Question

我想创建两个Threads。一个用于显示内容，之后它将转到等待状态。然后第二个线程应该开始执行，它应该打印状态第一个线程（即等待状态），显示后应该通知，第一个线程应该继续执行。

Answer 1

我为你创建了一个小程序。请检查它是否符合您的要求。我们可以稍后美化代码。如果不符合您的期望，请详细说明您的要求。

public class Main {
public static void main(String[] args) {
    MyThread1 th1 = new MyThread1();
    MyThread2 th2 = new MyThread2();
    //Allow thread 1 to run first
    Shareable shareable = new Shareable();
    shareable.threadToRun = th1.getName();
    th1.setAnotherThread(th2);
    th1.setShareable(shareable);
    th2.setAnotherThread(th1);
    th2.setShareable(shareable);
    th1.start();
    th2.start();
}
}
class Shareable {
    volatile String threadToRun;
}
class MyThread1 extends Thread {

private Shareable shareable;
private Thread anotherThread;

@Override
public void run() {
    synchronized (shareable) {
        waitForTurn();
        System.out.println(getName() +  " I am doing first task. After that wait for next Thread to finish.");
        shareable.threadToRun = anotherThread.getName();
        shareable.notifyAll();
        waitForTurn();
        System.out.println(getName() +  " I am doing next task now.");
    }
}

private void waitForTurn(){
    if(!shareable.threadToRun.equals(getName())){
        try {
            shareable.wait();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

public void setShareable(Shareable shareable){
    this.shareable = shareable;
}
public void setAnotherThread(Thread anotherThread){
    this.anotherThread = anotherThread;
}


}
class MyThread2 extends Thread {

private Shareable shareable;
private Thread anotherThread;

@Override
public void run() {
    synchronized (shareable) {
        waitForTurn();
        System.out.println(getName() +  " I am doing task now. Another Thread " + anotherThread.getName() + " is in state " + anotherThread.getState());
        shareable.threadToRun = anotherThread.getName();
        shareable.notifyAll();
    }
}

private void waitForTurn(){
    if(!shareable.threadToRun.equals(getName())){
        try {
            shareable.wait();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}
public void setShareable(Shareable shareable){
    this.shareable = shareable;
}
public void setAnotherThread(Thread anotherThread){
    this.anotherThread = anotherThread;
}
}

这是输出：

Thread-0 I am doing first task. After that wait for next Thread to finish.
Thread-1 I am doing task now. Another Thread Thread-0 is in state WAITING
Thread-0 I am doing next task now.

我想知道（打印）来自另一个线程的一个线程的状态......我们可以这样做吗？

1 个答案: