Java线程Join方法

Question

Join 方法如何在 Thread 中工作。如果在run方法中写join方法那么就会陷入死锁。只需要了解其发生原因即可。

代码片段:

public class ThreadSchuduling extends Thread{
    static ThreadSchuduling threadObj3;
    public ThreadSchuduling(){
        System.out.println("Default Constructor");
    }
    public ThreadSchuduling(String name){
        System.out.println("Parameter Constructor");
    }
    public void run(){
        try{
            threadObj3.join();
        }catch(Exception e){
            System.out.println("Error in RUN "+e);
        }
        System.out.println(Thread.currentThread().getName());
        for(int i = 0; i < 10; i++){
            System.out.println("Value is = "+i);
        }

    }
    public static void main(String[] args) {
        ThreadSchuduling threadObj1 = new ThreadSchuduling("Thread1");
        ThreadSchuduling threadObj2 = new ThreadSchuduling("Thread2");
        threadObj3 = new ThreadSchuduling("Thread3");
        ThreadSchuduling threadObj4 = new ThreadSchuduling("Thread4");

            threadObj1.start();
            threadObj2.start();
            threadObj3.start();
            System.out.println("Thread 3 is started");
            threadObj4.start();
            try{
            threadObj3.join();

        }catch(Exception e){
            System.out.println("Errpr "+e);
        }
        System.out.println("Main Method completed");
    }

}

我只想在线程1和线程2之前完成线程3

Answer 1

您还没有解释 threadObj3 是什么...这是对同一线程的引用吗？如果是这样，那么它会陷入死锁是可以理解的 - 它会等待直到完成，但它不会这样做，因为它正在等待!

您实际上想要实现什么目标？