general question on threads?

[gurpeet singh]

consider the code snippet given below :

class MyRunnable impelements Runnable{

public void run(){ //more code here }


}

class Play{
public static void main(String... args)
{
MyRunnable r = new MyRunnable();
Thread t1= new Thread(r);
Thread t2= new Thread(r);
t1.start();
t2.start();
}
}

here we are creating two threads and they are both targeting same runnable object viz "r". in other words both the threads are invoking code ON single runnable object. my question is how to do exaclty same thing if our class extends Thread class . in other words how to make 2 threads which invokes the run method of the same thread object??

[Seetharaman Venkatasamy]

change implements Runnable to extends Thread . that is the only change you required.

[gurpeet singh]

please refer the link http://docs.oracle.com/javase/6/docs/api/java/lang/Thread.html#run(). the javadocs for the run() method says that

public void run()
If this thread was constructed using a separate Runnable run object, then that Runnable object's run method is called; otherwise, this method does nothing and returns.
Subclasses of Thread should override this method.

what does it mean by SEPARATE RUNNABLE RUN OBJECT ?

Second part of my question is that suppose i have following snippet of code :

public MyRunnable implements Runnable {

public void run(){}
}

public class Play{

public static void main(String... args)
{
MyRunnable r = new MyRunnable();
Thread t = new Thread(r);    // is "r" the separate runnable object the above javadoc is talking about ?
t.start();                // it will invoke r's run method as said by javadocs above .
}
}

as mentioned in comments, is "r" the separate runnable object the above javadoc is talking about ?

thirdly, if we have something like this

public class Mythread extends Thread{
public void run()
{
}
public static void main(String...args)
{

Mythread t = new Mythread();             // here is t the target runnable as said by above javadocs ?
t.start();       

}
}

here what is target runnable ? is it t (since t also implements Runnable) ?