线程执行顺序

三个线程T1，T2,T3，如何保证线程T2在T1执行后执行,T3在T2执行后执行。

利用join()方法。

package 多线程并发;

/**
 * Created by z84102272 on 2018/7/17.
 */
public class ThreadJoin extends Thread{
    public ThreadJoin(String name){
        setName(name);
    }
    @Override
    public void run() {
        for (int i = 0;i < 5;i++){
            try {
                System.out.println(Thread.currentThread().getName());
                Thread.sleep(1000);
            }catch (InterruptedException e){
                e.printStackTrace();
            }
        }
    }

    public static void main(String[] args){
        ThreadJoin T1 = new ThreadJoin("T1");
        ThreadJoin T2 = new ThreadJoin("T2");
        ThreadJoin T3 = new ThreadJoin("T3");
        try {
            T1.start();
            T1.join();
            T2.start();
            T2.join();
            T3.start();
            T3.join();
        }catch (InterruptedException e){
            e.printStackTrace();
        }
    }
}