线程再学习（6篇博客）

Java ThreadPoolExecutor的拒绝策略CallerRunsPolicy的一个潜在的大坑_明明如月的技术博客-CSDN博客_callerrunspolicy

Java ThreadPoolExecutor的拒绝策略_明明如月的技术博客-CSDN博客

ThreadPoolTaskExecutor和ThreadPoolExecutor区别_背景模版-CSDN博客_threadpooltaskexecutor

springboot中@Async多线程注解使用_背景模版-CSDN博客

 ①：根据当前服务器cpu内核，计算出核心线程数和最大线程数

②：用的线程池还是spring框架下的线程池ThreadPoolTaskExecutor

③：最大线程数和核心线程数这里保持一致

SpringBoot异步多线程调用注解@Async使用和CountDownLatch配合使用案例_背景模版-CSDN博客

@Autowired
    private Test test;
    @Override
    public List findByMonth() {
        List list = new ArrayList<>();
        for (int i =1;i<=12;i++){
            int count= baseMapper.findByMonth(i);
            list.add(count);
        }
        CountDownLatch countDownLatch = new CountDownLatch(6);
        System.out.println("开始执行多线程任务1111111111:::"+System.currentTimeMillis());
        for (int i =0;i<=5;i++){
            test.doTaskThree(countDownLatch,i);
 
        }
        try {
            countDownLatch.await();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("主线程继续执行222222222222222:::::"+Thread.currentThread().getName());
        return list;
 
 
 
 
@Component
public class Test {
    //注意这个多线程方法的类一定要加@Component注解，拿给spring容器管理
    @Async
    public void doTaskThree(CountDownLatch countDownLatch,int i) {
        long start = System.currentTimeMillis();
        try {
            Thread.sleep(10000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        long end = System.currentTimeMillis();
        System.out.println("第00" + i + "完成任务，耗时：" + (end - start) + "毫秒，线成名为::" + Thread.currentThread().getName());
        countDownLatch.countDown();
    }
 
}

 还有一种就是使用多线程中带返回的 Future结果来进行主线程的控制，大概如下，可供参考。

@Async("getTaskExector")
    public Future doTaskThree(int i) {
        long start = System.currentTimeMillis();
        try {
            Thread.sleep(10000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        long end = System.currentTimeMillis();
        System.out.println("第00" + i + "完成任务，耗时：" + (end - start) + "毫秒，线成名为::" + Thread.currentThread().getName());
        return new AsyncResult("SUCUESS");
    }
 
 
 
 
 
System.out.println("开始执行多线程任务1111111111:::"+System.currentTimeMillis());
        List> list1 = new ArrayList<>();
        for (int i =0;i<=5;i++){
            Future stringFuture = test.doTaskThree(i);
            list1.add(stringFuture);
        }
        boolean flag = false;
        while (!flag){
            for (Future future:list1){
                try {
                    String s = future.get();
                    if (s =="成功"){
                        flag = true;
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
        System.out.println("主线程继续执行222222222222222:::::"+Thread.currentThread().getName());
 

CountDownLatch、Semaphone学习_chenkaibsw的专栏-CSDN博客