Correct way to stop thread inside its own run method?

[Alan Smith]

Hi,

What is the correct way to stop a thread inside its own run method? Is this possible? For example, the following does not work:

public class Main {
    public static void main(String[] args) {
        
        Counter c = new Counter("counterThread");
        c.getThread().start();

        System.out.println("My name");
        System.out.println("is");
        System.out.println("Alan");

    }
}

class Counter implements Runnable{
    
    private Thread t;
    
    public Counter(String threadName){
        t = new Thread(this, threadName);
    }

    @Override
    public void run() {
        
        for(int i=0;i<=10;i++){
                System.out.println(t.getName() + " " + i);
                if(i>5){
                    System.out.println("i is greater than 5, interrupting thread!");
                    getThread().interrupt();
                }
        }
        
    }
    
    public Thread getThread(){
        return t;
    }
    
}

The output I get is something like this:

My name
counterThread 0
is
counterThread 1
counterThread 2
Alan
counterThread 3
counterThread 4
counterThread 5
counterThread 6
i is greater than 5, interrupting thread!
counterThread 7
i is greater than 5, interrupting thread!
counterThread 8
i is greater than 5, interrupting thread!
counterThread 9
i is greater than 5, interrupting thread!
counterThread 10
i is greater than 5, interrupting thread!

Any ideas?

Edit: using return; instead of getThread().interrupt(); works, but is probably not the correct way.

[William Brogden]

Exiting the run method using return is the preferred approach.

A search for "java thread life cycle" should find you some useful tutorials.

Bill

[Piet Souris]

and if you want to return when an interrupt is received, simply check for 'isInterrupted()',
for instance in line 25: for (int i = 0; i <= 10 && !isInterrupted(); i++) {...}

Greetz,
Piet

[Alan Smith]

Thanks for the info guys. I will mark this resolved.