Several methods of creating thread classes

import java.util.concurrent.Callable;
import java.util.concurrent.FutureTask;

public class Test1 {
    public static void main(String[] args) throws Exception {
        // Create method 1  Create thread class inheritance Thread class 
        MyThread m1=new MyThread();
        m1.start();
        // Create a thread method 2; Create a thread task class MyRunable Realization Runable Interface   take Runable Object to Thread Handle 
        MyRunable m2=new MyRunable();
        Thread mm2=new Thread(m2);
        mm2.start();
        // establish Runable Anonymous inner class objects are given to Thread
        Runnable runnable=new Runnable() {
            @Override
            public void run() {
                System.out.println(" Sub thread 3 starts running ");
            }
        };
        new Thread(runnable).start();
        // Method 3 ： utilize Callable And FutureTask Interface implementation 
        MyCallable callable=new MyCallable();
        FutureTask futureTask=new FutureTask(callable);
        new Thread(futureTask).start();
        System.out.println(futureTask.get());
    }
}
class MyThread extends Thread{
    @Override
    public void run(){
        System.out.println(" Sub thread 1 starts running ");
    }
}

class MyRunable implements Runnable{
    @Override
    public void run() {
        System.out.println(" Sub thread 2 starts running ");
    }
}
class MyCallable implements Callable{
    @Override
    public Object call() throws Exception {
        return " Sub thread 4 starts running ";
    }
}