Eclipse cannot start Debug As

I am working on Java project in Eclipse. I can start application (Run As ) and i works fine, but I cannot start Debug As ( I could start Debug As but suddenly I cannot anymore ). Does anybody have experience with this weird stuff ?

@dimitrisil in debug console

MainWindow (1) [Java Application]   
    com.euroicc.histo.view.MainWindow at localhost:4325 
        Thread [AWT-Shutdown] (Running) 
        Daemon Thread [AWT-Windows] (Running)   
        Thread [AWT-EventQueue-0] (Suspended (exception NumberFormatException)) 
            Integer.parseInt(String, int) line: not available   
            Integer.<init>(String) line: not available  
            InetAddressCachePolicy.<clinit>() line: not available   
            InetAddress$Cache.getPolicy() line: not available   
            InetAddress$Cache.put(String, Object) line: not available   
            InetAddress.cacheInitIfNeeded() line: not available 
            InetAddress.cacheAddress(String, Object, boolean) line: not available   
            InetAddress.getAddressFromNameService(String, InetAddress) line: not available  
            InetAddress.getLocalHost() line: not available  
            SeedGenerator$1.run() line: not available   
            AccessController.doPrivileged(PrivilegedAction<T>) line: not available [native method]  
            SeedGenerator.getSystemEntropy() line: not available    
            SecureRandom.engineNextBytes(byte[]) line: not available    
            SecureRandom.nextBytes(byte[]) line: not available  
            SecureRandom.next(int) line: not available  
            SecureRandom(Random).nextLong() line: not available 
            File.generateFile(String, String, File) line: not available 
            File.createTempFile(String, String, File) line: not available   
            FileCacheImageInputStream.<init>(InputStream, File) line: not available 
            InputStreamImageInputStreamSpi.createInputStreamInstance(Object, boolean, File) line: not available 
            ImageIO.createImageInputStream(Object) line: not available  
            ImageIO.read(URL) line: not available   
            BrushedMetalDecorationPainter.<init>() line: 69 
            BusinessBlackSteelSkin.<init>() line: 135   
            SubstanceBusinessBlackSteelLookAndFeel.<init>() line: 54    
            MainWindow$7.run() line: 238    
            InvocationEvent.dispatch() line: not available  
            EventQueue.dispatchEvent(AWTEvent) line: not available  
            EventDispatchThread.pumpOneEventForFilters(int) line: not available 
            EventDispatchThread.pumpEventsForFilter(int, Conditional, EventFilter) line: not available  
            EventDispatchThread.pumpEventsForHierarchy(int, Conditional, Component) line: not available 
            EventDispatchThread.pumpEvents(int, Conditional) line: not available    
            EventDispatchThread.pumpEvents(Conditional) line: not available 
            EventDispatchThread.run() line: not available   
        Thread [DestroyJavaVM] (Running)    
    C:\Program Files\Java\jre1.6.0_17\bin\javaw.exe (17.12.2010. 15.00.45)  
MainWindow (1) [Java Application]   
    com.euroicc.histo.view.MainWindow at localhost:4363 
        Thread [AWT-Shutdown] (Running) 
        Daemon Thread [AWT-Windows] (Running)   
        Thread [AWT-EventQueue-0] (Suspended (exception NumberFormatException)) 
            Integer.parseInt(String, int) line: not available   
            Integer.<init>(String) line: not available  
            InetAddressCachePolicy.<clinit>() line: not available   
            InetAddress$Cache.getPolicy() line: not available   
            InetAddress$Cache.put(String, Object) line: not available   
            InetAddress.cacheInitIfNeeded() line: not available 
            InetAddress.cacheAddress(String, Object, boolean) line: not available   
            InetAddress.getAddressFromNameService(String, InetAddress) line: not available  
            InetAddress.getLocalHost() line: not available  
            SeedGenerator$1.run() line: not available   
            AccessController.doPrivileged(PrivilegedAction<T>) line: not available [native method]  
            SeedGenerator.getSystemEntropy() line: not available    
            SecureRandom.engineNextBytes(byte[]) line: not available    
            SecureRandom.nextBytes(byte[]) line: not available  
            SecureRandom.next(int) line: not available  
            SecureRandom(Random).nextLong() line: not available 
            File.generateFile(String, String, File) line: not available 
            File.createTempFile(String, String, File) line: not available   
            FileCacheImageInputStream.<init>(InputStream, File) line: not available 
            InputStreamImageInputStreamSpi.createInputStreamInstance(Object, boolean, File) line: not available 
            ImageIO.createImageInputStream(Object) line: not available  
            ImageIO.read(URL) line: not available   
            BrushedMetalDecorationPainter.<init>() line: 69 
            BusinessBlackSteelSkin.<init>() line: 135   
            SubstanceBusinessBlackSteelLookAndFeel.<init>() line: 54    
            MainWindow$7.run() line: 238    
            InvocationEvent.dispatch() line: not available  
            EventQueue.dispatchEvent(AWTEvent) line: not available  
            EventDispatchThread.pumpOneEventForFilters(int) line: not available 
            EventDispatchThread.pumpEventsForFilter(int, Conditional, EventFilter) line: not available  
            EventDispatchThread.pumpEventsForHierarchy(int, Conditional, Component) line: not available 
            EventDispatchThread.pumpEvents(int, Conditional) line: not available    
            EventDispatchThread.pumpEvents(Conditional) line: not available 
            EventDispatchThread.run() line: not available   
        Thread [DestroyJavaVM] (Running)    
    C:\Program Files\Java\jre1.6.0_17\bin\javaw.exe (17.12.2010. 15.01.06)  
MainWindow (1) [Java Application]   
    com.euroicc.histo.view.MainWindow at localhost:4369 
        Thread [AWT-Shutdown] (Running) 
        Daemon Thread [AWT-Windows] (Running)   
        Thread [AWT-EventQueue-0] (Suspended (exception NumberFormatException)) 
            Integer.parseInt(String, int) line: not available   
            Integer.<init>(String) line: not available  
            InetAddressCachePolicy.<clinit>() line: not available   
            InetAddress$Cache.getPolicy() line: not available   
            InetAddress$Cache.put(String, Object) line: not available   
            InetAddress.cacheInitIfNeeded() line: not available 
            InetAddress.cacheAddress(String, Object, boolean) line: not available   
            InetAddress.getAddressFromNameService(String, InetAddress) line: not available  
            InetAddress.getLocalHost() line: not available  
            SeedGenerator$1.run() line: not available   
            AccessController.doPrivileged(PrivilegedAction<T>) line: not available [native method]  
            SeedGenerator.getSystemEntropy() line: not available    
            SecureRandom.engineNextBytes(byte[]) line: not available    
            SecureRandom.nextBytes(byte[]) line: not available  
            SecureRandom.next(int) line: not available  
            SecureRandom(Random).nextLong() line: not available 
            File.generateFile(String, String, File) line: not available 
            File.createTempFile(String, String, File) line: not available   
            FileCacheImageInputStream.<init>(InputStream, File) line: not available 
            InputStreamImageInputStreamSpi.createInputStreamInstance(Object, boolean, File) line: not available 
            ImageIO.createImageInputStream(Object) line: not available  
            ImageIO.read(URL) line: not available   
            BrushedMetalDecorationPainter.<init>() line: 69 
            BusinessBlackSteelSkin.<init>() line: 135   
            SubstanceBusinessBlackSteelLookAndFeel.<init>() line: 54    
            MainWindow$7.run() line: 238    
            InvocationEvent.dispatch() line: not available  
            EventQueue.dispatchEvent(AWTEvent) line: not available  
            EventDispatchThread.pumpOneEventForFilters(int) line: not available 
            EventDispatchThread.pumpEventsForFilter(int, Conditional, EventFilter) line: not available  
            EventDispatchThread.pumpEventsForHier开发者_如何学JAVAarchy(int, Conditional, Component) line: not available 
            EventDispatchThread.pumpEvents(int, Conditional) line: not available    
            EventDispatchThread.pumpEvents(Conditional) line: not available 
            EventDispatchThread.run() line: not available   
        Thread [DestroyJavaVM] (Running)    
    C:\Program Files\Java\jre1.6.0_17\bin\javaw.exe (17.12.2010. 15.01.30)  
MainWindow (1) [Java Application]   
    com.euroicc.histo.view.MainWindow at localhost:4383 
        Thread [AWT-Shutdown] (Running) 
        Daemon Thread [AWT-Windows] (Running)   
        Thread [AWT-EventQueue-0] (Suspended (exception NumberFormatException)) 
            Integer.parseInt(String, int) line: not available   
            Integer.<init>(String) line: not available  
            InetAddressCachePolicy.<clinit>() line: not available   
            InetAddress$Cache.getPolicy() line: not available   
            InetAddress$Cache.put(String, Object) line: not available   
            InetAddress.cacheInitIfNeeded() line: not available 
            InetAddress.cacheAddress(String, Object, boolean) line: not available   
            InetAddress.getAddressFromNameService(String, InetAddress) line: not available  
            InetAddress.getLocalHost() line: not available  
            SeedGenerator$1.run() line: not available   
            AccessController.doPrivileged(PrivilegedAction<T>) line: not available [native method]  
            SeedGenerator.getSystemEntropy() line: not available    
            SecureRandom.engineNextBytes(byte[]) line: not available    
            SecureRandom.nextBytes(byte[]) line: not available  
            SecureRandom.next(int) line: not available  
            SecureRandom(Random).nextLong() line: not available 
            File.generateFile(String, String, File) line: not available 
            File.createTempFile(String, String, File) line: not available   
            FileCacheImageInputStream.<init>(InputStream, File) line: not available 
            InputStreamImageInputStreamSpi.createInputStreamInstance(Object, boolean, File) line: not available 
            ImageIO.createImageInputStream(Object) line: not available  
            ImageIO.read(URL) line: not available   
            BrushedMetalDecorationPainter.<init>() line: 69 
            BusinessBlackSteelSkin.<init>() line: 135   
            SubstanceBusinessBlackSteelLookAndFeel.<init>() line: 54    
            MainWindow$7.run() line: 238    
            InvocationEvent.dispatch() line: not available  
            EventQueue.dispatchEvent(AWTEvent) line: not available  
            EventDispatchThread.pumpOneEventForFilters(int) line: not available 
            EventDispatchThread.pumpEventsForFilter(int, Conditional, EventFilter) line: not available  
            EventDispatchThread.pumpEventsForHierarchy(int, Conditional, Component) line: not available 
            EventDispatchThread.pumpEvents(int, Conditional) line: not available    
            EventDispatchThread.pumpEvents(Conditional) line: not available 
            EventDispatchThread.run() line: not available   
        Thread [DestroyJavaVM] (Running)    
    C:\Program Files\Java\jre1.6.0_17\bin\javaw.exe (17.12.2010. 15.05.23)  
MainWindow (1) [Java Application]   
    com.euroicc.histo.view.MainWindow at localhost:2740 
        Thread [AWT-Shutdown] (Running) 
        Daemon Thread [AWT-Windows] (Running)   
        Thread [AWT-EventQueue-0] (Suspended (exception NumberFormatException)) 
            Integer.parseInt(String, int) line: not available   
            Integer.<init>(String) line: not available  
            InetAddressCachePolicy.<clinit>() line: not available   
            InetAddress$Cache.getPolicy() line: not available   
            InetAddress$Cache.put(String, Object) line: not available   
            InetAddress.cacheInitIfNeeded() line: not available 
            InetAddress.cacheAddress(String, Object, boolean) line: not available   
            InetAddress.getAddressFromNameService(String, InetAddress) line: not available  
            InetAddress.getLocalHost() line: not available  
            SeedGenerator$1.run() line: not available   
            AccessController.doPrivileged(PrivilegedAction<T>) line: not available [native method]  
            SeedGenerator.getSystemEntropy() line: not available    
            SecureRandom.engineNextBytes(byte[]) line: not available    
            SecureRandom.nextBytes(byte[]) line: not available  
            SecureRandom.next(int) line: not available  
            SecureRandom(Random).nextLong() line: not available 
            File.generateFile(String, String, File) line: not available 
            File.createTempFile(String, String, File) line: not available   
            FileCacheImageInputStream.<init>(InputStream, File) line: not available 
            InputStreamImageInputStreamSpi.createInputStreamInstance(Object, boolean, File) line: not available 
            ImageIO.createImageInputStream(Object) line: not available  
            ImageIO.read(URL) line: not available   
            BrushedMetalDecorationPainter.<init>() line: 69 
            BusinessBlackSteelSkin.<init>() line: 135   
            SubstanceBusinessBlackSteelLookAndFeel.<init>() line: 54    
            MainWindow$7.run() line: 238    
            InvocationEvent.dispatch() line: not available  
            EventQueue.dispatchEvent(AWTEvent) line: not available  
            EventDispatchThread.pumpOneEventForFilters(int) line: not available 
            EventDispatchThread.pumpEventsForFilter(int, Conditional, EventFilter) line: not available  
            EventDispatchThread.pumpEventsForHierarchy(int, Conditional, Component) line: not available 
            EventDispatchThread.pumpEvents(int, Conditional) line: not available    
            EventDispatchThread.pumpEvents(Conditional) line: not available 
            EventDispatchThread.run() line: not available   
        Thread [DestroyJavaVM] (Running)    
    C:\Program Files\Java\jre1.6.0_17\bin\javaw.exe (17.12.2010. 16.17.11)  
MainWindow (1) [Java Application]   
    com.euroicc.histo.view.MainWindow at localhost:2926 
        Thread [AWT-Shutdown] (Running) 
        Daemon Thread [AWT-Windows] (Running)   
        Thread [DestroyJavaVM] (Running)    
        Thread [AWT-EventQueue-0] (Suspended (exception NumberFormatException)) 
            Integer.parseInt(String, int) line: not available   
            Integer.<init>(String) line: not available  
            InetAddressCachePolicy.<clinit>() line: not available   
            InetAddress$Cache.getPolicy() line: not available   
            InetAddress$Cache.put(String, Object) line: not available   
            InetAddress.cacheInitIfNeeded() line: not available 
            InetAddress.cacheAddress(String, Object, boolean) line: not available   
            InetAddress.getAddressFromNameService(String, InetAddress) line: not available  
            InetAddress.getLocalHost() line: not available  
            SeedGenerator$1.run() line: not available   
            AccessController.doPrivileged(PrivilegedAction<T>) line: not available [native method]  
            SeedGenerator.getSystemEntropy() line: not available    
            SecureRandom.engineNextBytes(byte[]) line: not available    
            SecureRandom.nextBytes(byte[]) line: not available  
            SecureRandom.next(int) line: not available  
            SecureRandom(Random).nextLong() line: not available 
            File.generateFile(String, String, File) line: not available 
            File.createTempFile(String, String, File) line: not available   
            FileCacheImageInputStream.<init>(InputStream, File) line: not available 
            InputStreamImageInputStreamSpi.createInputStreamInstance(Object, boolean, File) line: not available 
            ImageIO.createImageInputStream(Object) line: not available  
            ImageIO.read(URL) line: not available   
            BrushedMetalDecorationPainter.<init>() line: 69 
            BusinessBlackSteelSkin.<init>() line: 135   
            SubstanceBusinessBlackSteelLookAndFeel.<init>() line: 54    
            MainWindow$7.run() line: 238    
            InvocationEvent.dispatch() line: not available  
            EventQueue.dispatchEvent(AWTEvent) line: not available  
            EventDispatchThread.pumpOneEventForFilters(int) line: not available 
            EventDispatchThread.pumpEventsForFilter(int, Conditional, EventFilter) line: not available  
            EventDispatchThread.pumpEventsForHierarchy(int, Conditional, Component) line: not available 
            EventDispatchThread.pumpEvents(int, Conditional) line: not available    
            EventDispatchThread.pumpEvents(Conditional) line: not available 
            EventDispatchThread.run() line: not available   
    C:\Program Files\Java\jre1.6.0_17\bin\javaw.exe (17.12.2010. 16.37.37)  

I have seen those two menus become separately confused about their target. For example, for an Ant buildfile, one will continue to be titled "Run As>Ant Build" and the other will be titled something else, and fail.

Restarting Eclipse has always solved the problem.

Based on the (poorly formatted) answer that really ought to be part of the question, it looks like you might have a malformed socket address.

The NumberFormatException is repeated over and over again, in regards to INetAddress.getLocalhost...

Ah! Do you have IPv4 or IPv6? If a v4 (decimal) interpreter tried to parse a v6 (hex) address, things could get mangled.

It could also be that your debug socket number isn't a number (at least not a decimal one)... but I don't see anywhere in the UI to adjust this so I don't see how you could have broken it.

Just for the case someone will get to the same problem in future. Recently I was fooled by the same use-case (however in NetBeans) - the problem was caused by the breakpoint on java.lang.IllegalArgumentException I've created some time ago and forgot about it, so IDE was stopping all the time somewhere in the Java core code just because of that breakpoint, but I was thinking it was caused by something in my code or run-time environment :(

Actually, I would say that this problem is in general coding style in core Java libraries. There are to many places where exceptions are thrown in the cases where if() condition would be more appropriate and this causes major problem in debugging of Exceptions - there are just too many of them. In that particular case problem it is caused by the following lines (I took sources of InetAddressCachePolicy from here http://download.java.net/openjdk/jdk6/):

    try {
        tmp = new Integer(
          java.security.AccessController.doPrivileged (
            new PrivilegedAction<String>() {
              public String run() {
                  return Security.getProperty(cachePolicyProp);
              }
          }));
    } catch (NumberFormatException e) {
        // ignore
    }

You may notice that someone who wrote the code was aware about potential 'not-a-number' String provided in configuration, but did not try to handle more elegantly at least cases of String is null or empty, which is actually the case for that problem.

There is relevant discussion about Integer.parseInt() here - Java: Good way to encapsulate Integer.parseInt()