//线程
     public class test102 extends Thread{
         public void run(){
             while (true){
                 System.out.println("我是线程1"+this.getName());
                 try {
                     Thread.sleep( 1000 );
                 }catch (InterruptedException e){
                     e.printStackTrace();
                 }
             }
         }
     }    //线程
     public class test103 extends Thread{
         public void run(){
             while (true){
                 System.out.println("我是线程2"+this.getName());
                 try {
                     Thread.sleep( 1000 );
                 }catch (InterruptedException e){
                     e.printStackTrace();
                 }
             }
         }
     }测试类
    public class test104 {
         public static void main(String[] args){
             test102 one=new test102();
             test103 two=new test103();
             one.start();
             two.start();
             System.out.println( "我是主方法" );
         }
     }