question of threads from Dan's mock

[Ana Abrantes]

This is a question on Dan's new mock:

class MyThread extends Thread { 
    public MyThread(Runnable r) {
        super(r);
    } 
    public void run() {
        System.out.print("A");
    } 
} 
class MyRunnable implements Runnable { 
    public void run() {
        System.out.print("B");
    } 
} 
class TesteThread { 
    public static void main(String[] args) { 
        new MyThread(new MyRunnable()).start(); 
    } 
} 

As a result, it prints "A".
But I can't figure out why!
If I don't have the class MyThread and used Thread instead, the result would be "B".
Does the run() method of a subclass of Thread have priority over the run() of the runnable passed as target to it?
Ana

[Sachin Tendulkar]

In the example given the run method is being over-ridden. The original run method in Thread calls the run method of the Runnable interface if the thread is passed a Runnable object.
In this case the over-riding method changes the behaviour of the run method. It simply prints "A" and never calls the run method of the Runnable interface.
As a result at run time the over-ridden run method is called and prints A.

[Marlene Miller]

Here is the run method of the Thread class.

    private Runnable target;
    public void run() {
        if (target != null) {
            target.run();
        }
    }

If this method is overridden, target.run() will not be invoked. The run() method of the Runnable object will not be executed.