Package org.apache.commons.launcher

Class ParentListener

java.lang.Object

java.lang.Thread

org.apache.commons.launcher.ParentListener

All Implemented Interfaces:

java.lang.Runnable

public class ParentListener
extends java.lang.Thread

A class for detecting if the parent JVM that launched this process has terminated.

Author:

Patrick Luby

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

java.lang.Thread.State, java.lang.Thread.UncaughtExceptionHandler

Field Summary

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Constructors

Constructor	Description
ParentListener(java.lang.String path)	Validates and caches a lock file created by the parent JVM.

Method Summary

Modifier and Type	Method	Description
void	run()	Periodically check that the parent JVM has not terminated.

Methods inherited from class java.lang.Object

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

Methods inherited from class java.lang.Thread

activeCount, checkAccess, clone, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, onSpinWait, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Constructor Detail

ParentListener

public ParentListener(java.lang.String path)
               throws java.io.IOException

Validates and caches a lock file created by the parent JVM.

Parameters:

path - the lock file that the parent JVM has an open FileOutputStream

Throws:

java.io.IOException - if the heartbeat cannot be converted into a valid File object

Method Detail

run

public void run()

Periodically check that the parent JVM has not terminated. On all platforms other than Windows, this method will check that System.in has not been closed. On Windows NT, 2000, and XP the lock file specified in the ParentListener(String) constructor is monitored as reading System.in will block the entire process on Windows machines that use some versions of Unix shells such as MKS, etc. No monitoring is done on Window 95, 98, and ME.

Specified by:

run in interface java.lang.Runnable

Overrides:

run in class java.lang.Thread