多线程测试 n 个线程同时开始 并发辅助测试

// 不多 BB,上代码:==>
package com.baidu.test.junit;

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import com.taikang.Application;

/**

• 多线程 Junit 单元测试
• @author LiuDong

*/
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = Application.class)
public class JunitThreadTest {

/**
 * 模拟100米赛跑,n名选手已经准备就绪,只等一声令下,当所有人到达终点时,比赛结束
 * @param args
 * @throws Exception
 */
public static void main(String[] args) throws Exception {
	// 选手数量
	final int num = 20;
	// 开始的倒数锁
	final CountDownLatch begin = new CountDownLatch(1);
	// 结束的倒数锁
	final CountDownLatch end = new CountDownLatch(num);
	// 十名选手
	final ExecutorService exec = Executors.newFixedThreadPool(num);

	for (int i = 0; i < num; i++) {
		final int no = i + 1;
		Runnable run = new Runnable() {
			// 重写run()方法
			@Override
			public void run() {
				try {
					// 如果当前计数为零,则此方法立即返回
					// 等待
					begin.await();
					// 可以写点循环控制每个运动动员跑多少圈(长跑)
					Thread.sleep((long) (Math.random() * 10000));
					System.out.println("NO." + no + "arrived");
				} catch (InterruptedException e) {
					e.printStackTrace();
				} finally {
					// 每个选手到达终点时,end就减一
					end.countDown();
				}
			}
		};
		exec.submit(run);
	}
	System.out.println("Game Start");
	// begin减一,开始游戏
	begin.countDown();
	// 等待end变为0,即所有选手都到达终点
	end.await();
	System.out.println("Game Over");
	exec.shutdown();
}
​

}