Threaded Java code issue

Question

I am a beginner here and started learning java programming.

I wrote a program to try threading. In one class i wrote a program to display numbers from one to 100 and in another class to display number from 999 to 100. Now in the the main i have created an object reference for both the class(r1,r2)) and created a object for thread and passed(r1,r2-object reference of my class) them as a parameter. Now the output i get is not as expected in some way i feel my second thread is not getting executed. I am not sure if there is anything wrong with my logic or the program. Any help/advice would be appreciated. My code below for reference.

Class 1:

public class Run implements Runnable {

@Override
public void run() {

    for (int i = 0; i < 100; i++) {
        try {

            Thread.sleep(200);
        } catch (InterruptedException ex) {
            Logger.getLogger(Run.class.getName()).log(Level.SEVERE, "...", ex);
        }
        System.out.println(i);
    }
}
}

Class 2: public class Run2 extends Thread {

public void run2() {

    for(int i=999;i>0;i--){
        try {

            Thread.sleep(500);
        } catch (InterruptedException ex) {
            Logger.getLogger(Run2.class.getName()).log(Level.SEVERE, "....", ex);
        }
        System.out.println(i);


    }

}
} 

Main class:

public class Threading {

/**
 * @param args the command line arguments
 */
public static void main(String[] args) {

    Run r= new Run();
    Thread t1=new Thread(r);
     t1.start();

    Run2 r2=new Run2();
    Thread t2=new Thread(r2);

    t2.start();


}

}

Answer 1

Rename Run2's method run2 to run. You're subclassing Thread, so you get a run method that doesn't do anything (actually it checks to see if it was passed in a target runnable, in which case it calls run on the target, but since the target is null it does nothing), and that's what's getting run.

Make a habit of implementing Runnable instead of extending Thread, and use the @Override annotation to catch mistakes where you think you're overriding something but you're not.

Answer 2

Your class Run2's method should be named run and not run2.