" &2 ##### if [ ${fileToDeleteCnt} -gt 0 ]; then for f in "${fileToDelete[@]}"; do #### Added for testing builtin echo "Removing file ${f}" &2 #### builtin eval rm -f ${f} done fi fi } #Appender # $1 Log directory # $2 Log file # $3 Log file roll ? # $4 Appender Name log4bash_filename(){ builtin echo "Running log4bash_filename $@" &2 local format local filename log4bash_check_app_dir "${1}" if [ ${3} -eq 1 ];then local formatProp=${4}_roll_format format=${!formatProp} if [ -z ${format} ]; then format=$log4bash_appender_file_format fi local suffix=.`date "+${format}"` filename=${1}/${2}${suffix} # Old log files deletion local previousFilenameVar=int_${4}_file_previous local maxBackupIndexVar=${4}_maxBackupIndex if [ -n "${!maxBackupIndexVar}" ] && [ "${!previousFilenameVar}" != "${filename}" ]; then builtin eval export $previousFilenameVar=$filename log4bash_delete_old_files "${1}" "${2}" "${suffix}" "${!maxBackupIndexVar}" else builtin echo "log4bash_filename $previousFilenameVar = ${!previousFilenameVar}" fi else filename=${1}/${2} fi builtin echo $filename } ######################## Added for testing filename_caller(){ builtin echo "filename_caller Call $1" output=$(log4bash_abs $(log4bash_filename "${log4bash_appender_f_dir}" "${log4bash_appender_f_file}" "1" "log4bash_appender_f" )) builtin echo ${output} } #### Previous logs generation for i in {1101..1120}; do file="${log4bash_appender_f_file}.2012${i:2:3}" builtin echo "${file} $i" touch -m -t "2012${i}0000" ${log4bash_appender_f_dir}/$file done for i in {1..4}; do filename_caller $i done I expect log4bash_filename function to step into the following if only when the calculated log filename is different from the previous one: if [ -n "${!maxBackupIndexVar}" ] && [ "${!previousFilenameVar}" != "${filename}" ]; then For this scenario to apply, I'd need ${!previousFilenameVar} to be correctly set, but it's not the case, so log4bash_filename steps into this if all the time which is really not necessary... It looks like the issue is due to the following line not working properly: builtin eval export $previousFilenameVar=$filename I have a some theories to explain why: in the original code, functions are declared and exported as readonly which makes them unable to modify global variable. I removed readonly declarations in the above sample, but probleme persists. Function calls are performed in $() which should make them run into seperated shell instances so variable modified are not exported to the main shell But I cannot manage to find a workaround to this issue... Any help is appreciated, thanks in advance!

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  • unable to trigger event in IE during clonning

    - by Abhimanyu
    Following is the code which will clone a set of div with their events(onclick) which is working fine for FF but in case of IE it is not firing events associated with each div. <html> <head> <style type='text/css'> .firstdiv{ border:1px solid red; } </style> <script language="JavaScript"> function show_tooltip(idx,condition,ev) { alert(idx +"=="+condition+"=="+ev); } function createCloneNode () { var cloneObj = document.getElementById("firstdiv").cloneNode(true); document.getElementById("maindiv").appendChild(cloneObj); } function init(){ var mainDiv = document.createElement("div"); mainDiv.id = 'maindiv'; var firstDiv = document.createElement("div"); firstDiv.id ='firstdiv'; firstDiv.className ='firstdiv'; for(var j=0;j<4;j++) { var summaryDiv = document.createElement("div"); summaryDiv.id = "sDiv"+j summaryDiv.className ='summaryDiv'; summaryDiv.onmouseover = function() {this.setAttribute("style","text-decoration:underline;cursor:pointer;");} summaryDiv.onmouseout = function() {this.setAttribute("style","text-decoration:none;");} summaryDiv.setAttribute("onclick", "show_tooltip("+j+",'view_month',event)"); summaryDiv.innerHTML = 'Div'+j; firstDiv.appendChild(summaryDiv); } mainDiv.appendChild(firstDiv); var secondDiv = document.createElement("div"); var linkDiv = document.createElement("div"); linkDiv.innerHTML ='create clone of above element'; linkDiv.onclick = function() { createCloneNode(); } secondDiv.appendChild(linkDiv); mainDiv.appendChild(secondDiv); document.body.appendChild(mainDiv); } </script> </head> <body> <script language="JavaScript"> init() </script> </body> </html> can anybody tell me whats the problem in above code please correct me..

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  • How to pass operators as parameters

    - by Rodion Ingles
    I have to load an array of doubles from a file, multiply each element by a value in a table (different values for different elements), do some work on it, invert the multiplication (that is, divide) and then save the data back to file. Currently I implement the multiplication and division process in two separate methods. Now there is some extra work behind the scenes but apart from the specific statements where the multiplication/division occurs, the rest of the code is identical. As you can imagine, with this approach you have to be very careful making any changes. The surrounding code is not trivial, so its either a case of manually editing each method or copying changes from one method to the other and remembering to change the * and / operators. After too many close calls I am fed up of this and would like to make a common function which implements the common logic and two wrapper functions which pass which operator to use as a parameter. My initial approach was to use function pointers: MultiplyData(double data) { TransformData(data, &(operator *)); } DivideData(double data) { TransformData(data, &(operator /)); } TransformData(double data, double (*func)(double op1, double op2)) { /* Do stuff here... */ } However, I can't pass the operators as pointers (is this because it is an operator on a native type?), so I tried to use function objects. Initially I thought that multiplies and divides functors in <functional> would be ideal: MultiplyData(double data) { std::multiplies<double> multFunct; TransformData(data, &multFunct); } DivideData(double data) { std::divides<double> divFunct; TransformData(data, &divFunct); } TransformData(double data, std::binary_function<double, double, double> *funct) { /* Do stuff here... */ } As you can see I was trying to use a base class pointer to pass the functor polymorphically. The problem is that std::binary_function does not declare an operator() member for the child classes to implement. Is there something I am missing, or is the solution to implement my own functor heirarchy (which really seems more trouble than it is worth)?

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  • Memory leaks getting sub-images from video (cvGetSubRect)

    - by dnul
    Hi, i'm trying to do video windowing that is: show all frames from a video and also some sub-image from each frame. This sub-image can change size and be taken from a different position of the original frame. So , the code i've written does basically this: cvQueryFrame to get a new image from the video Create a new IplImage (img) with sub-image dimensions ( window.height,window.width) Create a new Cvmat (mat) with sub-image dimensions ( window.height,window.width) CvGetSubRect(originalImage,mat,window) seizes the sub-image transform Mat (cvMat) to img (IplImage) using cvGetImage my problem is that for each frame i create new IplImage and cvMat which take a lot of memory and when i try to free the allocated memory I get a segmentation fault or in the case of the CvMat the allocated space does not get free (valgrind keeps telling me its definetly lost space). the following code does it: int main(void){ CvCapture* capture; CvRect window; CvMat * tmp; //window size window.x=0;window.y=0;window.height=100;window.width=100; IplImage * src=NULL,*bk=NULL,* sub=NULL; capture=cvCreateFileCapture( "somevideo.wmv"); while((src=cvQueryFrame(capture))!=NULL){ cvShowImage("common",src); //get sub-image sub=cvCreateImage(cvSize(window.height,window.width),8,3); tmp =cvCreateMat(window.height, window.width,CV_8UC1); cvGetSubRect(src, tmp , window); sub=cvGetImage(tmp, sub); cvShowImage("Window",sub); //free space if(bk!=NULL) cvReleaseImage(&bk); bk=sub; cvReleaseMat(&tmp); cvWaitKey(20); //window dimensions changes window.width++; window.height++; } } cvReleaseMat(&tmp); does not seem to have any effect on the total amount of lost memory, valgrind reports the same amount of "definetly lost" memory if i comment or uncomment this line. cvReleaseImage(&bk); produces a segmentation fault. notice i'm trying to free the previous sub-frame which i'm backing up in the bk variable. If i comment this line the program runs smoothly but with lots of memory leaks I really need to get rid of memory leaks, can anyone explain me how to correct this or even better how to correctly perform image windowing? Thank you

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  • OpenGL Coordinate system confusion

    - by user146780
    Maybe I set up GLUT wrong. Basically I want verticies to be reletive to their size in pixels. Ex:right now if I create a hexagon, it hakes up the whole screen even though the units are 6. #include <iostream> #include <stdlib.h> //Needed for "exit" function #include <cmath> //Include OpenGL header files, so that we can use OpenGL #ifdef __APPLE__ #include <OpenGL/OpenGL.h> #include <GLUT/glut.h> #else #include <GL/glut.h> #endif using namespace std; //Called when a key is pressed void handleKeypress(unsigned char key, //The key that was pressed int x, int y) { //The current mouse coordinates switch (key) { case 27: //Escape key exit(0); //Exit the program } } //Initializes 3D rendering void initRendering() { //Makes 3D drawing work when something is in front of something else glEnable(GL_DEPTH_TEST); } //Called when the window is resized void handleResize(int w, int h) { //Tell OpenGL how to convert from coordinates to pixel values glViewport(0, 0, w, h); glMatrixMode(GL_PROJECTION); //Switch to setting the camera perspective //Set the camera perspective glLoadIdentity(); //Reset the camera gluPerspective(45.0, //The camera angle (double)w / (double)h, //The width-to-height ratio 1.0, //The near z clipping coordinate 200.0); //The far z clipping coordinate } //Draws the 3D scene void drawScene() { //Clear information from last draw glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity(); //Reset the drawing perspective glPolygonMode(GL_FRONT_AND_BACK, GL_FILL); glBegin(GL_POLYGON); //Begin quadrilateral coordinates //Trapezoid glColor3f(255,0,0); for(int i = 0; i < 6; ++i) { glVertex2d(sin(i/6.0*2* 3.1415), cos(i/6.0*2* 3.1415)); } glEnd(); //End quadrilateral coordinates glutSwapBuffers(); //Send the 3D scene to the screen } int main(int argc, char** argv) { //Initialize GLUT glutInit(&argc, argv); glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH); glutInitWindowSize(400, 400); //Set the window size //Create the window glutCreateWindow("Basic Shapes - videotutorialsrock.com"); initRendering(); //Initialize rendering //Set handler functions for drawing, keypresses, and window resizes glutDisplayFunc(drawScene); glutKeyboardFunc(handleKeypress); glutReshapeFunc(handleResize); glutMainLoop(); //Start the main loop. glutMainLoop doesn't return. return 0; //This line is never reached } How can I make it so that a polygon of 0,0 10,0 10,10 0,10 defines a polygon starting at the top left of the screen and is a width and height of 10 pixels? Thanks

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  • Calculate minimum moves to solve a puzzle

    - by Luke
    I'm in the process of creating a game where the user will be presented with 2 sets of colored tiles. In order to ensure that the puzzle is solvable, I start with one set, copy it to a second set, then swap tiles from one set to another. Currently, (and this is where my issue lies) the number of swaps is determined by the level the user is playing - 1 swap for level 1, 2 swaps for level 2, etc. This same number of swaps is used as a goal in the game. The user must complete the puzzle by swapping a tile from one set to the other to make the 2 sets match (by color). The order of the tiles in the (user) solved puzzle doesn't matter as long as the 2 sets match. The problem I have is that as the number of swaps I used to generate the puzzle approaches the number of tiles in each set, the puzzle becomes easier to solve. Basically, you can just drag from one set in whatever order you need for the second set and solve the puzzle with plenty of moves left. What I am looking to do is after I finish building the puzzle, calculate the minimum number of moves required to solve the puzzle. Again, this is almost always less than the number of swaps used to create the puzzle, especially as the number of swaps approaches the number of tiles in each set. My goal is to calculate the best case scenario and then give the user a "fudge factor" (i.e. 1.2 times the minimum number of moves). Solving the puzzle in under this number of moves will result in passing the level. A little background as to how I currently have the game configured: Levels 1 to 10: 9 tiles in each set. 5 different color tiles. Levels 11 to 20: 12 tiles in each set. 7 different color tiles. Levels 21 to 25: 15 tiles in each set. 10 different color tiles. Swapping within a set is not allowed. For each level, there will be at least 2 tiles of a given color (one for each set in the solved puzzle). Is there any type of algorithm anyone could recommend to calculate the minimum number of moves to solve a given puzzle?

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  • small scale web site - global javascript file style/format/pattern - improving maintainability

    - by yaya3
    I frequently create (and inherit) small to medium websites where I have the following sort of code in a single file (normally named global.js or application.js or projectname.js). If functions get big, I normally put them in a seperate file, and call them at the bottom of the file below in the $(document).ready() section. If I have a few functions that are unique to certain pages, I normally have another switch statement for the body class inside the $(document).ready() section. How could I restructure this code to make it more maintainable? Note: I am less interested in the functions innards, more so the structure, and how different types of functions should be dealt with. I've also posted the code here - http://pastie.org/999932 in case it makes it any easier var ProjectNameEnvironment = {}; function someFunctionUniqueToTheHomepageNotWorthMakingConfigurable () { $('.foo').hide(); $('.bar').click(function(){ $('.foo').show(); }); } function functionThatIsWorthMakingConfigurable(config) { var foo = config.foo || 700; var bar = 200; return foo * bar; } function globallyRequiredJqueryPluginTrigger (tooltip_string) { var tooltipTrigger = $(tooltip_string); tooltipTrigger.tooltip({ showURL: false ... }); } function minorUtilityOneLiner (selector) { $(selector).find('li:even').not('li ul li').addClass('even'); } var Lightbox = {}; Lightbox.setup = function(){ $('li#foo a').attr('href','#alpha'); $('li#bar a').attr('href','#beta'); } Lightbox.init = function (config){ if (typeof $.fn.fancybox =='function') { Lightbox.setup(); var fade_in_speed = config.fade_in_speed || 1000; var frame_height = config.frame_height || 1700; $(config.selector).fancybox({ frameHeight : frame_height, callbackOnShow: function() { var content_to_load = config.content_to_load; ... }, callbackOnClose : function(){ $('body').height($('body').height()); } }); } else { if (ProjectNameEnvironment.debug) { alert('the fancybox plugin has not been loaded'); } } } // ---------- order of execution ----------- $(document).ready(function () { urls = urlConfig(); (function globalFunctions() { $('.tooltip-trigger').each(function(){ globallyRequiredJqueryPluginTrigger(this); }); minorUtilityOneLiner('ul.foo') Lightbox.init({ selector : 'a#a-lightbox-trigger-js', ... }); Lightbox.init({ selector : 'a#another-lightbox-trigger-js', ... }); })(); if ( $('body').attr('id') == 'home-page' ) { (function homeFunctions() { someFunctionUniqueToTheHomepageNotWorthMakingConfigurable (); })(); } });

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  • How do we simplify this kind of code in Java? Something like macros in C?

    - by Terry Li
    public static boolean diagonals(char[][] b, int row, int col, int l) { int counter = 1; // because we start from the current position char charAtPosition = b[row][col]; int numRows = b.length; int numCols = b[0].length; int topleft = 0; int topright = 0; int bottomleft = 0; int bottomright = 0; for (int i=row-1,j=col-1;i>=0 && j>=0;i--,j--) { if (b[i][j]==charAtPosition) { topleft++; } else { break; } } for (int i=row-1,j=col+1;i>=0 && j<=numCols;i--,j++) { if (b[i][j]==charAtPosition) { topright++; } else { break; } } for (int i=row+1,j=col-1;i<=numRows && j>=0;i++,j--) { if (b[i][j]==charAtPosition) { bottomleft++; } else { break; } } for (int i=row+1,j=col+1;i<=numRows && j<=numCols;i++,j++) { if (b[i][j]==charAtPosition) { bottomright++; } else { break; } } return topleft + bottomright + 1 >= l || topright + bottomleft + 1 >= l; //in this case l is 5 } After I was done posting the code above here, I couldn't help but wanted to simplify the code by merging the four pretty much the same loops into one method. Here's the kind of method I want to have: public int countSteps(char horizontal, char vertical) { } Two parameters horizontal and vertical can be either + or - to indicate the four directions to walk in. What I want to see if possible at all is i++; is generalized to i horizontal horizontal; when horizontal taking the value of +. What I don't want to see is if or switch statements, for example: public int countSteps(char horizontal, char vertical) { if (horizontal == '+' && vertical == '-') { for (int i=row-1,j=col+1;i>=0 && j<=numCols;i--,j++) { if (b[i][j]==charAtPosition) { topright++; } else { break; } } } else if (horizontal == '+' && vertical == '+') { for (int i=row+1,j=col+1;i>=0 && j<=numCols;i++,j++) { if (b[i][j]==charAtPosition) { topright++; } else { break; } } } else if () { } else { } } Since it is as tedious as the original one. Note also that the comparing signs for the loop condition i>=0 && j<=numCols; for example, >= && <= have correspondence with the value combination of horizontal and vertical. Sorry for my bad wording, please let me know if anything is not clear.

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  • Are Objective-C initializers allowed to share the same name?

    - by NattKatt
    I'm running into an odd issue in Objective-C when I have two classes using initializers of the same name, but differently-typed arguments. For example, let's say I create classes A and B: A.h: #import <Cocoa/Cocoa.h> @interface A : NSObject { } - (id)initWithNum:(float)theNum; @end A.m: #import "A.h" @implementation A - (id)initWithNum:(float)theNum { self = [super init]; if (self != nil) { NSLog(@"A: %f", theNum); } return self; } @end B.h: #import <Cocoa/Cocoa.h> @interface B : NSObject { } - (id)initWithNum:(int)theNum; @end B.m: #import "B.h" @implementation B - (id)initWithNum:(int)theNum { self = [super init]; if (self != nil) { NSLog(@"B: %d", theNum); } return self; } @end main.m: #import <Foundation/Foundation.h> #import "A.h" #import "B.h" int main (int argc, const char * argv[]) { NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; A *a = [[A alloc] initWithNum:20.0f]; B *b = [[B alloc] initWithNum:10]; [a release]; [b release]; [pool drain]; return 0; } When I run this, I get the following output: 2010-04-26 20:44:06.820 FnTest[14617:a0f] A: 20.000000 2010-04-26 20:44:06.823 FnTest[14617:a0f] B: 1 If I reverse the order of the imports so it imports B.h first, I get: 2010-04-26 20:45:03.034 FnTest[14635:a0f] A: 0.000000 2010-04-26 20:45:03.038 FnTest[14635:a0f] B: 10 For some reason, it seems like it's using the data type defined in whichever @interface gets included first for both classes. I did some stepping through the debugger and found that the isa pointer for both a and b objects ends up the same. I also found out that if I no longer make the alloc and init calls inline, both initializations seem to work properly, e.g.: A *a = [A alloc]; [a initWithNum:20.0f]; If I use this convention when I create both a and b, I get the right output and the isa pointers seem to be different for each object. Am I doing something wrong? I would have thought multiple classes could have the same initializer names, but perhaps that is not the case.

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  • Urgent help needed on How to update NSMutableDictionary. My code doesn't work.

    - by dawatson833
    I've populated an array using. arrSettings = [[NSMutableArray alloc] initWithContentsOfFile:[self settingsPath]]; The file is a plist with the root as an array and then a dictionary with three three keys defined as number. I've also tried setting the keys to string. I display the values in the plist file on a view using. diaper = [[arrSettings objectAtIndex:0] objectForKey:@"Diaper Expenses"]; oil = [[arrSettings objectAtIndex:0] objectForKey:@"Oil Used"]; tree = [[arrSettings objectAtIndex:0] objectForKey:@"Wood Used"]; This code works fine, the values in the dictionary are assigned to the variables and they are displayed. The user can make changes and then press a save button. I use this code to extract the dictionary part of the array so I can update it. The assignment to editDictionary works. I've double checked the key names including case and that is correct. editDictionary = [[NSMutableDictionary alloc] init]; editDictionary = [arrSettings objectAtIndex:0]; NSNumber *myNumber = [NSNumber numberWithFloat:diaperAmount]; [editDictionary setValue:myNumber forKey:@"Diaper Expenses"]; myNumber = [NSNumber numberWithFloat:oilAmount]; [editDictionary setValue:myNumber forKey:@"Oil Used"]; myNumber = [NSNumber numberWithFloat:treeAmount]; [editDictionary setValue:myNumber forKey:@"Wood Used"]; In this example I've used a nsnumber. But I've also tried the xxxAmount field as part of SetValue instead of creating a NSNumber. Neither implementation works. Several strange things happen. Sometimes the first two setvalue statements work, but the last setvalue fails with a EXC_BAD_ACCESS failure. Other times the first setValue fails with the same error. I have no idea why the first two sometimes work. I'm at a loss of what to do next. I've tried several implentations and none of them work. Also, in the debugger how can I display the editDictionary elements. I can see editDictionary, but I don't know how to display the individual elements.

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  • Improving Javascript Load Times - Concatenation vs Many + Cache

    - by El Yobo
    I'm wondering which of the following is going to result in better performance for a page which loads a large amount of javascript (jQuery + jQuery UI + various other javascript files). I have gone through most of the YSlow and Google Page Speed stuff, but am left wondering about a particular detail. A key thing for me here is that the site I'm working on is not on the public net; it's a business to business platform where almost all users are repeat visitors (and therefore with caches of the data, which is something that YSlow assumes will not be the case for a large number of visitors). First up, the standard approach recommended by tools such as YSlow is to concatenate it, compress it, and serve it up in a single file loaded at the end of your page. This approach sounds reasonably effective, but I think that a key part of the reasoning here is to improve performance for users without cached data. The system I currently have is something like this * All javascript files are compressed and loaded at the bottom of the page * All javascript files have far future cache expiration dates, so will remain (for most users) in the cache for a long time * Pages only load the javascript files that they require, rather than loading one monolithic file, most of which will not be required Now, my understanding is that, if the cache expiration date for a javascript file has not been reached, then the cached version is used immediately; there is no HTTP request sent at to the server at all. If this is correct, I would assume that having multiple tags is not causing any performance penalty, as I'm still not having any additional requests on most pages (recalling from above that almost all users have populated caches). In addition to this, not loading the JS means that the browser doesn't have to interpret or execute all this additional code which it isn't going to need; as a B2B application, most of our users are unfortunately stuck with IE6 and its painfully slow JS engine. Another benefit is that, when code changes, only the affected files need to be fetched again, rather than the whole set (granted, it would only need to be fetched once, so this is not so much of a benefit). I'm also looking at using LabJS to allow for parallel loading of the JS when it's not cached. So, what do people think is a better approach? In a similar vein, what do you think about a similar approach to CSS - is monolithic better?

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  • Android onActivityResult is always 0

    - by Dean
    This has been killing me for two days now. I have a main Activity A which calls a second Activity B. Activity B simply presents the user with a listview. When I press an item on the list view I want a couple of strings to be passed back to the main Activity A and Activiy B will finish. The problem is I always get a resultcode of 0 and the data bundle is null. I really don't understand why this is happening. Here is my code. Start Activity B for result; Test.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent i = new Intent(recipeActivity.this, BrowseLoadRecipes.class); startActivityForResult(i, RECIPE_CHOOSER); } }); This starts the second Activity fine. Activity B populates a listview and when I click an item I'm trying to send some data back to the calling Activity A. Any text at the moment, so I used the following in Activity B; lv.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> a, View v, int position, long id) { Bundle bundle = new Bundle(); bundle.putString("TEXT", "Please work... pleeeeaasee"); Intent mIntent = new Intent(); mIntent.putExtras(bundle); setResult(RESULT_OK, mIntent); finish(); } }); In the calling activity I have the following listening for the return as follows; protected void onActivityResult(int requestCode, int resultCode, Intent data) { switch(requestCode) { //TODO case RECIPE_CHOOSER: Toast.makeText(getApplicationContext(), "In recipe return", Toast.LENGTH_SHORT).show(); Toast.makeText(getApplicationContext(), "resultCode is " + String.valueOf(resultCode), Toast.LENGTH_SHORT).show(); if (resultCode == RESULT_OK) { Bundle b = getIntent().getExtras(); Toast.makeText(getApplicationContext(), "Returned " + b.getString("TEXT"), Toast.LENGTH_LONG).show(); } if (resultCode == RESULT_CANCELED) { } break; } } } I can see that the request code is correctly returned, but the resultcode is always a 0 and the data is always a null. I've ran through the debug and the setResult is doing its job and the bundle does indeed have the data I'm passing, but it's lost at some point along the way. Is there something in the manifest I'm missing or something. It's killed my progress on this project so far. Any help would truly be appreciated. Thanks, Dean

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  • How do you unit test the real world?

    - by Kim Sun-wu
    I'm primarily a C++ coder, and thus far, have managed without really writing tests for all of my code. I've decided this is a Bad Idea(tm), after adding new features that subtly broke old features, or, depending on how you wish to look at it, introduced some new "features" of their own. But, unit testing seems to be an extremely brittle mechanism. You can test for something in "perfect" conditions, but you don't get to see how your code performs when stuff breaks. A for instance is a crawler, let's say it crawls a few specific sites, for data X. Do you simply save sample pages, test against those, and hope that the sites never change? This would work fine as regression tests, but, what sort of tests would you write to constantly check those sites live and let you know when the application isn't doing it's job because the site changed something, that now causes your application to crash? Wouldn't you want your test suite to monitor the intent of the code? The above example is a bit contrived, and something I haven't run into (in case you haven't guessed). Let me pick something I have, though. How do you test an application will do its job in the face of a degraded network stack? That is, say you have a moderate amount of packet loss, for one reason or the other, and you have a function DoSomethingOverTheNetwork() which is supposed to degrade gracefully when the stack isn't performing as it's supposed to; but does it? The developer tests it personally by purposely setting up a gateway that drops packets to simulate a bad network when he first writes it. A few months later, someone checks in some code that modifies something subtly, so the degradation isn't detected in time, or, the application doesn't even recognize the degradation, this is never caught, because you can't run real world tests like this using unit tests, can you? Further, how about file corruption? Let's say you're storing a list of servers in a file, and the checksum looks okay, but the data isn't really. You want the code to handle that, you write some code that you think does that. How do you test that it does exactly that for the life of the application? Can you? Hence, brittleness. Unit tests seem to test the code only in perfect conditions(and this is promoted, with mock objects and such), not what they'll face in the wild. Don't get me wrong, I think unit tests are great, but a test suite composed only of them seems to be a smart way to introduce subtle bugs in your code while feeling overconfident about it's reliability. How do I address the above situations? If unit tests aren't the answer, what is? Thanks!

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  • how to set objectForKey to UISwitch to access switch for save selected option

    - by Rkm
    SystemUIViewcontroller has button event. Tap on Button fire InfoTableviewController. InfoTableview has UISwitch. How to set objectForKey to Info to access UIswitch ViewDidload of System... - (void)viewDidLoad { [super viewDidLoad]; self.Infoarray = [NSMutableArray array]; Info *info = [[Info alloc]initWithNibName:@"Info" bundle:nil]; [self.Infoarray addObject:[NSDictionary dictionaryWithObjectsAndKeys:info, @"viewController", nil]]; } SystemUIviewcontroller button event... -(IBAction) Info_Button_Clicked:(id) sender { Info *info = [[Info alloc]initWithNibName:@"Info" bundle:[NSBundle mainBundle]]; [self.navigationController pushViewController:info animated:YES]; [info release]; } Here for Info TableviewController... - (void)viewDidLoad { [super viewDidLoad]; self.Soundarray = [NSArray arrayWithObjects: [NSDictionary dictionaryWithObjectsAndKeys: @"Sounds", @"labelKey", self.SoundsswitchCtl, @"viewKey", nil],nil]; } // Customize the appearance of table view cells. - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { UITableViewCell *cell = nil; if ([indexPath section] == 0) { static NSString *kDisplayCell_ID = @"DisplayCellID"; cell = [self.tableView dequeueReusableCellWithIdentifier: kDisplayCell_ID]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier: kDisplayCell_ID] autorelease]; cell.selectionStyle = UITableViewCellSelectionStyleNone; } else { // the cell is being recycled, remove old embedded controls UIView *viewToRemove = nil; viewToRemove = [cell.contentView viewWithTag:1]; if (viewToRemove) [viewToRemove removeFromSuperview]; } cell.textLabel.text = [[self.Soundarray objectAtIndex: indexPath.row] valueForKey:@"labelKey"]; UIControl *control = [[self.Soundarray objectAtIndex: indexPath.row] valueForKey:@"viewKey"]; [cell.contentView addSubview:control]; return cell; } } - (UISwitch *)SoundsswitchCtl { if (SoundsswitchCtl == nil) { CGRect frame = CGRectMake(198.0, 12.0, 94.0, 27.0); SoundsswitchCtl = [[UISwitch alloc] initWithFrame:frame]; [SoundsswitchCtl addTarget:self action:@selector(switch_Sounds:) forControlEvents:UIControlEventValueChanged]; // in case the parent view draws with a custom color or gradient, use a transparent color SoundsswitchCtl.backgroundColor = [UIColor clearColor]; [SoundsswitchCtl setAccessibilityLabel:NSLocalizedString(@"StandardSwitch", @"")]; SoundsswitchCtl.tag = 1; // tag this view for later so we can remove it from recycled table cells } return SoundsswitchCtl; }

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  • Safely escaping and reading back a file path in ruby

    - by user336851
    I need to save a few informations about some files. Nothing too fancy so I thought I would go with a simple one line per item text file. Something like this : # write io.print "%i %s %s\n" % [File.mtime(fname), fname, Digest::SHA1.file(fname).hexdigest] # read io.each do |line| mtime, name, hash = line.scanf "%i %s %s" end Of course this doesn't work because a file name can contain spaces (breaking scanf) and line breaks (breaking IO#each). The line break problem can be avoided by dropping the use of each and going with a bunch of gets(' ') while not io.eof? mtime = Time.at(io.gets(" ").to_i) name = io.gets " " hash = io.gets "\n" end Dealing with spaces in the names is another matter. Now we need to do some escaping. note : I like space as a record delimiter but I'd have no issue changing it for one easier to use. In the case of filenames though, the only one that could help is ascii nul "\0" but a nul delimited file isn't really a text file anymore... I initially had a wall of text detailing the iterations of my struggle to make a correct escaping function and its reciprocal but it was just boring and not really useful. I'll just give you the final result: def write_name(io, val) io << val.gsub(/([\\ ])/, "\\\\\\1") # yes that' 6 backslashes ! end def read_name(io) name, continued = "", true while continued continued = false name += io.gets(' ').gsub(/\\(.)/) do |c| if c=="\\\\" "\\" elsif c=="\\ " continued=true " " else raise "unexpected backslash escape : %p (%s %i)" % [c, io.path, io.pos] end end end return name.chomp(' ') end I'm not happy at all with read_name. Way too long and akward, I feel it shouldn't be that hard. While trying to make this work I tried to come up with other ways : the bittorrent encoded / php serialize way : prefix the file name with the length of the name then just io.read(name_len.to_i). It works but it's a real pita to edit the file by hand. At this point we're halfway to a binary format. String#inspect : This one looks expressly made for that purpose ! Except it seems like the only way to get the value back is through eval. I hate the idea of eval-ing a string I didn't generate from trusted data. So. Opinions ? Isn't there some lib which can do all this ? Am I missing something obvious ? How would you do that ?

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  • Specializing a template on a lambda in C++0x

    - by Tony A.
    I've written a traits class that lets me extract information about the arguments and type of a function or function object in C++0x (tested with gcc 4.5.0). The general case handles function objects: template <typename F> struct function_traits { template <typename R, typename... A> struct _internal { }; template <typename R, typename... A> struct _internal<R (F::*)(A...)> { // ... }; typedef typename _internal<decltype(&F::operator())>::<<nested types go here>>; }; Then I have a specialization for plain functions at global scope: template <typename R, typename... A> struct function_traits<R (*)(A...)> { // ... }; This works fine, I can pass a function into the template or a function object and it works properly: template <typename F> void foo(F f) { typename function_traits<F>::whatever ...; } int f(int x) { ... } foo(f); What if, instead of passing a function or function object into foo, I want to pass a lambda expression? foo([](int x) { ... }); The problem here is that neither specialization of function_traits<> applies. The C++0x draft says that the type of the expression is a "unique, unnamed, non-union class type". Demangling the result of calling typeid(...).name() on the expression gives me what appears to be gcc's internal naming convention for the lambda, main::{lambda(int)#1}, not something that syntactically represents a C++ typename. In short, is there anything I can put into the template here: template <typename R, typename... A> struct function_traits<????> { ... } that will allow this traits class to accept a lambda expression?

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  • CSS Graph- Bars not showing correctly

    - by Olivia
    I'm trying to create a CSS/HTML based graph using this tutorial here. However instead of putting the data directly into the html code I'm importing it from a CSV file using PHP with the following code. <?PHP /* Open CSV file */ $handle = fopen("defects.csv", "r"); $c = 0; /* gets data from csv file */ while (($data = fgetcsv($handle, 1000, ",")) !== FALSE) { /* stores dates as variable $date */ $date[$c] = $data[0]; $c++; /* inserts defect data into html code */ echo "<dd class=\"p" . $data[2] . "\"><span><b>" . $data[2] . "</b></span></dd>"; echo "<dd class=\"sub p" . $data[3] . "\" ><span><b>" . $data[3] . "</b></span></dd>"; } echo "</dl>"; echo "<ul class=\"xAxis\">"; /* X AXIS */ /* inserts date data into html code for x axis */ for ($d=0; $d < $c; $d++) { echo "<li>" . $date[$d] . "</li>"; } ?> The values are being placed correctly on the chart, but the bars aren't appearing. The CSS code I have for the bars is: /* default column styling */ dl#csschart span{ height:50%; background:url(../images/barx.png) repeat-y; } dl#csschart .sub{ margin-left:-33px; } dl#csschart .sub span{ background:url(../images/subBarx.png) repeat-y; } Just in case it helps, I've print screened how the graph should look. You can see it at: http://allured.info/graph/failgraph.png

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  • Multiple layouts in rails [Newbie Q]

    - by BriteLite
    Hi. As a newb, I decided to build a "home inventory" application. I am now stuck on how to programmatically select a layout based on what type of item it is when viewing it in a browser. According to my planning, so far I should have created a few models to represent types of items I can find in my home: Furniture, Electronics and Books. class Book < ActiveRecord::Base end class Furniture < ActiveRecord::Base end class Electronic < ActiveRecord::Base end Now the Books model has things like isbn, pages, address, and category. Furniture model has things like color, price, address, and category. Electronics has things like name, voltage, address, and category. Here is where I got confused. I know the property address is going to be the same for all of them. I also know that, I will need to create multiple "layouts" for 3 different types of items to show the different properties of said items with appropriate graphics and stylesheets. But how will I go about deciding which category the item is so I can determine which layout to render. According to me, this is how I will do it: class DisplayController < ApplicationController def display @item = Params[:item] if @item.category = "electronics" render :layout => 'electronics' end end In my routes.rb map.display ':item', :controller => 'display', :action => 'display' I only seem to have one concern with this, I probably will add a lot of categories later on and think there should be a more DRY-esque way of dealing, rather than hardcoding them. I understand that I need to add into my layout html tags to display relevant information for that particular category. ----Questions---- Is this the right way to approach this type of problem. Will this approach be compatible when I decide to add a gem like *thinking_sphinx* to run search. What issues do you see with my approach and how can I make it better. I was reading something about "Polymorphic Assoc", does that apply in this case, since category exist for all items? Also, I was trying to get a routes to render a URL like "http://localhost/living-room-tv"

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  • Avoiding explicit recursion in Haskell

    - by Travis Brown
    The following simple function applies a given monadic function iteratively until it hits a Nothing, at which point it returns the last non-Nothing value. It does what I need, and I understand how it works. lastJustM :: (Monad m) => (a -> m (Maybe a)) -> a -> m a lastJustM g x = g x >>= maybe (return x) (lastJustM g) As part of my self-education in Haskell I'm trying to avoid explicit recursion (or at least understand how to) whenever I can. It seems like there should be a simple non-explicitly recursive solution in this case, but I'm having trouble figuring it out. I don't want something like a monadic version of takeWhile, since it could be expensive to collect all the pre-Nothing values, and I don't care about them anyway. I checked Hoogle for the signature and nothing shows up. The m (Maybe a) bit makes me think a monad transformer might be useful here, but I don't really have the intuitions I'd need to come up with the details (yet). It's probably either embarrassingly easy to do this or embarrassingly easy to see why it can't or shouldn't be done, but this wouldn't be the first time I've used self-embarrassment as a pedagogical strategy. Background: Here's a simplified working example for context: suppose we're interested in random walks in the unit square, but we only care about points of exit. We have the following step function: randomStep :: (Floating a, Ord a, Random a) => a -> (a, a) -> State StdGen (Maybe (a, a)) randomStep s (x, y) = do (a, gen') <- randomR (0, 2 * pi) <$> get put gen' let (x', y') = (x + s * cos a, y + s * sin a) if x' < 0 || x' > 1 || y' < 0 || y' > 1 then return Nothing else return $ Just (x', y') Something like evalState (lastJustM (randomStep 0.01) (0.5, 0.5)) <$> newStdGen will give us a new data point.

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  • C - How to use both aio_read() and aio_write().

    - by Slav
    I implement game server where I need to both read and write. So I accept incoming connection and start reading from it using aio_read() but when I need to send something, I stop reading using aio_cancel() and then use aio_write(). Within write's callback I resume reading. So, I do read all the time but when I need to send something - I pause reading. It works for ~20% of time - in other case call to aio_cancel() fails with "Operation now in progress" - and I cannot cancel it (even within permanent while cycle). So, my added write operation never happens. How to use these functions well? What did I missed? EDIT: Used under Linux 2.6.35. Ubuntu 10 - 32 bit. Example code: void handle_read(union sigval sigev_value) { /* handle data or disconnection */ } void handle_write(union sigval sigev_value) { /* free writing buffer memory */ } void start() { const int acceptorSocket = socket(AF_INET, SOCK_STREAM, 0); struct sockaddr_in addr; memset(&addr, 0, sizeof(struct sockaddr_in)); addr.sin_family = AF_INET; addr.sin_addr.s_addr = INADDR_ANY; addr.sin_port = htons(port); bind(acceptorSocket, (struct sockaddr*)&addr, sizeof(struct sockaddr_in)); listen(acceptorSocket, SOMAXCONN); struct sockaddr_in address; socklen_t addressLen = sizeof(struct sockaddr_in); for(;;) { const int incomingSocket = accept(acceptorSocket, (struct sockaddr*)&address, &addressLen); if(incomingSocket == -1) { /* handle error ... */} else { //say socket to append outcoming messages at writing: const int currentFlags = fcntl(incomingSocket, F_GETFL, 0); if(currentFlags < 0) { /* handle error ... */ } if(fcntl(incomingSocket, F_SETFL, currentFlags | O_APPEND) == -1) { /* handle another error ... */ } //start reading: struct aiocb* readingAiocb = new struct aiocb; memset(readingAiocb, 0, sizeof(struct aiocb)); readingAiocb->aio_nbytes = MY_SOME_BUFFER_SIZE; readingAiocb->aio_fildes = socketDesc; readingAiocb->aio_buf = mySomeReadBuffer; readingAiocb->aio_sigevent.sigev_notify = SIGEV_THREAD; readingAiocb->aio_sigevent.sigev_value.sival_ptr = (void*)mySomeData; readingAiocb->aio_sigevent.sigev_notify_function = handle_read; if(aio_read(readingAiocb) != 0) { /* handle error ... */ } } } } //called at any time from server side: send(void* data, const size_t dataLength) { //... some thread-safety precautions not needed here ... const int cancellingResult = aio_cancel(socketDesc, readingAiocb); if(cancellingResult != AIO_CANCELED) { //this one happens ~80% of the time - embracing previous call to permanent while cycle does not help: if(cancellingResult == AIO_NOTCANCELED) { puts(strerror(aio_return(readingAiocb))); // "Operation now in progress" /* don't know what to do... */ } } //otherwise it's okay to send: else { aio_write(...); } }

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  • Why sockets does not die when server dies? Why socket dies when server is alive?

    - by Roman
    I try to play with sockets a bit. For that I wrote very simple "client" and "server" applications. Client: import java.net.*; public class client { public static void main(String[] args) throws Exception { InetAddress localhost = InetAddress.getLocalHost(); System.out.println("before"); Socket clientSideSocket = null; try { clientSideSocket = new Socket(localhost,12345,localhost,54321); } catch (ConnectException e) { System.out.println("Connection Refused"); } System.out.println("after"); if (clientSideSocket != null) { clientSideSocket.close(); } } } Server: import java.net.*; public class server { public static void main(String[] args) throws Exception { ServerSocket listener = new ServerSocket(12345); while (true) { Socket serverSideSocket = listener.accept(); System.out.println("A client-request is accepted."); } } } And I found a behavior that I cannot explain: I start a server, than I start a client. Connection is successfully established (client stops running and server is running). Then I close the server and start it again in a second. After that I start a client and it writes "Connection Refused". It seems to me that the server "remember" the old connection and does not want to open the second connection twice. But I do not understand how it is possible. Because I killed the previous server and started a new one! I do not start the server immediately after the previous one was killed (I wait like 20 seconds). In this case the server "forget" the socket from the previous server and accepts the request from the client. I start the server and then I start the client. Connection is established (server writes: "A client-request is accepted"). Then I wait a minute and start the client again. And server (which was running the whole time) accept the request again! Why? The server should not accept the request from the same client-IP and client-port but it does!

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  • How can I execute an insert with data from a repeater-generated form whose data source is SQL?

    - by Duke
    I'm storing multilingual data in a database whose model is language normalized (like this). For this particular problem the key for the table in question consists of a value entered by the user and a language from the language table. I'd like to dynamically generate a form with input fields for all available languages. The user inputs a key value then goes down a list of field sets filling out the information in each language. In this case there are two fields for every language, a name and a value (the value is language dependent.) I have all existing information displayed on the page with a gridview, below which I have a formview that is always in insert mode allowing the user to enter new data. Within the formview I have a repeater with an SQLDataSource that gets a list of available languages: <asp:Repeater ID="SessionLocaleRepeater" runat="server" DataSourceID="LocaleSQLDataSource" EnableViewState="false"> <ItemTemplate> <tr> <th scope="row"><%# DataBinder.Eval(Container.DataItem, "LocaleName") %></th> <td>Name:</td> <td><asp:TextBox ID="TextBox1" runat="server" Text="" /></td> <td>Number:</td> <td><asp:TextBox ID="TextBox2" runat="server" Text="" /></td> </tr> </ItemTemplate> </asp:Repeater> I figured that in order to insert this data I'd have to execute my sql server insert stored procedure for each item in the repeater; I am trying to use the formview inserting event. The problem is that the repeater isn't databound to the SQLDataSource until after the formview inserting event (inserting event is in PostBackEvent and databind is in PreRender), which means the controls and data are not available when the inserting event is fired. I tried databinding the repeater during the formview inserting event; the controls were available but the data was not. Would this have something to do with how/when the viewstate information is re-added to the controls? From what I've read, Viewstate is one of the first things to be restored. Given the order of events how can I get the data I need for the insert? I'm open to other solutions to creating dynamic input controls, but they will have to query the database to determine how many sets of controls to create.

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