java多线程---顺序打印ABC的三种实现---join方法

package com.zcj.join;

public class JoinTest {
public static void main(String[] args) {
ThreadA threadA = new ThreadA();
ThreadB threadB = new ThreadB(threadA);
ThreadC threadC = new ThreadC(threadB);
threadA.start();
threadB.start();
threadC.start();
}
}

class ThreadA extends Thread{
@Override
public void run() {
// TODO Auto-generated method stub
System.out.println("A");
}

}
class ThreadB extends Thread{
private ThreadA threadA;
public ThreadB(ThreadA threadA){
this.threadA =threadA;
}
@Override
public void run() {
// TODO Auto-generated method stub
try {
threadA.join();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("B");
}

}
class ThreadC extends Thread{
private ThreadB threadB;
public ThreadC(ThreadB threadB){
this.threadB =threadB;
}
@Override
public void run() {
// TODO Auto-generated method stub
try {
threadB.join();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("C");
}
}

A
B
C