我要创建两个java线程（一个线程乘数另一个线程添加数字）答案

【问题标题】：im going to create two java threads(one thread to multiply numbers another thread to add numbers)我要创建两个java线程（一个线程乘数另一个线程添加数字）
【发布时间】：2020-08-31 22:16:37
【问题描述】：

我必须得到这样的输出：

这是我的代码。没有错误。它以PlusThread 开头并打印第一行。然后它会释放锁。之后MultiplyThread 开始运行。它将打印所有行而不是通知PlusThread。

public class TestThread {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Object lock = new Object();
        PlusThread pT = new PlusThread(lock, 2, 10);
        pT.start();
        MultiplyThread mT = new MultiplyThread(lock, 2, 10);
        mT.start();
    }
}

class PlusThread extends Thread {

    Object lock;
    int start, range;

    public PlusThread(Object lock, int start, int range) {
        super();
        this.lock = lock;
        this.start = start;
        this.range = range;
    }

    @Override
    public void run() {
        synchronized (this) {
            for (int i = start; i <= range; ++i) {

                System.out.println(i + " + " + i + " = " + (i + i));
                try {
                    this.wait();

                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
}

class MultiplyThread extends Thread {
    Object lock;
    int start, range;

    public MultiplyThread(Object lock, int start, int range) {

        this.lock = lock;
        this.start = start;
        this.range = range;
    }

    @Override
    public void run() {
        synchronized (this) {
            for (int j = start; j <= range; ++j) {
                System.out.println(j + " * " + j + " = " + (j * j));
                this.notify();
            }
        }
    }
}

这是我的输出：

【问题讨论】：

检查这个问题stackoverflow.com/questions/17472572/…它可能会有所帮助！
不幸的是，Java 之神选择了synchronized 作为锁定锁的构造，因为锁不用于同步或协调不同线程的活动。锁仅用于一个目的：通过防止线程同时访问相同的变量来防止线程相互干扰。对于任何其他目的，您应该使用更高级别的同步对象；信号量、屏障、阻塞队列等

标签： java multithreading java-threads thread-synchronization

【解决方案1】：

这会起作用

static class PlusThread extends Thread {

    final Object lock;
    int start, range;

    public PlusThread(Object lock, int start, int range) {
        super();
        this.lock = lock;
        this.start = start;
        this.range = range;
    }

    @Override
    public void run() {
        synchronized (lock) {
            for (int i = start; i <= range; ++i) {
                try {
                    lock.wait();
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                System.out.println(i + " + " + i + " = " + (i + i));
                lock.notify();
            }
        }
    }
}

static class MultiplyThread extends Thread {
    final Object lock;
    int start, range;

    public MultiplyThread(Object lock, int start, int range) {

        this.lock = lock;
        this.start = start;
        this.range = range;
    }

    @Override
    public void run() {
        synchronized (lock) {
            for (int j = start; j <= range; ++j) {
                System.out.println(j + " * " + j + " = " + (j * j));
                lock.notify();
                try {
                    lock.wait();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

【讨论】：

【解决方案2】：

try this:

public class TestThread {
    static Object lock = new Object();
    public static void main(String[] args) {
        // TODO Auto-generated method stub

        PlusThread pT = new PlusThread(lock, 2, 10);
        pT.start();
        MultiplyThread mT = new MultiplyThread(lock, 2, 10);
        mT.start();
    }
}

class PlusThread extends Thread {

    Object lock;
    int start, range;

    public PlusThread(Object lock, int start, int range) {
        super();
        this.lock = lock;
        this.start = start;
        this.range = range;
    }

    @Override
    public void run() {
        synchronized (lock) {
            for (int i = start; i <= range; ++i) {

                System.out.println(i + " + " + i + " = " + (i + i));
                try {
                    lock.notify();
                    lock.wait();

                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }

            }
        }

    }

}

class MultiplyThread extends Thread {
    Object lock;
    int start, range;

    public MultiplyThread(Object lock, int start, int range) {

        this.lock = lock;
        this.start = start;
        this.range = range;
    }

    @Override
    public void run() {
        synchronized (lock) {
            for (int j = start; j <= range; ++j) {

                System.out.println(j + " * " + j + " = " + (j * j));
                lock.notify();
                try {
                    lock.wait();
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }

            }

        }

    }
}

【讨论】：

谢谢您，先生！它可以工作..但它不会终止控制台