Maintaining logs of a chat session

[vrk]

Hi All!

I have a chat application to simply send the instant messages, which is working fine. And now i want to maintain a log using this apps.
this apps is developed in java swing.
I am unable to append the chat messages to a logger class in order to maintain the log tht should be in XML format.

Plsss suggest me...how to proceed..

Thanks in Advance!
Vrk.

[zweibieren]

I've written a logger in my application. Perhaps its code can help.
Messages are sent to the log with calls like

Util.log.severe("A terrible thing has happened");

Variable log and class TagLogger are declared in Util.java.
The default logger simply writes the log message to the console.

	static public class TagLogger extends Logger {
		public TagLogger () {
			super("com.physpics", null);
		}
		// interim logger until frame is created
		@Override
		public void log(Level level, String msg)
			{ writeMesssageToConsole(level, msg); }
	}

Also in Utils.java is static code to create an instance of TagLogger
and assign it to a global variable.

	static public TagLogger log;
	public static void setLog(TagLogger newLog) {
		log = newLog; 
	}
	static {   // establish an initial TagLogger; it writes to the console
		setLog(new TagLogger());
	}

The main class of the application creates and installs a new TagLogger.
It writes the message to both the console and a message area in the application:

		// create a logger that also sends the message to the messages panel
		Util.setLog(new Util.TagLogger() {
			@Override
			public void log(Level level, String msg) {
				// show message in application message area
				frame.exposeError(msg, level);
				// show message on console
				Util.writeMesssageToConsole(level, msg, Tagger.this);
			}
		});

The writeMessageToConsole method is declared in Util.java thus:

	/**
	 * Extracts the last element of a fully dotted class name.
	 * @param dotted A dotted class name.
	 * @return the last segment of the name
	 */
	static String classSimpleName(String dotted) {
		int dotx = dotted.lastIndexOf('.');
		if (dotx < 0) return dotted;
		return dotted.substring(dotx+1);
	}

	public static void writeMesssageToConsole(Level level, String msg) {
		String msgInfo = "";
		StackTraceElement[] elements = new Exception().getStackTrace();
		msgInfo = elements[2].getMethodName();
		msgInfo += " from "
				+ classSimpleName(elements[3].getClassName())
				+ "." + elements[3].getMethodName() + "()";
		if (level.intValue() >= Level.WARNING.intValue())
			System.err.println("*** " + msgInfo + "\n" + "      " + msg);
		else
			System.out.println(msgInfo + "\n" + "      " + msg);
	}

Creating XML is a bit of an additional challenge. One tutorial is at:
Chapter*3.*Writing XML with Java