讓線程等待和喚醒的3種方式

使用Object

package study;

public class Test {
	public static void main(String[] args) throws InterruptedException {
		Object lock = new Object();
		Thread t1 = new Thread(() -> {
			System.out.println("進入線程t1");
			synchronized (lock) {
				System.out.println("線程t1準備進入等待狀態");
				try {
					lock.wait();
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
			System.out.println("線程t1撤出了");
		});
		t1.start();
		Thread.sleep(1000);
		System.out.println("主線程休眠完畢,準備喚醒t1線程");
		synchronized (lock) {
			lock.notify();
		}
	}
}

使用Condition

package study;

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantLock;

public class Test1 {
	static ReentrantLock lock = new ReentrantLock(); 
	static Condition condition = lock.newCondition();
	public static void main(String[] args) {
		Thread t1 = new Thread(() -> {
			lock.lock();
			System.out.println("線程t1開始執行");
			try {
				try {
					System.out.println("線程t1在condition上等待");
					condition.await();
				} catch (Exception e) {
					e.printStackTrace();
				}
			} finally {
				lock.unlock();
			}
			System.out.println("線程t1執行完畢");
		});
		t1.start();
		System.out.println("主線程執行中");
		try {
			lock.lock();
			System.out.println("主線程準備喚醒t1線程");
			condition.signal();
		} finally {
			lock.unlock();
		}
	}
}

使用lockSupport

package study;
import java.util.concurrent.locks.LockSupport;


public class Test2 {
	public static void main(String[] args) throws InterruptedException {
		Thread t1 = new Thread(() -> {
			System.out.println("線程t1開始執行");
			System.out.println("準備使用lockSupport讓t1線程等待");
			LockSupport.park();
			System.out.println("線程t1結束等待,執行完畢");
		});
		t1.start();
		System.out.println("主線程準備睡眠2秒");
		Thread.sleep(2000);
		System.out.println("主線程睡眠完畢,準備喚醒t1線程");
		LockSupport.unpark(t1);
	}
}

3種方式的區別