1
Now that the system is becoming more and more complex, many interfaces have slowed down. At this time, it is thought that the thread pool can be used to process some time-consuming operations without affecting the operation of the system.

New Spring Boot project

1. ExecutorConfig.xml

Create a new thread pool configuration file.

@Configuration
@EnableAsync
public class ExecutorConfig {

    private static final Logger logger = LoggerFactory.getLogger(ExecutorConfig.class);

    @Value("${async.executor.thread.core_pool_size}")
    private int corePoolSize;
    @Value("${async.executor.thread.max_pool_size}")
    private int maxPoolSize;
    @Value("${async.executor.thread.queue_capacity}")
    private int queueCapacity;
    @Value("${async.executor.thread.name.prefix}")
    private String namePrefix;

    @Bean(name = "asyncServiceExecutor")
    public Executor asyncServiceExecutor() {
        logger.info("start asyncServiceExecutor");
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        //配置核心线程数
        executor.setCorePoolSize(corePoolSize);
        //配置最大线程数
        executor.setMaxPoolSize(maxPoolSize);
        //配置队列大小
        executor.setQueueCapacity(queueCapacity);
        //配置线程池中的线程的名称前缀
        executor.setThreadNamePrefix(namePrefix);

        // rejection-policy:当pool已经达到max size的时候,如何处理新任务
        // CALLER_RUNS:不在新线程中执行任务,而是有调用者所在的线程来执行
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        //执行初始化
        executor.initialize();
        return executor;
    }
}

2. application.yml

@Value is configured in application.yml, you can refer to the configuration

# 异步线程配置
async:
  executor:
    thread:
      # 配置核心线程数
      core_pool_size: 10
      # 配置最大线程数
      max_pool_size: 20
      # 配置队列大小
      queue_capacity: 99999
      # 配置线程池中的线程的名称前缀
      name:
        prefix: async-service-

3. AsyncService.java

Create a Service interface, which is an asynchronous thread interface, and write the method to its implementation class

public interface AsyncService {

    /** 
      * 执行异步任务的方法,参数自己可以添加
      */
    void executeAsync();
}

4. AsyncServiceImpl.java

Implementation class, used to write business logic

@Service
public class AsyncServiceImpl implements AsyncService {

    private static final Logger logger = LoggerFactory.getLogger(AsyncServiceImpl.class);

    @Override
    @Async("asyncServiceExecutor")
    public void executeAsync() {
        logger.info("start executeAsync");

        System.out.println("异步线程执行开始了");
        System.out.println("可以将耗时的操作放到这里执行了");

        logger.info("end executeAsync");
    }
}

++ Asynchronize the service of the Service layer, and add the annotation @Async("asyncServiceExecutor") to the executeAsync() method. The asyncServiceExecutor method is the method name in the previous ExecutorConfig.java, indicating that the thread pool entered by the executeAsync method is created by the asyncServiceExecutor method . ++

5. AsyncController.java

Inject AsyncService into the controller and call the method in it

@Autowired
private AsyncService asyncService;

@GetMapping("/async")
public void async(){
    asyncService.executeAsync();
}

6. Test with Postman

Print log in

2021-06-16 22:15:47.655  INFO 10516 --- [async-service-5] c.u.d.e.executor.impl.AsyncServiceImpl   : start executeAsync
异步线程执行开始了
可以将耗时的操作放到这里执行了
2021-06-16 22:15:47.655  INFO 10516 --- [async-service-5] c.u.d.e.executor.impl.AsyncServiceImpl   : end executeAsync
2021-06-16 22:15:47.770  INFO 10516 --- [async-service-1] c.u.d.e.executor.impl.AsyncServiceImpl   : start executeAsync
异步线程执行开始了
可以将耗时的操作放到这里执行了
2021-06-16 22:15:47.770  INFO 10516 --- [async-service-1] c.u.d.e.executor.impl.AsyncServiceImpl   : end executeAsync
2021-06-16 22:15:47.816  INFO 10516 --- [async-service-2] c.u.d.e.executor.impl.AsyncServiceImpl   : start executeAsync
异步线程执行开始了
可以将耗时的操作放到这里执行了
2021-06-16 22:15:47.816  INFO 10516 --- [async-service-2] c.u.d.e.executor.impl.AsyncServiceImpl   : end executeAsync
2021-06-16 22:15:48.833  INFO 10516 --- [async-service-3] c.u.d.e.executor.impl.AsyncServiceImpl   : start executeAsync
异步线程执行开始了
可以将耗时的操作放到这里执行了
2021-06-16 22:15:48.834  INFO 10516 --- [async-service-3] c.u.d.e.executor.impl.AsyncServiceImpl   : end executeAsync
2021-06-16 22:15:48.986  INFO 10516 --- [async-service-4] c.u.d.e.executor.impl.AsyncServiceImpl   : start executeAsync
异步线程执行开始了
可以将耗时的操作放到这里执行了
2021-06-16 22:15:48.987  INFO 10516 --- [async-service-4] c.u.d.e.executor.impl.AsyncServiceImpl   : end executeAsync

So far, the simple thread pool has been implemented.

5. Print out the running status of the current thread pool

5.1 VisiableThreadPoolTaskExecutor.java

public class VisiableThreadPoolTaskExecutor extends ThreadPoolTaskExecutor {


    private static final Logger logger = LoggerFactory.getLogger(VisiableThreadPoolTaskExecutor.class);

    private void showThreadPoolInfo(String prefix) {
        ThreadPoolExecutor threadPoolExecutor = getThreadPoolExecutor();

        if (null == threadPoolExecutor) {
            return;
        }

        logger.info("{}, {},taskCount [{}], completedTaskCount [{}], activeCount [{}], queueSize [{}]",
                this.getThreadNamePrefix(),
                prefix,
                threadPoolExecutor.getTaskCount(),
                threadPoolExecutor.getCompletedTaskCount(),
                threadPoolExecutor.getActiveCount(),
                threadPoolExecutor.getQueue().size());
    }

    @Override
    public void execute(Runnable task) {
        showThreadPoolInfo("1. do execute");
        super.execute(task);
    }

    @Override
    public void execute(Runnable task, long startTimeout) {
        showThreadPoolInfo("2. do execute");
        super.execute(task, startTimeout);
    }

    @Override
    public Future<?> submit(Runnable task) {
        showThreadPoolInfo("1. do submit");
        return super.submit(task);
    }

    @Override
    public <T> Future<T> submit(Callable<T> task) {
        showThreadPoolInfo("2. do submit");
        return super.submit(task);
    }

    @Override
    public ListenableFuture<?> submitListenable(Runnable task) {
        showThreadPoolInfo("1. do submitListenable");
        return super.submitListenable(task);
    }

    @Override
    public <T> ListenableFuture<T> submitListenable(Callable<T> task) {
        showThreadPoolInfo("2. do submitListenable");
        return super.submitListenable(task);
    }
}

5.2 Modify asyncServiceExecutor.java

Modify the asyncServiceExecutor method of ExecutorConfig.java, change ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor() to ThreadPoolTaskExecutor executor = new VisiableThreadPoolTaskExecutor()

@Bean(name = "asyncServiceExecutor")
    public Executor asyncServiceExecutor() {
        logger.info("start asyncServiceExecutor");
        //在这里修改
        ThreadPoolTaskExecutor executor = new VisiableThreadPoolTaskExecutor();
        //配置核心线程数
        executor.setCorePoolSize(corePoolSize);
        //配置最大线程数
        executor.setMaxPoolSize(maxPoolSize);
        //配置队列大小
        executor.setQueueCapacity(queueCapacity);
        //配置线程池中的线程的名称前缀
        executor.setThreadNamePrefix(namePrefix);

        // rejection-policy:当pool已经达到max size的时候,如何处理新任务
        // CALLER_RUNS:不在新线程中执行任务,而是有调用者所在的线程来执行
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        //执行初始化
        executor.initialize();
        return executor;
    }

5.3 Test with Postman

2021-06-16 22:23:30.951  INFO 14088 --- [nio-8087-exec-2] u.d.e.e.i.VisiableThreadPoolTaskExecutor : async-service-, 2. do submit,taskCount [0], completedTaskCount [0], activeCount [0], queueSize [0]
2021-06-16 22:23:30.952  INFO 14088 --- [async-service-1] c.u.d.e.executor.impl.AsyncServiceImpl   : start executeAsync
异步线程执行开始了
可以将耗时的操作放到这里执行了
2021-06-16 22:23:30.953  INFO 14088 --- [async-service-1] c.u.d.e.executor.impl.AsyncServiceImpl   : end executeAsync
2021-06-16 22:23:31.351  INFO 14088 --- [nio-8087-exec-3] u.d.e.e.i.VisiableThreadPoolTaskExecutor : async-service-, 2. do submit,taskCount [1], completedTaskCount [1], activeCount [0], queueSize [0]
2021-06-16 22:23:31.353  INFO 14088 --- [async-service-2] c.u.d.e.executor.impl.AsyncServiceImpl   : start executeAsync
异步线程执行开始了
可以将耗时的操作放到这里执行了
2021-06-16 22:23:31.353  INFO 14088 --- [async-service-2] c.u.d.e.executor.impl.AsyncServiceImpl   : end executeAsync
2021-06-16 22:23:31.927  INFO 14088 --- [nio-8087-exec-5] u.d.e.e.i.VisiableThreadPoolTaskExecutor : async-service-, 2. do submit,taskCount [2], completedTaskCount [2], activeCount [0], queueSize [0]
2021-06-16 22:23:31.929  INFO 14088 --- [async-service-3] c.u.d.e.executor.impl.AsyncServiceImpl   : start executeAsync
异步线程执行开始了
可以将耗时的操作放到这里执行了
2021-06-16 22:23:31.930  INFO 14088 --- [async-service-3] c.u.d.e.executor.impl.AsyncServiceImpl   : end executeAsync
2021-06-16 22:23:32.496  INFO 14088 --- [nio-8087-exec-7] u.d.e.e.i.VisiableThreadPoolTaskExecutor : async-service-, 2. do submit,taskCount [3], completedTaskCount [3], activeCount [0], queueSize [0]
2021-06-16 22:23:32.498  INFO 14088 --- [async-service-4] c.u.d.e.executor.impl.AsyncServiceImpl   : start executeAsync
异步线程执行开始了
可以将耗时的操作放到这里执行了
2021-06-16 22:23:32.499  INFO 14088 --- [async-service-4] c.u.d.e.executor.impl.AsyncServiceImpl   : end executeAsync

You can see the above async-service-, 2. do submit, taskCount [3], completedTaskCount [3], activeCount [0], queueSize [0] information about threads are all printed.

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周兆东
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一个java小白的成长之路。。。