Java線程中的join使用實例

JDK中解釋為 Waits for this thread to die. 等待本線程結束后，下一個線程才可以運行。

實例要求：

現在有T1、T2、T3三個線程，你怎樣保證T2在T1執行完后執行，T3在T2執行完后執行

實現代碼：

package com.st.lesson02;

public class Test01 {
    //1.現在有T1、T2、T3三個線程，你怎樣保證T2在T1執行完后執行，T3在T2執行完后執行
    public static void main(String[] args) throws InterruptedException {
        Thread th1 = new Thread01();
        Thread th2 = new Thread02();
        Thread th3 = new Thread03();
        th1.start();
        th1.join();
        System.out.println("Thread01運行結束。。。");
        th2.start();
        th2.join();
        System.out.println("Thread02運行結束。。。");
        th3.start();
        th3.join();
        System.out.println("Thread03運行結束。。。");
        System.out.println("------主函數-------");
    }
}
class Thread01 extends Thread{
    
    public void run() {
        System.out.println("Thread01...running...");
        try {
            Thread.sleep(2000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}
class Thread02 extends Thread{
    public void run() {
        System.out.println("Thread02...running...");
        try {
            Thread.sleep(500);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        
    }
}
class Thread03 extends Thread{
    public void run() {
        System.out.println("Thread03...running...");
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        
    }
}

運行效果圖：