DefaultErrorCatcher.java

package com.limegroup.gnutella.gui;

import java.awt.IllegalComponentStateException;
import java.io.PrintWriter;
import java.io.StringWriter;

import com.limegroup.gnutella.ErrorService;

/**
 * @author jum
 *
 * Implement a generic error handler that catches all errors thrown
 * by ActionListeners in the AWT event dispatcher thread.
 */
public class DefaultErrorCatcher {

	static void install() {
	    System.setProperty("sun.awt.exception.handler",
	                       DefaultErrorCatcher.class.getName());
    }
	
	public void handle(Throwable ex) {
	    StringWriter sw = new StringWriter();
	    PrintWriter pw = new PrintWriter(sw);
	    ex.printStackTrace(pw);
	    pw.flush();
	    String bug = sw.toString();
	    
	    if(!isIgnorable(ex, bug))
		    ErrorService.error(ex, "Uncaught event-thread error.");
		else {
		    System.err.println("Ignoring error:");
		    ex.printStackTrace();
        }
	}
	
	/**
	 * Determines if the message can be ignored.
	 */
	private boolean isIgnorable(Throwable bug, String msg) {
	    // ignore all overflows & out of memory errors,
	    // since they'll give us absolutely no debugging information
	    if(bug instanceof StackOverflowError)
	        return true;
	    if(bug instanceof OutOfMemoryError)
	        return true;
	        
        // no bug?  kinda impossible, but shouldn't report.
	    if(msg == null)
	        return true;
	        
        // frickin' repaint manager stinks.
        if(msg.indexOf("javax.swing.RepaintManager") != -1)
            return true;
        if(msg.indexOf("sun.awt.RepaintArea.paint") != -1)
            return true;
         
        // display manager on OSX goes out of whack   
        if(bug instanceof ArrayIndexOutOfBoundsException) {
            if(msg.indexOf("apple.awt.CWindow.displayChanged") != -1)
                return true;
            if(msg.indexOf("javax.swing.plaf.basic.BasicTabbedPaneUI.getTabBounds") != -1)
                return true;
        }
        
        // system clipboard can be held, preventing us from getting.
        // throws a RuntimeException through stuff we don't control...
        if(bug instanceof IllegalStateException) {
            if(msg.indexOf("cannot open system clipboard") != -1)
                return true;
        }
        
        // odd component exception
        if(bug instanceof IllegalComponentStateException) {
            if(msg.indexOf("component must be showing on the screen to determine its location") != -1)
                return true;
        }
	        
        // various NPEs we can ignore:
        if(bug instanceof NullPointerException) {
            if(msg.indexOf("MetalFileChooserUI") != -1)
                return true;
            if(msg.indexOf("WindowsFileChooserUI") != -1)
                return true;
            if(msg.indexOf("AquaDirectoryModel") != -1)
                return true;
            if(msg.indexOf("SizeRequirements.calculateAlignedPositions") != -1)
                return true;
            if(msg.indexOf("BasicTextUI.damageRange") != -1)
                return true;
            if(msg.indexOf("null pData") != -1)
                return true;
             if(msg.indexOf("disposed component") != -1)
                return true;
        }
        
        // various InternalErrors we can ignore.
        if(bug instanceof InternalError) {
            if(msg.indexOf("getGraphics not implemented for this component") != -1)
                return true;
        }
	    
	    // if we're not somewhere in the bug, ignore it.
	    // no need for us to debug sun's internal errors.
	    if(msg.indexOf("com.limegroup.gnutella") == -1)
	        return true;
	        
        // we intercept calls in various places -- check if the only
        // com.limegroup.gnutella is from an intecepted call.
        if(intercepts(msg, "com.limegroup.gnutella.tables.MouseEventConsumptionChecker"))
            return true;
        if(intercepts(msg, "com.limegroup.gnutella.gui.tables.LimeJTable.processMouseEvent"))
            return true;
	        
        return false;
    }
    
    /**
     * Determines if the given string is the only place where 'com.limegroup.gnutella' exists.
     */
    private boolean intercepts(String msg, String inter) {
        int i = msg.indexOf(inter);
        // not intercepted at all?
        if(i == -1)
            return false;
            
        // something before it?
        if(msg.lastIndexOf("com.limegroup.gnutella", i) != -1)
            return false;
            
        i += inter.length();
        if(i >= msg.length())
            return false;
            
        // something after it?
        if(msg.indexOf("com.limegroup.gnutella", i) != -1)
            return false;
            
        // yup, it's the only com.limegroup.gnutella in there.
        return true;
    }   
}