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Thread: Timer expires invoke method

  1. #1
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    Default Timer expires invoke method

    Hi ,
    i want to set a timer for 5 secs and once the timer wakes up i want to invoke a method . i am checking a boolean flag of class b,once set i want to invoke the method . but the logic is not quite working ,any other simple method to do this thing??

    i have implemented this using a thread...
     
    public class a {
     
    	int seconds; 
    	Thread timer;
    	static b obj=new b();
     	public static void main(String[] args) {
     
     
     
     		Thread t1=new Thread(obj);
    t1.start();
     
    while(true){
     
    //	System.out.println(b.flag);            //..................>if i use this line the code works fine ??
    	if(b.flag)
    	{System.out.println("timer was set");
    	System.out.println("this should be true"+b.flag);
    		b.flag=false;
    		System.out.println("this should be false"+b.flag);
    	System.out.println("method");
    	System.out.println("timer cleared");
     
    	}
     
     
     
    }
     
     	}
    }
     
     
    public class b implements Runnable{
    	int seconds;
    	public static boolean flag=false;
     
     
    	public void run() {
    		while(true)
    			{
    			System.out.println("flag being set");
     
    			flag=true;
    			 	//	try{
    			 			try {
    							Thread.sleep(5000);
    						} catch (InterruptedException e) {
    							// TODO Auto-generated catch block
    							e.printStackTrace();
    						}
    			 		//}catch(Exception e){}
     
     	}}
    }


  2. #2
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    Default Re: Timer expires invoke method

    Have you looked at using the Swing Timer class. It could be easier.

    but the logic is not quite working
    Can you explain what happens or doesn't happen?

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    Default Re: Timer expires invoke method

    the logic

    if(b.flag)
    {System.out.println("timer was set");
    System.out.println("this should be true"+b.flag);
    b.flag=false;
    System.out.println("this should be false"+b.flag);
    System.out.println("method");
    System.out.println("timer cleared");

    }

    is not performed even the flag is being set

  4. #4
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    Default Re: Timer expires invoke method

    is not performed even the flag is being set
    What is the value of b.flag that is printed out when the println is uncommented?

    What was printed out when you ran it?

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    Default Re: Timer expires invoke method

    the output is like:


    flag being set
    flag being set
    flag being set


    this body:

    if(b.flag)
    {System.out.println("timer was set");
    System.out.println("this should be true"+b.flag);
    b.flag=false;
    System.out.println("this should be false"+b.flag);
    System.out.println("method");
    System.out.println("timer cleared");

    }


    is not executing
    Last edited by jack_nutt; July 11th, 2011 at 05:32 PM.

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    Default Re: Timer expires invoke method

    Here's what I get when I execute it:


    Running: D:\Java\jdk1.6.0_25\jre\bin\java.exe -Xmx512M -classpath D:\JavaDevelopment;. a

    flag being set
    timer was set
    this should be truetrue
    this should be falsefalse
    method
    timer cleared
    flag being set
    timer was set
    this should be truetrue
    this should be falsefalse
    method
    timer cleared
    flag being set
    timer was set
    this should be truetrue
    this should be falsefalse
    method
    timer cleared
    flag being set
    timer was set
    this should be truetrue
    this should be falsefalse
    method
    timer cleared

  7. #7
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    Default Re: Timer expires invoke method

    I have tried this on Eclipse and Netbeans IDE .
    I got this :


    flag being set
    timer was set
    this should be truetrue
    this should be falsefalse
    method
    timer cleared
    flag being set
    flag being set
    flag being set
    flag being set
    flag being set

  8. #8
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    Default Re: Timer expires invoke method

    Sorry, it seems to work for me.

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