java.util.logging: how to suppress date line

Question

I'm trying to suppress output of the date line durinng logging when using the default logger in java.util.logging. For example, here is a typical output:

Jun 1, 2010 10:18:12 AM gamma.utility.application info

INFO: ping: db-time=2010-06-01 10:18:12.0, local-time=20100601t101812, duration=180000

Jun 1, 2010 10:21:12 AM gamma.utility.application info

INFO: ping: db-time=2010-06-01 10:21:12.0, local-time=20100601t102112, duration=180000

I would like to get rid of the Jun 1, 2010... lines, they just clutter my log output. How can I do this?

Answer 1

Here is an article on how to implement a custom formatter

Answer 2

Write a custom formatter extending java.util.logging.Formatter class and implement the String format(LogRecord) method according to your needs. For example, the following formatter shows only the log message (and the throwable stacktrace if an exception is being logged):

import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.logging.Formatter;
import java.util.logging.LogRecord;

class CustomRecordFormatter extends Formatter {
    @Override
    public String format(final LogRecord r) {
        StringBuilder sb = new StringBuilder();
        sb.append(formatMessage(r)).append(System.getProperty("line.separator"));
        if (null != r.getThrown()) {
            sb.append("Throwable occurred: "); //$NON-NLS-1$
            Throwable t = r.getThrown();
            PrintWriter pw = null;
            try {
                StringWriter sw = new StringWriter();
                pw = new PrintWriter(sw);
                t.printStackTrace(pw);
                sb.append(sw.toString());
            } finally {
                if (pw != null) {
                    try {
                        pw.close();
                    } catch (Exception e) {
                        // ignore
                    }
                }
            }
        }
        return sb.toString();
    }
}

This is how you use it:

import java.util.logging.ConsoleHandler;
import java.util.logging.Logger;

class A {
    private static final Logger LOGGER = Logger.getLogger(A.class.getName());

    static {
        CustomRecordFormatter formatter = new CustomRecordFormatter();
        ConsoleHandler consoleHandler = new ConsoleHandler();
        consoleHandler.setFormatter(formatter);
        LOGGER.addHandler(consoleHandler);
    }

    public void doSomething() {
        LOGGER.info("something happened");
    }
}

Answer 3

The problem is caused by a handler in the parent log. The solution is to remove all handlers from the parent log, and then add own custom handler. This code removes handlers from the parent log:

      for(Handler iHandler:log.getParent().getHandlers())
        {
        log.getParent().removeHandler(iHandler);
        }