In this example we shall show you how to use a logger’s ConsoleHandler. The ConsoleHandler is a handler that takes logs from a Logger and publishes them to System.err. To use the ConsoleHandler one should perform the following steps:
- Create a Logger instance, with the
getLogger(String name)API method of the Logger. - Create a ConsoleHandler for
System.err. - Add the handler to the logger so as to receive messages from the logger, with the
addHandler(Handler handler)API method. - Check if the logger is enabled to a specific level and then log a message to that level, with the
isLoggable(Level level)andinfo(String msg)API methods,
as described in the code snippet below.
package com.javacodegeeks.snippets.core;
import java.util.logging.Logger;
import java.util.logging.ConsoleHandler;
import java.util.logging.Level;
public class LogConsoleHandler {
public static void main(String[] args) {
// Create Logger instance
Logger logger = Logger.getLogger(LogConsoleHandler.class.getName());
// Add ConsoleHandler
ConsoleHandler consoleHandler = new ConsoleHandler();
logger.addHandler(consoleHandler);
if (logger.isLoggable(Level.INFO)) {
logger.info("This is information message");
}
}
}
Output:
Αυγ 12, 2012 1:06:36 ΜΜ com.javacodegeeks.snippets.core.LogConsoleHandler main
INFO: This is information message
Αυγ 12, 2012 1:06:36 ΜΜ com.javacodegeeks.snippets.core.LogConsoleHandler main
INFO: This is information message
This was an example of how to use logger ConsoleHandler in Java.
why the log message is printed twice ?