Question

I have a Swing application, and even though I have everything in a try/block, the exception isn’t caught.

public static void main(String[] args) {      try {         App app = new App();         app.setVisible(true);      } catch (Throwable e) {        System.err.println('never printed');     } } 

all I get is this stack trace:

Exception in thread 'AWT-EventQueue-0'  java.lang.ArrayIndexOutOfBoundsException:  9 >= 9 at java.util.Vector.elementAt(Vector.java:427) at javax.swing.table.DefaultTableModel.getValueAt(DefaultTableModel.java:633) at javax.swing.JTable.getValueAt(JTable.java:2695) at javax.swing.JTable.prepareRenderer(JTable.java:5712) at javax.swing.plaf.basic.BasicTableUI.paintCell(BasicTableUI.java:2075) at javax.swing.plaf.basic.BasicTableUI.paintCells(BasicTableUI.java:1977) at javax.swing.plaf.basic.BasicTableUI.paint(BasicTableUI.java:1773) at javax.swing.plaf.ComponentUI.update(ComponentUI.java:143) at javax.swing.JComponent.paintComponent(JComponent.java:763) at javax.swing.JComponent.paint(JComponent.java:1027) at javax.swing.JComponent.paintChildren(JComponent.java:864) at javax.swing.JComponent.paint(JComponent.java:1036) at javax.swing.JViewport.paint(JViewport.java:747) at javax.swing.JComponent.paintChildren(JComponent.java:864) at javax.swing.JComponent.paint(JComponent.java:1036) at javax.swing.JComponent.paintChildren(JComponent.java:864) at javax.swing.JComponent.paint(JComponent.java:1036) at javax.swing.JComponent.paintChildren(JComponent.java:864) at javax.swing.JComponent.paint(JComponent.java:1036) at javax.swing.JLayeredPane.paint(JLayeredPane.java:564) at javax.swing.JComponent.paintChildren(JComponent.java:864) at javax.swing.JComponent.paintToOffscreen(JComponent.java:5129) at javax.swing.BufferStrategyPaintManager.paint (BufferStrategyPaintManager.java:277) at javax.swing.RepaintManager.paint(RepaintManager.java:1217) at javax.swing.JComponent.paint(JComponent.java:1013) at java.awt.GraphicsCallback$PaintCallback.run(GraphicsCallback.java:21) at sun.awt.SunGraphicsCallback.runOneComponent(SunGraphicsCallback.java:60) at sun.awt.SunGraphicsCallback.runComponents(SunGraphicsCallback.java:97) at java.awt.Container.paint(Container.java:1780) at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:814) at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:714) at javax.swing.RepaintManager.seqPaintDirtyRegions(RepaintManager.java:694) at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run (SystemEventQueueUtilities.java:128) at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209) at java.awt.EventQueue.dispatchEvent(EventQueue.java:597) at java.awt.EventDispatchThread.pumpOneEventForFilters (EventDispatchThread.java:269) at java.awt.EventDispatchThread.pumpEventsForFilter (EventDispatchThread.java:184) at java.awt.EventDispatchThread.pumpEventsForHierarchy (EventDispatchThread.java:174) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161) at java.awt.EventDispatchThread.run(EventDispatchThread.java:122) 

Answer 1

As mentioned by another poster, your problem is that the exception is being thrown in another thread, the event dispatch thread. A couple of solutions:

• put a try/catch around the actual code where the exception is occurring: e.g. if it’s in response to a button click handled by an ActionListener, put the try/catch inside your actionPerformed() method;
• or, leave the exception as an uncaught exception, and add an uncaught exception handler. For example:

     Thread.setDefaultUncaughtExceptionHandler(new Thread.UncaughtExceptionHandler() {       public void uncaughtException(Thread t, Throwable e) {         // ... do something with exception here ...       }     }); 

On a side-note, you should in principle but your UI startup code in a SwingUtilities.invokeLater().