java中的线程同步

package com.test;

public class Programe {

    public static void main(String[] args) throws InterruptedException {
        // TODO Auto-generated method stub
        
        System.out.println("aaaaaa");
        
        System.out.println(args.length);
        
        for(String s:args){
            System.out.println(s);

        }
        
        //test1();
        //test2();
        
        
        
          Thread t1=new Thread(){
              public void run(){
                  System.out.println("t1");
                  
              }
              
          };
          Thread t2=new Thread(){
              public void run(){
                  System.out.println("t2");
                  
              }
              
          };
          Thread t3=new Thread(){
              public void run(){
                  System.out.println("t3");
                  
              }
              
          };

          t1.start();
          t1.join();//t1执行完成后才会执行t2
          t2.start();
          t2.join();
          t3.start();
    }