er.extensions.appserver

Class ERXShutdownHook

java.lang.Object

java.lang.Thread

er.extensions.appserver.ERXShutdownHook

All Implemented Interfaces:

Runnable

public abstract class ERXShutdownHook
extends Thread

Use this to register shutdown hooks instead of directly using Runtime.addShutdownHook(). The net effect is that there will be a specific log file entry AFTER all other shutdown hooks have completed, notifying a watching user that shutdown of the application has indeed completed, which says:

APPLICATION SHUTDOWN SEQUENCE COMPLETE

on a single line. After you see this line in the application's log file, you can be pretty sure that the process is indeed terminated. This notification works even if there are no other shutdown hooks registered, if you ensure that this class is loaded at all, e.g. by calling the no-op useMe() method somewhere (ERXApplication does this for you if you extend that).

Usage (e.g. in your Application class constructor):

 new ERXShutdownHook() {
      @Override
     public void hook() {
         // do something
     }
 };
 

CAUTION

You should not use this class when deploying the application as a J2EE servlet as it may interfere with other servlets running in the same VM. To disable this feature you have to provide the following start parameter to the java VM: -Der.extensions.ERXApplication.enableERXShutdownHook=false

Author:

Maik Musall, maik@selbstdenker.ag

Nested Class Summary

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

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Constructors

Constructor and Description
ERXShutdownHook() Construct a new nameless shutdown hook and register it.
ERXShutdownHook(String hookName) Construct a new named shutdown hook and register it.

Method Summary

Modifier and Type	Method and Description
abstract void	hook() This is where you implement what is supposed to be run at shutdown time.
static void	initERXShutdownHook()
void	run()
static void	useMe() Call this in your app constructor if you have no other shutdown hooks.

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, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Constructor Detail

ERXShutdownHook

public ERXShutdownHook()

Construct a new nameless shutdown hook and register it. It is recommended to use named hooks wherever possible for easier debugging.

ERXShutdownHook

public ERXShutdownHook(String hookName)

Construct a new named shutdown hook and register it.

Parameters:

hookName - hook name

Method Detail

initERXShutdownHook

public static void initERXShutdownHook()

useMe

public static void useMe()

Call this in your app constructor if you have no other shutdown hooks. If you don't call anything, this class will not be loaded at all and won't work. ERXApplication calls this, so no need to do this if you're extending that.

run

public final void run()

Specified by:

run in interface Runnable

Overrides:

run in class Thread

hook

public abstract void hook()

This is where you implement what is supposed to be run at shutdown time.