Java面试之线程通讯方式详解

Object lock = new Object();
// 创建线程并执行
new Thread(() -> {
    System.out.println("线程1：开始执行");
    synchronized (lock) {
        try {
            System.out.println("线程1：进入等待");
            lock.wait();
            System.out.println("线程1：继续执行");
            Thread.sleep(3000);
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }
        System.out.println("线程1：执行完成");
    }
}).start();
Thread.sleep(1000);
synchronized (lock) {
    // 唤醒线程
    System.out.println("执行 notifyAll()");
    lock.notifyAll();
}

// 创建 Condition 对象
Lock lock = new ReentrantLock();
Condition condition = lock.newCondition(); // lock 下可创建多个 Condition
// 加锁
lock.lock();
try {
    // 业务方法......
    // 1.进入等待状态
    condition.await();
    // 2.唤醒操作
    condition.signal();
} catch (InterruptedException e) {
    e.printStackTrace();
} finally {
    lock.unlock();
}

public static void main(String[] args) throws InterruptedException {
    Thread t1 = new Thread(() -> {
        LockSupport.park();
        System.out.println("线程1");
    }, "线程1");
    t1.start();
    Thread t2 = new Thread(() -> {
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("唤醒线程1");
        LockSupport.unpark(t1);
    }, "线程2");
    t2.start();
}

// 创建 Condition 对象
private Lock lock = new ReentrantLock();
// 生产者的 Condition 对象
private Condition producerCondition = lock.newCondition();
// 本篇内容出自磊哥《Java面试突击训练营》 VX：GG_Stone
// 消费者的 Condition 对象
private Condition consumerCondition = lock.newCondition();