Package ca.cgjennings.apps.util

Class InstanceController

java.lang.Object

ca.cgjennings.apps.util.InstanceController

All Implemented Interfaces:

java.lang.Runnable

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

Prevents multiple instances of a program from running. On startup, the class's makeExclusive method will be called with any file parameters from the command line. This method will attempt to create a server on a certain port. If it fails, it assumes a previous instance has already registered the port. In this case, it sends a message to the existing server to identify itself and to specify which file(s) to were requested on this instance's command line. This method will return true if the calling instance should keep running after the method returns, or false if it should stop. A false return value indicates that the program arguments were successfully sent to an instance that is already running. A value of true indicates that the current instance is the first, exclusive instance, or that the method is unable to verify whether an existing instance is running.

Author:

Chris Jennings

Method Summary

Modifier and Type	Method	Description
protected static void	callListener(InstanceControllerListener l, boolean initial, java.lang.String[] args)
static boolean	makeExclusive(java.lang.String programName, int port, java.lang.String[] args, InstanceControllerListener listener)
void	run()
static void	stopExclusion()

Methods inherited from class java.lang.Object

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

Method Detail

makeExclusive

public static boolean makeExclusive(java.lang.String programName,
                                    int port,
                                    java.lang.String[] args,
                                    InstanceControllerListener listener)

callListener

protected static void callListener(InstanceControllerListener l,
                                   boolean initial,
                                   java.lang.String[] args)

stopExclusion

public static void stopExclusion()

run

public void run()

Specified by:

run in interface java.lang.Runnable