ClientAbortException Problem

Hi to all
I am developing one application that has to upload any type of file in to data base. i used BLOB in db. thats working fine. but its not uploading large amount of files. i used
PreparedStatement ps = con.prepareStatement("INSERT INTO resume VALUES(?,?)"); File file = new File(path1); FileInputStream fs = new FileInputStream(file); ps.setString(1,id); ps.setBinaryStream(2,fs,fs.available()); int i = ps.executeUpdate(); if(i!=0) out.println("<h2> Resume Upload Successfully</h2>"); else out.println("<h2>Problem In Resume Upload");
when i am trying to upload large file whose characters are 195085.( i got this value by printing fs.available() ) it is giving following error.
Failed Due To ClientAbortException: java.net.SocketException: Connection reset by peer: socket write error
It is uploading small size files upto 50000 (i guess thats max size) .
Please help me out from this error. my program has to upload all size files in DB. please Help me. thanks in advance.

praveen_nlg wrote:
Hi jschell ..
Thanks for your response. that's working fine now. the problem is not with the code, but with my Database. i restarted my db service. now its uploading upto 4 gb. Note that that is a very unusual solution however given what you have posted here.

Similar Messages

ClientAbortException problem on error page

Hi
I am trying to solve the mistery that has been bugging me for a while now.
We have the same J2EE app deployed on 4 servers. The application is for content management.
One server is for development, one for QA, and other 2 for production. All servers have same hardware and same software installed. All servers rund the same J2EE SDK with Sun's App Server 8.1PE...
Now, the mistery....I only get the follwoing exception on the 2 production serversThe error page works fine on other servers and it is the same JSP page on all servers....I cannot figure out why I am getting this error and what is the error supposed to mean..
[#|2004-09-02T08:23:56.703-0400|SEVERE|sun-appserver-pe8.0|javax.enterprise.system.container.web|_Th
readID=11;|org.apache.catalina.core.StandardHostValve@ce41cc: Exception Processing ErrorPage[errorCode=404, location=/error404.jsp]
ClientAbortException: java.net.SocketException: Connection reset by peer: socket write error
        at org.apache.coyote.tomcat5.OutputBuffer.realWriteBytes(OutputBuffer.java:421)
        at org.apache.tomcat.util.buf.ByteChunk.flushBuffer(ByteChunk.java:444)
        at org.apache.coyote.tomcat5.OutputBuffer.doFlush(OutputBuffer.java:363)
        at org.apache.coyote.tomcat5.OutputBuffer.flush(OutputBuffer.java:345)
        at org.apache.coyote.tomcat5.CoyoteResponse.flushBuffer(CoyoteResponse.java:559)
        at org.apache.coyote.tomcat5.CoyoteResponseFacade$1.run(CoyoteResponseFacade.java:259)
        at java.security.AccessController.doPrivileged(Native Method)
        at org.apache.coyote.tomcat5.CoyoteResponseFacade.flushBuffer(CoyoteResponseFacade.java:254)
        at org.apache.catalina.core.StandardHostValve.status(StandardHostValve.java:362)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:210)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:156)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:180)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:154)
        at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:582)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:154)
        at com.sun.enterprise.webservice.EjbWebServiceValve.invoke(EjbWebServiceValve.java:134)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:154)
        at com.sun.enterprise.security.web.SingleSignOn.invoke(SingleSignOn.java:254)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:154)
        at com.sun.enterprise.web.VirtualServerValve.invoke(VirtualServerValve.java:209)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:154)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:569)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:161)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:156)
        at com.sun.enterprise.web.VirtualServerMappingValve.invoke(VirtualServerMappingValve.java:16
6)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:154)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:569)
        at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:979)
        at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:211)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:692)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11P
rotocol.java:647)
        at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:589)
        at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:691)
        at java.lang.Thread.run(Thread.java:534)
|#]

Hi. I am also same kind of problem. I ahve a simple JSP in my Struts 2 Application. Server used is weblogic. As soon as i click on the Calender Image. The Socket write erro is thrown. I a m not able to under stand as to why socket write error is happening, as inly a simple javascript function call happens on click of that image.
JSP Cal code:
value="<s:date name='remitFileSetup.effcvStartDt' format='MM/dd/yyyy'/>" size='10' maxlength='10'/><a id="Date1" href="#"><img onclick="javascript:callSelf('Date1','startdate','true','divMesReg1')" valign="bottom" src="<s:url value="/images/cal.gif"/>"
method implementation:
function call(cButton, cOutput, cSingle,divId) {
var MA = [];
     //alert("HI 1");
     //to convert cSingle into boolean
     if(cSingle=='false')
     cSingle=false;
else{
          cSingle=true;
function closed(cal) {
// here we'll write the output; this is only for example. You
// will normally fill an input field or something with the dates.
var el = document.getElementById(cOutput);
// reset initial content.
//el.innerHTML = "";
          if(cSingle==true) {
               el.value="";
// Reset the "MA", in case one triggers the calendar again.
// CAREFUL! You don't want to do "MA = [];". We need to modify
// the value of the current array, instead of creating a new one.
// Calendar.setup is called only once! :-) So be careful.
MA.length = 0;
// walk the calendar's multiple dates selection hash
for (var i in cal.multiple) {
var d = cal.multiple;
//alert("HI 2");
// sometimes the date is not actually selected, that's why we need to check.
if (d) {
//this is to check that the newly selected date is not a repetition of of the date already
// selected in the textbox
var tempOlddate=trim(el.value);
var flagTest="true";
if(tempOlddate.indexOf(d.print("%m/%d/%Y"))==-1)
var tmpoldDt=el.value;
     // OK, selected. Fill an input field. Or something. Just for example,
// we will display all selected dates in the element having the id "output".
var x=el.value;
var y= x.substring(x.length-2,x.length);
//alert(y);
//alert("n"+y.indexOf("\n"));
//alert("br"+y.indexOf("<br />"));
if(trim(y)=="" )
     el.value +=d.print("%m/%d/%Y") + "<br />";
else if(y.indexOf("\n")!= -1 )
     el.value +=d.print("%m/%d/%Y") + "<br />";
          else if(y.indexOf("/>")!=-1)
     el.value +=d.print("%m/%d/%Y") + "<br />";
          else{
     el.value +="<br />"+ d.print("%m/%d/%Y") + "<br />";
// and push it in the "MA", in case one triggers the calendar again.
MA[MA.length] = d;
     var vararray= new Array();
var temp= el.value;
     vararray = temp.split("<br />");
     el.value="";
     for(i=0; i<vararray.length-1; i++) {
el.value+=vararray[i];
if(i < vararray.length) {
     el.value+="\n";
     if(cSingle==true) {
          if(vararray.length>2){
               //alert('User cant select more than one date.');
               document.getElementById(divId).style.display="inline";
               el.value="";
     else {
          document.getElementById(divId).style.display="none";
cal.hide();
return true;
     //alert("HI 4");
Calendar.setup({
align : "BR",
showOthers : true,
multiple : MA, // pass the initial or computed array of multiple dates to be initially selected
onClose : closed,
button : cButton,
singleMulti : cSingle
     //alert("HI 3");
ERROR:
org.apache.struts2.views.jsp.ComponentTagSupport.doStartTag(ComponentTagSupport.java:54)
     at jsp_servlet.__404._jsp__tag4(__404.java:270)
     at jsp_servlet.__404._jspService(__404.java:135)
     at weblogic.servlet.jsp.JspBase.service(JspBase.java:34)
     at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227)
     at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)
     at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:283)
     at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:175)
     at weblogic.servlet.internal.RequestDispatcherImpl.invokeServlet(RequestDispatcherImpl.java:530)
     at weblogic.servlet.internal.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:266)
     at weblogic.servlet.internal.ServletResponseImpl.sendError(ServletResponseImpl.java:710)
     at weblogic.servlet.internal.ServletResponseImpl.sendError(ServletResponseImpl.java:559)
     at weblogic.servlet.FileServlet.findSource(FileServlet.java:265)
     at weblogic.servlet.FileServlet.doGetHeadPost(FileServlet.java:188)
     at weblogic.servlet.FileServlet.service(FileServlet.java:170)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
     at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227)
     at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)
     at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:283)
     at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:26)
     at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:42)
     at org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:413)
     at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:42)
     at org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter.doFilterInternal(OpenEntityManagerInViewFilter.java:111)
     at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:75)
     at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:42)
     at org.apache.struts2.dispatcher.ActionContextCleanUp.doFilter(ActionContextCleanUp.java:99)
     at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:42)
     at javawebparts.filter.AppAvailabilityFilter.doFilter(AppAvailabilityFilter.java:485)
     at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:42)
     at weblogic.servlet.internal.RequestEventsFilter.doFilter(RequestEventsFilter.java:26)
     at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:42)
     at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3242)
     at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
     at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:121)
     at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2010)
     at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:1916)
     at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1366)
     at weblogic.work.ExecuteThread.execute(ExecuteThread.java:209)
     at weblogic.work.ExecuteThread.run(ExecuteThread.java:181)

ClientAbortException - problem weired.

Hi all ,
I have a chaching servlet and a compression filter servlet. the compression filter servlet througs up ClientAbortException . what could be the reason.
I know that this exception is thrown when the user closes the browser when the responses is sent of stop the action through browser. but in my case nothing is the case.
I am using tomcat 5.x server.
Regards,
krthekeyan.s

praveen_nlg wrote:
Hi jschell ..
Thanks for your response. that's working fine now. the problem is not with the code, but with my Database. i restarted my db service. now its uploading upto 4 gb. Note that that is a very unusual solution however given what you have posted here.

Problem with socket_timeout

Hi all !
I'm using Tomcat 5x on windows 2003 (64bit) as Application server. When I run application ,I receive 'error sending data, aborting: ClientAbortException: java.net.SocketException: Software caused connection abort: socket write error' . And I know that I need to increase 'socket_timeout' but I know where 'socket_timeout' is in Tomcat .
Thanks for any help !!
Tien Lai

I've read your post about socket error in this forum.Good.
But I don't know how to solve this problem. Then either you haven't read it at all or you haven't understood it. I said above that it's a network hardware problem, as does the link I gave you, several times. You can't solve network hardware problems. The network hardware guys do that.

ClientAbortException

I have received this message several times through CFERROR.
The cause of this output exception was that: ClientAbortException: java.net.SocketException: Connection reset by peer: socket write error.
How can I fix this?

I believe your problem is the same as described in this link.
http://www.jjask.com/360015/connection-reset-socket-write-error-cfcontent-coldfusion
I recommend you check how is being done to build the content. See what can be done to optimize module that uses this service. Reinstall not believe solve because before this error was sent to the server.log and now he shoots at the screen which to me is one of the things that came embedding tomcat in coldfusion. I did not had this problem in applications migrated but I confess that neither uses cfcontent very heavy and only way to load images and download pdfs.
I believe that even if you reinstall this error is inherent to its Application. Review application is something that can solve the problem.
Hope this helps

How to Ignore ClientAbortException

Dear All,
I've a JSF Application running on Jboss4(Tomcat5). My problem is that I've a page that when loaded sends multiple parallel AJAX requests to the server. Tomcat most of the times throws following exception while loading the page
ClientAbortException: java.net.SocketException: Connection reset
at org.apache.catalina.connector.OutputBuffer.doFlush(OutputBuffer.java:327)
at org.apache.catalina.connector.OutputBuffer.flush(OutputBuffer.java:293)
at org.apache.catalina.connector.Response.flushBuffer(Response.java:537)
at org.apache.catalina.core.StandardHostValve.status(StandardHostValve.java:286)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:136)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.jboss.web.tomcat.tc5.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:156)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.MasterSlaveWorkerThread.run(MasterSlaveWorkerThread.java:112)
at java.lang.Thread.run(Thread.java:595)
Caused by: java.net.SocketException: Connection reset
at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:96)
at java.net.SocketOutputStream.write(SocketOutputStream.java:136)
at com.sun.net.ssl.internal.ssl.OutputRecord.writeBuffer(OutputRecord.java:283)
at com.sun.net.ssl.internal.ssl.OutputRecord.write(OutputRecord.java:272)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.writeRecord(SSLSocketImpl.java:663)
at com.sun.net.ssl.internal.ssl.AppOutputStream.write(AppOutputStream.java:59)
at org.apache.coyote.http11.InternalOutputBuffer.realWriteBytes(InternalOutputBuffer.java:746)
at org.apache.tomcat.util.buf.ByteChunk.flushBuffer(ByteChunk.java:433)
at org.apache.coyote.http11.InternalOutputBuffer.flush(InternalOutputBuffer.java:304)
at org.apache.coyote.http11.Http11Processor.action(Http11Processor.java:991)
at org.apache.coyote.Response.action(Response.java:182)
at org.apache.catalina.connector.OutputBuffer.doFlush(OutputBuffer.java:322)
Is there any way I can tell Tomcat to ignore this exception or atleast not to throw the stack trace on console.

Any one have any idea of this issue ?

ClientAbortException..help

Hi
I am writing a struts appliction a to download a file that is on the server. When the user clicks the download button, its displaying the open,save cancel window. Open and save are working fine, but while downloading a word doc or pdf, when the user clicks cancel, its displaying a ClientAbort Exception.
ClientAbortException: java.net.SocketException: Connection reset by peer: socket write error
Oct 9, 2006 11:08:25 AM org.apache.struts.action.RequestProcessor processException
WARNING: Unhandled Exception thrown: class org.apache.catalina.connector.ClientAbortException
While downloading a image, if user clicks cancel, its working fine.
Please help me how to avoid this situation.

I am facing the same problem.
Can you tell how did you resolve it?

Org.apache.catalina.connector.ClientAbortException

HI
How to catch ClientAbortException, when I am adding the following line it is showing error. Its not identifying the org.apache.catalina, do I need to add any jar files to my path to identify this exception Please respond..
org.apache.catalina.connector.ClientAbortException

I am facing the same problem.
Can you tell how did you resolve it?

A problem with threads

I am trying to implement some kind of a server listening for requests. The listener part of the app, is a daemon thread that listens for connections and instantiates a handling daemon thread once it gets some. However, my problem is that i must be able to kill the listening thread at the user's will (say via a sto button). I have done this via the Sun's proposed way, by testing a boolean flag in the loop, which is set to false when i wish to kill the thread. The problem with this thing is the following...
Once the thread starts excecuting, it will test the flag, find it true and enter the loop. At some point it will LOCK on the server socket waiting for connection. Unless some client actually connects, it will keep on listening indefinatelly whithought ever bothering to check for the flag again (no matter how many times you set the damn thing to false).
My question is this: Is there any real, non-theoretical, applied way to stop thread in java safely?
Thank you in advance,
Lefty

This was one solution from the socket programming forum, have you tried this??
public Thread MyThread extends Thread{
     boolean active = true;
     public void run(){
          ss.setSoTimeout(90);
          while (active){
               try{
                    serverSocket = ss.accept();
               catch (SocketTimeoutException ste){
               // do nothing
     // interrupt thread
     public void deactivate(){
          active = false;
          // you gotta sleep for a time longer than the
          // accept() timeout to make sure that timeout is finished.
          try{
               sleep(91);
          }catch (InterruptedException ie){
          interrupt();
}

A problem with Threads and MMapi

I am tring to execute a class based on Game canvas.
The problem begin when I try to Play both a MIDI tone and to run an infinit Thread loop.
The MIDI tone "Stammers".
How to over come the problem?
Thanks in advance
Kobi
See Code example below:
import java.io.IOException;
import java.io.InputStream;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Image;
import javax.microedition.lcdui.game.GameCanvas;
import javax.microedition.media.Manager;
import javax.microedition.media.MediaException;
import javax.microedition.media.Player;
public class MainScreenCanvas extends GameCanvas implements Runnable {
     private MainMIDlet parent;
     private boolean mTrucking = false;
     Image imgBackgound = null;
     int imgBackgoundX = 0, imgBackgoundY = 0;
     Player player;
     public MainScreenCanvas(MainMIDlet parent)
          super(true);
          this.parent = parent;
          try
               imgBackgound = Image.createImage("/images/area03_bkg0.png");
               imgBackgoundX = this.getWidth() - imgBackgound.getWidth();
               imgBackgoundY = this.getHeight() - imgBackgound.getHeight();
          catch(Exception e)
               System.out.println(e.getMessage());
      * starts thread
     public void start()
          mTrucking = true;
          Thread t = new Thread(this);
          t.start();
      * stops thread
     public void stop()
          mTrucking = false;
     public void play()
          try
               InputStream is = getClass().getResourceAsStream("/sounds/scale.mid");
               player = Manager.createPlayer(is, "audio/midi");
               player.setLoopCount(-1);
               player.prefetch();
               player.start();
          catch(Exception e)
               System.out.println(e.getMessage());
     public void run()
          Graphics g = getGraphics();
          play();
          while (true)
               tick();
               input();
               render(g);
      * responsible for object movements
     private void tick()
      * response to key input
     private void input()
          int keyStates = getKeyStates();
          if ((keyStates & LEFT_PRESSED) != 0)
               imgBackgoundX++;
               if (imgBackgoundX > 0)
                    imgBackgoundX = 0;
          if ((keyStates & RIGHT_PRESSED) != 0)
               imgBackgoundX--;
               if (imgBackgoundX < this.getWidth() - imgBackgound.getWidth())
                    imgBackgoundX = this.getWidth() - imgBackgound.getWidth();
      * Responsible for the drawing
      * @param g
     private void render(Graphics g)
          g.drawImage(imgBackgound, imgBackgoundX, imgBackgoundY, Graphics.TOP | Graphics.LEFT);
          this.flushGraphics();
}

You can also try to provide a greater Priority to your player thread so that it gains the CPU time when ever it needs it and don't harm the playback.
However a loop in a Thread and that to an infinite loop is one kind of very bad programming, 'cuz the loop eats up most of your CPU time which in turn adds up more delays of the execution of other tasks (just as in your case it is the playback). By witting codes bit efficiently and planning out the architectural execution flow of the app before start writing the code helps solve these kind of issues.
You can go through [this simple tutorial|http://oreilly.com/catalog/expjava/excerpt/index.html] about Basics of Java and Threads to know more about threads.
Regds,
SD
N.B. And yes there are more articles and tutorials available but much of them targets the Java SE / EE, but if you want to read them here is [another great one straight from SUN|http://java.sun.com/docs/books/tutorial/essential/concurrency/index.html] .
Edited by: find_suvro@SDN on 7 Nov, 2008 12:00 PM

J2ME problem with threads

Hi all,
I would like to ask you for a help. I need to write a small program at my university. I started to write a midlet which function would be to countdown time for sports activities. I woul like to start a new thread - the one that counts down - and at the same time make the main thread sleep. After the "countdown" thread finishes, the main thread wakes up and waits for user input. The problem is that when the "countdown" thread finishes his work, I've got Uncaught exception java/lang/NullPointerException. error and the midlet halts.
Below you can find the code
import java.lang.*;
import java.util.*;
import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;
public class intervals extends MIDlet implements CommandListener
public Display ekran;
private SweepCanvas sweeper;
private Form rundy;
private TextField round0, round1, round2, round3, round4, round5, round6, round7, round8;
private long czas,x;
private Command exitCommand;
private Command addRound;
private Command delRound;
private Command start;
private TextField repeat;
private Form odliczanie;
private Alert ostrz;
Licznik thread;
String test;
StringItem test1;
int parz,i,j,k;
static int l;
int ilrund;
int ilpowt;
Item sec;
long sec1;
public intervals()
    rundy = new Form("Interwały sportowe");
    exitCommand = new Command("Wyjście", Command.EXIT, 2);
    addRound = new Command("Dodaj","Dodaj rundę", Command.ITEM,1);
    delRound = new Command("Usuń","Usuń ostatnią rundę", Command.ITEM,1);
    start = new Command("Start", Command.ITEM,1);
    odliczanie = new Form("Odliczanie");
    TextField dodaj(TextField kolej)
        kolej=new TextField("Podaj czas (s) rundy "+parz,null, 4, TextField.NUMERIC);//stworzenie nowej instancji do wybierania czasu trwania rundy
        if(rundy.size()==0)
            rundy.insert(rundy.size(),kolej);
            else
                rundy.insert(rundy.size()-1, kolej);
        return kolej;
    void odliczanie(TextField round)
        monitor m=new monitor();
        k=Integer.parseInt(round.getString());
        ekran.setCurrent(odliczanie);
        thread=new Licznik(k,odliczanie);
        thread.start();
        ekran.setCurrent(rundy);
public void startApp()// throws MIDletStateChangeException
    rundy.deleteAll();
    repeat = new TextField("Podaj ilość powtórzeń",null,1,TextField.NUMERIC);
    rundy.addCommand(addRound);
    rundy.addCommand(exitCommand);
    rundy.setCommandListener(this);
    Canvas obrazek = new MyCanvas();
    ekran = Display.getDisplay(this);
    ekran.setCurrent(obrazek);
    czas=System.currentTimeMillis();
    while (System.currentTimeMillis()<czas+1000)
        continue;
    ekran.setCurrent(rundy);
public void pauseApp()
public void destroyApp(boolean unconditional)
    notifyDestroyed();
public void commandAction(Command c, Displayable s)
    if (c == exitCommand)
        destroyApp(false);
        notifyDestroyed();
    else if(c==addRound)
        if(rundy.size()==0)//Sprawdzenie ilości elementów w celu poprawnego wyświetlania liczby rund w formie
            parz=1;
            else
            parz=rundy.size();
        switch(parz)
            case 1:
                round0=dodaj(round0);break;
            case 2:
                round1=dodaj(round1);break;
            case 3:
               round2= dodaj(round2);break;
            case 4:
                round3=dodaj(round3);break;
            case 5:
                round4=dodaj(round4);break;
            default:
                ostrz=new Alert("Uwaga","Maksymalna liczba rund wynosi 9", null, AlertType.INFO);
                ostrz.setTimeout(3000);
                ekran.setCurrent(ostrz);
        if(rundy.size()==1)
            rundy.append(repeat);
            rundy.addCommand(start);
        rundy.addCommand(delRound);
    else if(c==delRound)
        if(rundy.size()!=0)
            rundy.delete(rundy.size()-2);
            if (rundy.size()==1)
                rundy.deleteAll();
            if(rundy.size()==0)
                rundy.removeCommand(delRound);
                rundy.removeCommand(start);
    else if(c==start)
        ilrund=rundy.size()-1;
        if(this.repeat.size()>0)
            ilpowt=Integer.parseInt(this.repeat.getString());
        ekran = Display.getDisplay(this);
        for (i=1; i<=ilpowt;i++)
            odliczanie= new Form("Odliczanie");
             for (j=0;j<ilrund;j++)
                switch(j)
                     case 0:
                         odliczanie(round0);
                         break;
                     case 1:
                         odliczanie(round1);
                         break;
                     case 2:
                         odliczanie(round2);
                         break;
                     case 3:
                         odliczanie(round3);
                         break;
                     case 4:
                         odliczanie(round4);
                         break;
                     case 5:
                         odliczanie(round5);
                         break;
                     case 6:
                         odliczanie(round6);
                         break;
                     case 7:
                         odliczanie(round7);
                         break;
                     case 8:
                         odliczanie(round8);
                         break;
class Licznik extends Thread
    int czas1,k;
    Form forma;
    monitor m;
    public Licznik(int k,Form formap)
        czas1=k;
        forma=formap;
    public synchronized void run()
        while(czas1>0)
            forma.deleteAll();
            forma.append("Czas pozostały (s): "+czas1);
            try{Thread.sleep(1000);} catch(InterruptedException e){e.printStackTrace();}
            czas1--;
        if(czas1<=0)
            m.put();
    }and monitor class
public class monitor
boolean busy=false;
synchronized void get()
    if(!busy)
        try
            wait();
        }catch(InterruptedException e){e.printStackTrace();}
    notify();
synchronized void put()
    if(busy)
        try
        wait();
        }catch(InterruptedException e){e.printStackTrace();}
    busy=true;
    notify();
}Can anybody help me with this?

Groovemaker,
Your Licznik class has a member m of type monitor, which has not been instantiated (in other words is null) hence, when calling m.put() you get NullPointerException. Please also mind, that using Thread.sleep(1000) is not an accurate way of measuring time.
If I may, please use recommended for Java class naming conventions - some of your names use lower case, while other don't which is confusing to the reader.
Daniel

Problem with threads within applet

Hello,
I got an applet, inside this applet I have a singleton, inside this singleton I have a thread.
this thread is running in endless loop.
he is doing something and go to sleep on and on.
the problem is,
when I refresh my IE6 browser I see more than 1 thread.
for debug matter, I did the following things:
inside the thread, sysout every time he goes to sleep.
sysout in the singleton constructor.
sysout in the singleton destructor.
the output goes like this:
when refresh the page, the singleton constructor loading but not every refresh, sometimes I see the constructor output and sometimes I dont.
The thread inside the singleton is giving me the same output, sometime I see more than one thread at a time and sometimes I dont.
The destructor never works (no output there).
I don't understand what is going on.
someone can please shed some light?
thanks.
btw. I am working with JRE 1.1
this is very old and big applet and I can't convert it to something new.

Ooops. sorry!
I did.
     public void start() {
     public void stop() {
     public void destroy() {
          try {
               resetAll();
               Configuration.closeConnection();
               QuoteItem.closeConnection();
          } finally {
               try {
                    super.finalize();
               } catch (Throwable e) {
                    e.printStackTrace();
     }

Problem with Threads and a static variable

I have a problem with the code below. I am yet to make sure that I understand the problem. Correct me if I am wrong please.
Code functionality:
A timer calls SetState every second. It sets the state and sets boolean variable "changed" to true. Then notifies a main process thread to check if the state changed to send a message.
The problem as far I understand is:
Assume the timer Thread calls SetState twice before the main process Thread runs. As a result, "changed" is set to true twice. However, since the main process is blocked twice during the two calls to SetState, when it runs it would have the two SetState timer threads blocked on its synchronized body. It will pass the first one, send the message and set "changed" to false since it was true. Now, it will pass the second thread, but here is the problem, "changed" is already set to false. As a result, it won't send the message even though it is supposed to.
Would you please let me know if my understanding is correct? If so, what would you propose to resolve the problem? Should I call wait some other or should I notify in a different way?
Thanks,
B.D.
Code:
private static volatile boolean bChanged = false;
private static Thread objMainProcess;
   protected static void Init(){
        objMainProcess = new Thread() {
            public void run() {
                while( objMainProcess == Thread.currentThread() ) {
                   GetState();
        objMainProcess.setDaemon( true );
        objMainProcess.start();
    public static void initStatusTimer(){
        if(objTimer == null)
             objTimer = new javax.swing.Timer( 1000, new java.awt.event.ActionListener(){
                public void actionPerformed( java.awt.event.ActionEvent evt){
                          SetState();
    private static void SetState(){
        if( objMainProcess == null ) return;
        synchronized( objMainProcess ) {
            bChanged = true;
            try{
                objMainProcess.notify();
            }catch( IllegalMonitorStateException e ) {}
    private static boolean GetState() {
        if( objMainProcess == null ) return false;
        synchronized( objMainProcess ) {
            if( bChanged) {
                SendMessage();
                bChanged = false;
                return true;
            try {
                objMainProcess.wait();
            }catch( InterruptedException e ) {}
            return false;
    }

Thanks DrClap for your reply. Everything you said is right. It is not easy to make them alternate since SetState() could be called from different places where the state could be anything else but a status message. Like a GREETING message for example. It is a handshaking message but not a status message.
Again as you said, There is a reason I can't call sendMessage() inside setState().
The only way I was able to do it is by having a counter of the number of notifies that have been called. Every time notify() is called a counter is incremented. Now instead of just checking if "changed" flag is true, I also check if notify counter is greater than zero. If both true, I send the message. If "changed" flag is false, I check again if the notify counter is greater than zero, I send the message. This way it works, but it is kind of a patch than a good design fix. I am yet to find a good solution.
Thanks,
B.D.

Problem with threads running javaw

Hi,
Having a problem with multi thread programming using client server sockets. The program works find when starting the the application in a console using java muti.java , but when using javaw multi.java the program doesnt die and have to kill it in the task manager. The program doesnt display any of my gui error messages either when the server disconnect the client. all works find in a console. any advice on this as I havent been able to understand why this is happening? any comment would be appreciated.
troy.

troy,
Try and post a minimum code sample of your app which
does not work.
When using javaw, make sure you redirect the standard
error and standard output streams to file.
Graeme.Hi Graeme,
I dont understand what you mean by redirection to file? some of my code below.
The code works fine under a console, code is supposed to exit when the client (the other server )disconnects. the problem is that but the clientworker side of the code still works. which under console it doesnt.
public class Server{
ServerSocket aServerSocket;
Socket dianosticsSocket;
Socket nPortExpress;
ClientListener aClientListener;
LinkedList queue = new LinkedList();
int port = 0;
int clientPort = 0;
String clientName = null;
boolean serverAlive = true;
* Server constructor generates a server
* Socket and then starts a client threads.
* @param aPort      socket port of local machine.
public Server(int aPort, String aClientName, int aClientPort){
port = aPort;
clientName = aClientName;
clientPort = aClientPort;
try{
// create a new thread
aServerSocket = new ServerSocket(port) ;
// connect to the nPortExpress
aClientListener = new ClientListener(InetAddress.getByName(clientName), clientPort, queue,this);
// aClientListener.setDaemon(true);
aClientListener.start();
// start a dianostic port
DiagnosticsServer aDiagnosticsServer = new DiagnosticsServer(port,queue,aClientListener);
// System.out.println("Server is running on port " + port + "...");
// System.out.println("Connect to nPort");
catch(Exception e)
// System.out.println("ERROR: Server port " + port + " not available");
JOptionPane.showMessageDialog(null, (e.toString()),"ERROR: Server port " + port + " not available", JOptionPane.ERROR_MESSAGE);
serverAlive = false;
System.exit(1);
while(serverAlive&&aClientListener.hostSocket.isConnected()){
try{
// connect the client
Socket aClient = aServerSocket.accept();
//System.out.println("open client connection");
//System.out.println("client local: "+ aClient.getLocalAddress().toString());
// System.out.println("client localport: "+ aClient.getLocalPort());
// System.out.println("client : "+ aClient.getInetAddress().toString());
// System.out.println("client port: "+ aClient.getLocalPort());
// make a new client thread
ClientWorker clientThread = new ClientWorker(aClient, queue, aClientListener, false);
// start thread
clientThread.start();
catch(Exception e)
//System.out.println("ERROR: Client connection failure");
JOptionPane.showMessageDialog(null, (e.toString()),"ERROR: Client connection failure", JOptionPane.ERROR_MESSAGE);
}// end while
} // end constructor Server
void serverExit(){
     JOptionPane.showMessageDialog(null, "Server ","ERROR: nPort Failure", JOptionPane.ERROR_MESSAGE);
     System.exit(1);
}// end class Server
*** connect to another server
public class ClientListener extends Thread{
InetAddress hostName;
int hostPort;
Socket hostSocket;
BufferedReader in;
PrintWriter out;
boolean loggedIn;
LinkedList queue;      // reference to Server queue
Server serverRef; // reference to main server
* ClientListener connects to the host server.
* @param aHostName is the name of the host eg server name or IP address.
* @param aHostPort is a port number of the host.
* @param aLoginName is the users login name.
public ClientListener(InetAddress aHostName, int aHostPort,LinkedList aQueue,Server aServer)      // reference to Server queue)
hostName = aHostName;
hostPort = aHostPort;
queue = aQueue;
serverRef = aServer;
// connect to the server
try{
hostSocket = new Socket(hostName, hostPort);
catch(IOException e){
//System.out.println("ERROR: Connection Host Failed");
JOptionPane.showMessageDialog(null, (e.toString()),"ERROR: Connection to nPort Failed", JOptionPane.ERROR_MESSAGE);
System.exit(0);
} // end constructor ClientListener
** multi client connection server
ClientWorker(Socket aSocket,LinkedList aQueue, ClientListener aClientListener, boolean diagnostics){
queue = aQueue;
addToQueue(this);
client = aSocket;
clientRef = aClientListener;
aDiagnostic = diagnostics;
} // end constructor ClientWorker
* run method is the main loop of the server program
* in change of handle new client connection as well
* as handle all messages and errors.
public void run(){
boolean alive = true;
String aSubString = "";
in = null;
out = null;
loginName = "";
loggedIn = false;
while (alive && client.isConnected()&& clientRef.hostSocket.isConnected()){
try{
in = new BufferedReader(new InputStreamReader(client.getInputStream()));
out = new PrintWriter(new OutputStreamWriter(client.getOutputStream()));
if(aDiagnostic){
out.println("WELCOME to diagnostics");
broadCastDia("Connect : diagnostics "+client.getInetAddress().toString());
out.flush();
else {
out.println("WELCOME to Troy's Server");
broadCastDia("Connect : client "+client.getInetAddress().toString());
     out.flush();
String line;
while(((line = in.readLine())!= null)){
StringTokenizer aStringToken = new StringTokenizer(line, " ");
if(!aDiagnostic){
broadCastDia(line);
clientRef.sendMessage(line); // send mesage out to netExpress
out.println(line);
out.flush();
else{
if(line.equals("GETIPS"))
getIPs();
else{
clientRef.sendMessage(line); // send mesage out to netExpress
out.println(line);
out.flush();
} // end while
catch(Exception e){
// System.out.println("ERROR:Client Connection reset");
                         JOptionPane.showMessageDialog(null, (e.toString()),"ERROR:Client Connection reset", JOptionPane.ERROR_MESSAGE);
try{
if(aDiagnostic){
broadCastDia("Disconnect : diagnostics "+client.getInetAddress().toString());
out.flush();
else {
broadCastDia("Disconnect : client "+client.getInetAddress().toString());
     out.flush();
// close the buffers and connection;
in.close();
out.close();
client.close();
// System.out.println("out");
// remove from list
removeThreadQueue(this);
alive = false;
catch(Exception e){
// System.out.println("ERROR: Client Connection reset failure");
JOptionPane.showMessageDialog(null, (e.toString()),"ERROR: Client Connection reset failure", JOptionPane.ERROR_MESSAGE);
}// end while
} // end method run
* method run - Generates io stream for communicating with the server and
* starts the client gui. Run also parses the input commands from the server.
public void run(){
boolean alive = true;
try{
// begin to life the gui
// aGuiClient = new ClientGui(hostName.getHostName(), hostPort, loginName, this);
// aGuiClient.show();
in = new BufferedReader(new InputStreamReader(hostSocket.getInputStream()));
out = new PrintWriter(new OutputStreamWriter(hostSocket.getOutputStream()));
while (alive && hostSocket.isConnected()){
String line;
while(((line = in.readLine())!= null)){
System.out.println(line);
broadCast(line);
} // end while
} // end while
catch(Exception e){
//     System.out.println("ERRORa Connection to host reset");
JOptionPane.showMessageDialog(null, (e.toString()),"ERROR: Connection to nPort reset", JOptionPane.ERROR_MESSAGE);
try{
hostSocket.close();
     }catch(Exception a){
     JOptionPane.showMessageDialog(null, (a.toString()),"ERROR: Exception", JOptionPane.ERROR_MESSAGE);
alive = false;
System.exit(1);
} // end method run

Problem with Threads and "plase wait..."-Window

Hi everyone,
I have a problem that I'm not able to solve in any way... I have a time-consuming task (a file decryption) which I execute in a separate thread; I've used the SwingWorker class, like suggested by sun-tutorial, and it works right. The problem is that I have to wait that the decryption have finished before continuing with program-execution. Therefore I would like to display a "please wait"-window while the task runs. I've tryed all the possible ways I know but the problem is always the same: the waitWindow is displayed empty, the bounds are painted but the contents no; it's only painted when the decrypt-task has finished. Please help me, I have no more resources....
decrypt-file code:
public class DecryptFile {
private String cryptedFileNameAndPath;
private ByteArrayInputStream resultStream = null;
// need for progress
private int lengthOfTask;
private int current = -1;
private String statMessage;
public DecryptFile(String encZipFileNameAndPath) {
    cryptedFileNameAndPath = encZipFileNameAndPath;
    //Compute length of task...
    // 0 for indeterminate
    lengthOfTask = 0;
public ByteArrayInputStream getDecryptedInputStream() {
    return this.resultStream;
   * Called from ProgressBarDemo to start the task.
public void go() {
    current = -1;
    final SwingWorker worker = new SwingWorker() {
      public Object construct() {
        return new ActualTask();
    worker.start();
   * Called from ProgressBarDemo to find out how much work needs
   * to be done.
public int getLengthOfTask() {
    return lengthOfTask;
   * Called from ProgressBarDemo to find out how much has been done.
public int getCurrent() {
    return current;
public void stop() {
    current = lengthOfTask;
   * Called from ProgressBarDemo to find out if the task has completed.
public boolean done() {
    if (current >= lengthOfTask)
      return true;
    else
      return false;
public String getMessage() {
    return statMessage;
   * The actual long running task. This runs in a SwingWorker thread.
class ActualTask {
    ActualTask () {
      current = -1;
      statMessage = "";
      resultStream = AIUtil.getInputStreamFromEncZip(cryptedFileNameAndPath); //here the decryption happens
      current = 0;
      statMessage = "";
}The code that calls decryption and displays waitWindow
      final WaitSplash wS = new WaitSplash("Please wait...");
      final DecryptFile cryptedTemplate = new DecryptFile (this.templateFile);
      cryptedTemplate.go();
      while (! cryptedTemplate.done()) {
        try {
          wait();
        } catch (Exception e) { }
      this.templateInputStream = cryptedTemplate.getDecryptedInputStream();
      wS.close();Thanks, thanks, thanks in advance!
Edoardo

Maybe you can try setting the priority of the long-running thread to be lower? so that the UI will be more responsive...

ClientAbortException Problem

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