view java/src/uk/ac/qmul/eecs/ccmi/utils/CCmIUncaughtExceptionHandler.java @ 0:9418ab7b7f3f

Initial import

/*  
 CCmI Editor - A Collaborative Cross-Modal Diagram Editing Tool
  
 Copyright (C) 2011  Queen Mary University of London (http://ccmi.eecs.qmul.ac.uk/)

 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/  

package uk.ac.qmul.eecs.ccmi.utils;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;
import java.lang.Thread.UncaughtExceptionHandler;
import java.util.logging.FileHandler;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * The UncaughtExceptionHandler for the CCmI Editor. It logs the occurred exception stack trace 
 * on a file (errorN.log, where N is an integer number automatically assigned to avoid
 * collision with other files of the same type) which is created in the same directory where
 * the program is run. The exception stack trace will be in the format defined by the {@code XMLFormatter} class
 * of the java.utli.logging package.
 * 
 * @see java.util.logging.XMLFormatter
 */
public class CCmIUncaughtExceptionHandler implements UncaughtExceptionHandler {
	
	@Override
	public void uncaughtException(Thread thread, Throwable throwable) {
		try{
			Logger logger = Logger.getLogger("uncaught_exception");
			logger.setLevel(Level.SEVERE);
			FileHandler fileHandler = null;
			try {
				fileHandler = new FileHandler("error%u.log",true); 
			} catch (IOException e) {
				System.err.println(throwable.toString());
				System.err.println();
				System.err.println("Could not use error log file");
				e.printStackTrace();
				return;
			}
			fileHandler.setLevel(Level.SEVERE);
			logger.addHandler(fileHandler);
			StringBuilder builder = new StringBuilder(throwable.toString());
			builder.append('\n');
			final Writer result = new StringWriter();
		    final PrintWriter printWriter = new PrintWriter(result);
		    throwable.printStackTrace(printWriter);
		    builder.append(result.toString());
			logger.severe(builder.toString());
			fileHandler.close();
			throwable.printStackTrace();
		}catch(Exception exception){
			exception.printStackTrace();
			System.exit(-1);
		}
	}
}