多线程测试服务
1.新建一个核心数为100 的线程池
ExecutorService service = Executors.newFixedThreadPool(100);
2.执行一个阻塞不大的任务
service.execute(()->{
try {
for (int i =0; i <100; i++) {
Thread.sleep(100);
System.out.println("我阻塞了100ms");
}
}catch (InterruptedException e) {
e.printStackTrace();
}
});
测试发现什么都没有打印
查阅资料发现
junit 单元测试当主线程执行完毕，主线程会关闭，并且关闭子线程
解决方法
使用在主线程中使用join 等待子线程执行完
try {
Thread.currentThread().join();
} catch (InterruptedException e) {
e.printStackTrace();
}
结果
Join方法.png
使用CountDownLatch 等待
2.1 任务类RunableTask
public class RunableTask implements Runnable {
private CountDownLatch countDownLatch;
public RunableTask(CountDownLatch countDownLatch) {
this.countDownLatch = countDownLatch;
}
@Override
public void run() {
try {
Thread.sleep(100);
System.out.println("我阻塞了100ms");
} catch (InterruptedException e) {
e.printStackTrace();
}finally {
countDownLatch.countDown();
}
}
}
2.2 测试方法
@Test
public void runCountDown() {
for (int i = 0; i < 100; i++) {
service.execute(new RunableTask(countDownLatch));
}
try {
countDownLatch.await();
log.info("执行成功");
} catch (InterruptedException e) {
e.printStackTrace();
log.log(Level.WARNING,e,()->"抛出中断异常");
}
}
结果
CoutDownLautch 起效果.png
当然还可以让主线程睡眠来等待子线程
github地址
