@Configuration
@EnableAsync
public class AsyncConfiguration {

}

@Component
@Slf4j
public class AsyncTask {

    @SneakyThrows
    @Async
    public void doTask1() {
        long t1 = System.currentTimeMillis();
        Thread.sleep(2000);
        long t2 = System.currentTimeMillis();
        log.info("task1 cost {} ms" , t2-t1);
    }

    @SneakyThrows
    @Async
    public void doTask2() {
        long t1 = System.currentTimeMillis();
        Thread.sleep(3000);
        long t2 = System.currentTimeMillis();
        log.info("task2 cost {} ms" , t2-t1);
    }
}

@RestController
@RequestMapping("/async")
@Slf4j
public class AsyncController {
    @Autowired
    private AsyncTask asyncTask;

    @RequestMapping("/task")
    public void task() throws InterruptedException {
        long t1 = System.currentTimeMillis();
        asyncTask.doTask1();
        asyncTask.doTask2();
        Thread.sleep(1000);
        long t2 = System.currentTimeMillis();
        log.info("main cost {} ms", t2-t1);
    }
}

public void execute(Runnable task, long startTimeout) {
  Assert.notNull(task, "Runnable must not be null");
  Runnable taskToUse = this.taskDecorator != null ? this.taskDecorator.decorate(task) : task;
  //判斷是否開(kāi)啟限流，默認(rèn)為否
  if (this.isThrottleActive() && startTimeout > 0L) {
    //執(zhí)行前置操作，進(jìn)行限流
    this.concurrencyThrottle.beforeAccess();
    this.doExecute(new SimpleAsyncTaskExecutor.ConcurrencyThrottlingRunnable(taskToUse));
  } else {
    //未限流的情況，執(zhí)行線程任務(wù)
    this.doExecute(taskToUse);
  }

}

protected void doExecute(Runnable task) {
  //不斷創(chuàng)建線程
  Thread thread = this.threadFactory != null ? this.threadFactory.newThread(task) : this.createThread(task);
  thread.start();
}

//創(chuàng)建線程
public Thread createThread(Runnable runnable) {
  //指定線程名，task-1，task-2...
  Thread thread = new Thread(this.getThreadGroup(), runnable, this.nextThreadName());
  thread.setPriority(this.getThreadPriority());
  thread.setDaemon(this.isDaemon());
  return thread;
}

@Configuration
@EnableAsync
public class SyncConfiguration {
    @Bean(name = "asyncPoolTaskExecutor")
    public ThreadPoolTaskExecutor executor() {
        ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
        //核心線程數(shù)
        taskExecutor.setCorePoolSize(10);
        //線程池維護(hù)線程的最大數(shù)量,只有在緩沖隊(duì)列滿了之后才會(huì)申請(qǐng)超過(guò)核心線程數(shù)的線程
        taskExecutor.setMaxPoolSize(100);
        //緩存隊(duì)列
        taskExecutor.setQueueCapacity(50);
        //許的空閑時(shí)間,當(dāng)超過(guò)了核心線程出之外的線程在空閑時(shí)間到達(dá)之后會(huì)被銷毀
        taskExecutor.setKeepAliveSeconds(200);
        //異步方法內(nèi)部線程名稱
        taskExecutor.setThreadNamePrefix("async-");
        /**
         * 當(dāng)線程池的任務(wù)緩存隊(duì)列已滿并且線程池中的線程數(shù)目達(dá)到maximumPoolSize，如果還有任務(wù)到來(lái)就會(huì)采取任務(wù)拒絕策略
         * 通常有以下四種策略：
         * ThreadPoolExecutor.AbortPolicy:丟棄任務(wù)并拋出RejectedExecutionException異常。
         * ThreadPoolExecutor.DiscardPolicy：也是丟棄任務(wù)，但是不拋出異常。
         * ThreadPoolExecutor.DiscardOldestPolicy：丟棄隊(duì)列最前面的任務(wù)，然后重新嘗試執(zhí)行任務(wù)（重復(fù)此過(guò)程）
         * ThreadPoolExecutor.CallerRunsPolicy：重試添加當(dāng)前的任務(wù)，自動(dòng)重復(fù)調(diào)用 execute() 方法，直到成功
         */
        taskExecutor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        taskExecutor.initialize();
        return taskExecutor;
    }
}

@SneakyThrows
@Async("asyncPoolTaskExecutor")
public void doTask1() {
  long t1 = System.currentTimeMillis();
  Thread.sleep(2000);
  long t2 = System.currentTimeMillis();
  log.info("task1 cost {} ms" , t2-t1);
}

@Configuration
@EnableAsync
@Slf4j
public class AsyncConfiguration implements AsyncConfigurer {

    @Bean(name = "asyncPoolTaskExecutor")
    public ThreadPoolTaskExecutor executor() {
        ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
        //核心線程數(shù)
        taskExecutor.setCorePoolSize(2);
        //線程池維護(hù)線程的最大數(shù)量,只有在緩沖隊(duì)列滿了之后才會(huì)申請(qǐng)超過(guò)核心線程數(shù)的線程
        taskExecutor.setMaxPoolSize(10);
        //緩存隊(duì)列
        taskExecutor.setQueueCapacity(50);
        //許的空閑時(shí)間,當(dāng)超過(guò)了核心線程出之外的線程在空閑時(shí)間到達(dá)之后會(huì)被銷毀
        taskExecutor.setKeepAliveSeconds(200);
        //異步方法內(nèi)部線程名稱
        taskExecutor.setThreadNamePrefix("async-");
        /**
         * 當(dāng)線程池的任務(wù)緩存隊(duì)列已滿并且線程池中的線程數(shù)目達(dá)到maximumPoolSize，如果還有任務(wù)到來(lái)就會(huì)采取任務(wù)拒絕策略
         * 通常有以下四種策略：
         * ThreadPoolExecutor.AbortPolicy:丟棄任務(wù)并拋出RejectedExecutionException異常。
         * ThreadPoolExecutor.DiscardPolicy：也是丟棄任務(wù)，但是不拋出異常。
         * ThreadPoolExecutor.DiscardOldestPolicy：丟棄隊(duì)列最前面的任務(wù)，然后重新嘗試執(zhí)行任務(wù)（重復(fù)此過(guò)程）
         * ThreadPoolExecutor.CallerRunsPolicy：重試添加當(dāng)前的任務(wù)，自動(dòng)重復(fù)調(diào)用 execute() 方法，直到成功
         */
        taskExecutor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        taskExecutor.initialize();
        return taskExecutor;
    }

    /**
     * 指定默認(rèn)線程池
     */
    @Override
    public Executor getAsyncExecutor() {
        return executor();
    }

    @Override
    public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
        return (ex, method, params) ->
            log.error("線程池執(zhí)行任務(wù)發(fā)送未知錯(cuò)誤,執(zhí)行方法：{}",method.getName(),ex);
    }
}

@Async
public void doTask1() {
  long t1 = System.currentTimeMillis();
  Thread.sleep(2000);
  long t2 = System.currentTimeMillis();
  log.info("task1 cost {} ms" , t2-t1);
}

@SneakyThrows
@Async("otherTaskExecutor")
public void doTask2() {
  long t1 = System.currentTimeMillis();
  Thread.sleep(3000);
  long t2 = System.currentTimeMillis();
  log.info("task2 cost {} ms" , t2-t1);
}