org.xmlBlaster.util
Class SignalCatcher

java.lang.Object
  org.xmlBlaster.util.SignalCatcher

All Implemented Interfaces:

java.lang.Runnable

public class SignalCatcher
extends java.lang.Object
implements java.lang.Runnable

SignalCatcher catches Ctrl-C and does the desired action.

Works only with JDK 1.3 and above, we check with reflection the availability to still be JDK 1.2 compatible.

Author:

Marcel Ruff.

Field Summary

private I_SignalListener	listener
private static java.util.logging.Logger	log
private boolean	runDummy
private static SignalCatcher	theSignalCatcher
private java.lang.Thread	thread

Constructor Summary

SignalCatcher()

Method Summary

boolean	catchSignals() Add shutdown hook.
boolean	hasListener()
static SignalCatcher	instance()
void	register(I_SignalListener listener) You need to call init() after construction.
boolean	removeSignalCatcher()
void	run() This is invoked on exit

Methods inherited from class java.lang.Object

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

Field Detail

log

private static java.util.logging.Logger log

theSignalCatcher

private static SignalCatcher theSignalCatcher

thread

private java.lang.Thread thread

listener

private I_SignalListener listener

runDummy

private boolean runDummy

Constructor Detail

SignalCatcher

public SignalCatcher()

Method Detail

instance

public static SignalCatcher instance()

hasListener

public boolean hasListener()

register

public void register(I_SignalListener listener)

You need to call init() after construction. Example for a hook:

  class Shutdown extends Thread {
    public void run() {
       System.exit(0);
    }
  }
  SignalCatcher c = SignalCatcher.instance();
  c.register(new Shutdown());
  c.catchSignals();
  ...
  c.removeSignalCatcher();
 

Throws:

java.lang.IllegalArgumentException - if other listener exists

catchSignals

public boolean catchSignals()

Add shutdown hook.

Catch signals, e.g. Ctrl C to stop xmlBlaster.
Uses reflection since only JDK 1.3 supports it.

NOTE: On Linux build 1.3.0, J2RE 1.3.0 IBM build cx130-20000815 (JIT enabled: jitc) fails with Ctrl-C

Returns:

true: Shutdown hook is established

removeSignalCatcher

public boolean removeSignalCatcher()

Returns:

true on success

run

public void run()

This is invoked on exit

Specified by:

run in interface java.lang.Runnable