Package nl.nikhef.jgridstart.logging

Class LogWindowHandler

java.lang.Object

java.util.logging.Handler

nl.nikhef.jgridstart.logging.LogWindowHandler

public class LogWindowHandler
extends Handler

Logging handler that outputs messages to a window

From the book "Logging in Java with the JDK 1.4 Logging API and Apache log4j"

This is a Custom Handler object which publishes its logging information to a separate Java window. This follows a singleton pattern to maintain the writing of logging information to the same window as opposed to writing it by opening a new window each time.

An application can potentially try to obtain an instance of this Handler at serveral places. Each such attempt will generate a new window. To avoid that a single instance is provided per application with the getInstance() method.

Constructor Summary

Constructors

Constructor	Description
LogWindowHandler()	don't call this except in logging.properties, or one would get multiple windows

Method Summary

Modifier and Type	Method	Description
void	close()
void	flush()
static LogWindowHandler	getInstance()	The getInstane method returns the singleton instance of the WindowHandler object It is synchronized to prevent two threads trying to crate an instance simultaneously.
LogWindow	getWindow()
void	publish(LogRecord record)	Publish record to window.

Methods inherited from class java.util.logging.Handler

getEncoding, getErrorManager, getFilter, getFormatter, getLevel, isLoggable, reportError, setEncoding, setErrorManager, setFilter, setFormatter, setLevel

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LogWindowHandler

public LogWindowHandler()

don't call this except in logging.properties, or one would get multiple windows

Method Detail

getInstance

public static LogWindowHandler getInstance()

The getInstane method returns the singleton instance of the WindowHandler object It is synchronized to prevent two threads trying to crate an instance simultaneously. @ return WindowHandler object

publish

public void publish(LogRecord record)

Publish record to window.

This is the overridden publish method of the abstract super class Handler. This method writes the logging information to the associated Java window. This method is synchronized to make it thread-safe. In case, there is a problem, it reports the problem with the ErrorManager, only once and silently ignores the others.

Specified by:

publish in class Handler

Parameters:

record - record to log

close

public void close()

Specified by:

close in class Handler

flush

public void flush()

Specified by:

flush in class Handler

getWindow

public LogWindow getWindow()