第一步：首先配置線程基本參數(shù)

可以放在application.propertes文件種也可以放在自己新建的config/文件目錄下，注意：但是需要使用@PropertySource把配置文件進行加載。

# 異步線程配置
# 配置核心線程數(shù)
async.executor.thread.core_pool_size = 8
# 配置最大線程數(shù)
async.executor.thread.max_pool_size = 20
# 配置隊列大小
async.executor.thread.queue_capacity = 99999
# 配置線程池中的線程的名稱前綴
async.executor.thread.name.prefix = async-service-

第二步：讓Spring Boot加載

用來定義如何創(chuàng)建一個ThreadPoolTaskExecutor，要使用@Configuration和@EnableAsync這兩個注解，表示這是個配置類，并且是線程池的配置類

@Slf4j
@EnableAsync
@Configuration
public class RCExecutorConfig {
 
  @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() {
         log.info("start asyncServiceExecutor");
         ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
         //ThreadPoolTaskExecutor executor = new VisiableThreadPoolTaskExecutor();
         //配置核心線程數(shù)
         executor.setCorePoolSize(corePoolSize);
         //配置最大線程數(shù)
         executor.setMaxPoolSize(maxPoolSize);
         //配置隊列大小
         executor.setQueueCapacity(queueCapacity);
         //配置線程池中的線程的名稱前綴
         executor.setThreadNamePrefix(namePrefix);
 
         // rejection-policy：當pool已經(jīng)達到max size的時候，如何處理新任務(wù)
         // CALLER_RUNS：不在新線程中執(zhí)行任務(wù)，而是有調(diào)用者所在的線程來執(zhí)行
         executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
         //執(zhí)行初始化
         executor.initialize();
         return executor;
     }
}

第三步：創(chuàng)建一個service接口

是異步線程的接口，便于測試

public interface AsyncService {
 
 /**
     *  執(zhí)行異步任務(wù)
     *  可以根據(jù)需求，自己加參數(shù)擬定
     */
    void executeAsync();
}

第四步：編寫現(xiàn)實類

將Service層的服務(wù)異步化，在executeAsync()方法上增加注解@Async("asyncServiceExecutor")，asyncServiceExecutor方法是前面RCExecutorConfig.java中的方法名，表明executeAsync方法進入的線程池是asyncServiceExecutor方法創(chuàng)建的。

測試方面這里我加入了一個定時任務(wù)，使用的是corn表達式。（不懂得同學(xué)可以網(wǎng)上了解一下）

@Slf4j
@Service
public class AsyncServiceImpl implements AsyncService {
 
 @Override
 @Scheduled(cron = " */1 * * * * ? ")
 @Async("asyncServiceExecutor")
 public void executeAsync() {
  log.info("start executeAsync");
        System.out.println("異步線程執(zhí)行批量插入等耗時任務(wù)");
        log.info("end executeAsync");  
 }  
}

第五步：測試結(jié)果如下

10:32:15.004 [async-service-1] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:32:15.004 [async-service-1] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:32:16.003 [async-service-2] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:32:16.004 [async-service-2] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:32:17.001 [async-service-3] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:32:17.001 [async-service-3] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:32:18.002 [async-service-4] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:32:18.003 [async-service-4] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:32:19.002 [async-service-5] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:32:19.003 [async-service-5] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:32:20.001 [async-service-6] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:32:20.002 [async-service-6] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:32:21.002 [async-service-7] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:32:21.002 [async-service-7] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:32:22.004 [async-service-8] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:32:22.005 [async-service-8] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:32:23.001 [async-service-1] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:32:23.003 [async-service-1] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:32:24.003 [async-service-2] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:32:24.003 [async-service-2] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:32:25.001 [async-service-3] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:32:25.001 [async-service-3] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:32:26.002 [async-service-4] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:32:26.002 [async-service-4] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:32:27.002 [async-service-5] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:32:27.003 [async-service-5] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:32:28.001 [async-service-6] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:32:28.001 [async-service-6] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:32:29.001 [async-service-7] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:32:29.002 [async-service-7] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:32:30.001 [async-service-8] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:32:30.001 [async-service-8] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:32:31.001 [async-service-1] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:32:31.001 [async-service-1] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync

還沒完：

通過以上日志可以發(fā)現(xiàn)，[async-service-]是有多個線程的，顯然已經(jīng)在我們配置的線程池中執(zhí)行了，表明每次請求都快速響應(yīng)了，而耗時的操作都留給線程池中的線程去異步執(zhí)行；

還有另一個問提就是，雖然已經(jīng)用上了線程池，但是依然不清楚線程池當時的情況，有多少線程在執(zhí)行，多少在隊列中等待呢？于是這里我創(chuàng)建了一個ThreadPoolTaskExecutor的子類，可以把每次提交線程的時候都會將當前線程池的運行狀況打印出來

import lombok.extern.slf4j.Slf4j;
 
@Slf4j
public class VisiableThreadPoolTaskExecutor extends  ThreadPoolTaskExecutor {
 
    /**
  * 
  */
 private static final long serialVersionUID = -3518460523928455463L; 
 private void showThreadPoolInfo(String prefix) {
        ThreadPoolExecutor threadPoolExecutor = getThreadPoolExecutor(); 
        if (null == threadPoolExecutor) {
            return;
        }
 
        log.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);
    } 
}

其次：修改RCExecutorConfig.java的asyncServiceExecutor方法，

將ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor()改為ThreadPoolTaskExecutor executor = new VisiableThreadPoolTaskExecutor()

 @Bean(name = "asyncServiceExecutor")
     public Executor asyncServiceExecutor() {
         log.info("start asyncServiceExecutor");
         //ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
         ThreadPoolTaskExecutor executor = new VisiableThreadPoolTaskExecutor();
         //配置核心線程數(shù)
         executor.setCorePoolSize(corePoolSize);
         //配置最大線程數(shù)
         executor.setMaxPoolSize(maxPoolSize);
         //配置隊列大小
         executor.setQueueCapacity(queueCapacity);
         //配置線程池中的線程的名稱前綴
         executor.setThreadNamePrefix(namePrefix); 
         // rejection-policy：當pool已經(jīng)達到max size的時候，如何處理新任務(wù)
         // CALLER_RUNS：不在新線程中執(zhí)行任務(wù)，而是有調(diào)用者所在的線程來執(zhí)行
         executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
         //執(zhí)行初始化
         executor.initialize();
         return executor;
     }

測試結(jié)果如下：

異步線程執(zhí)行批量插入等耗時任務(wù)
10:41:35.003 [async-service-5] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:41:36.001 [sheduled-pool-1-thread-1] INFO c.a.a.e.t.VisiableThreadPoolTaskExecutor - async-service-, 2. do submit,taskCount [5], completedTaskCount [5], activeCount [0], queueSize [0]
10:41:36.001 [async-service-6] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:41:36.002 [async-service-6] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:41:37.001 [sheduled-pool-1-thread-7] INFO c.a.a.e.t.VisiableThreadPoolTaskExecutor - async-service-, 2. do submit,taskCount [6], completedTaskCount [6], activeCount [0], queueSize [0]
10:41:37.001 [async-service-7] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:41:37.002 [async-service-7] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:41:38.002 [sheduled-pool-1-thread-7] INFO c.a.a.e.t.VisiableThreadPoolTaskExecutor - async-service-, 2. do submit,taskCount [7], completedTaskCount [7], activeCount [0], queueSize [0]
10:41:38.002 [async-service-8] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:41:38.002 [async-service-8] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:41:39.001 [sheduled-pool-1-thread-7] INFO c.a.a.e.t.VisiableThreadPoolTaskExecutor - async-service-, 2. do submit,taskCount [8], completedTaskCount [8], activeCount [0], queueSize [0]
10:41:39.001 [async-service-1] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:41:39.002 [async-service-1] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:41:40.003 [sheduled-pool-1-thread-7] INFO c.a.a.e.t.VisiableThreadPoolTaskExecutor - async-service-, 2. do submit,taskCount [9], completedTaskCount [9], activeCount [0], queueSize [0]
10:41:40.003 [async-service-2] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:41:40.003 [async-service-2] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:41:41.001 [sheduled-pool-1-thread-7] INFO c.a.a.e.t.VisiableThreadPoolTaskExecutor - async-service-, 2. do submit,taskCount [10], completedTaskCount [10], activeCount [0], queueSize [0]
10:41:41.001 [async-service-3] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:41:41.001 [async-service-3] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:41:42.000 [sheduled-pool-1-thread-7] INFO c.a.a.e.t.VisiableThreadPoolTaskExecutor - async-service-, 2. do submit,taskCount [11], completedTaskCount [11], activeCount [0], queueSize [0]
10:41:42.000 [async-service-4] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:41:42.000 [async-service-4] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:41:43.001 [sheduled-pool-1-thread-7] INFO c.a.a.e.t.VisiableThreadPoolTaskExecutor - async-service-, 2. do submit,taskCount [12], completedTaskCount [12], activeCount [0], queueSize [0]
10:41:43.002 [async-service-5] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:41:43.003 [async-service-5] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:41:44.001 [sheduled-pool-1-thread-7] INFO c.a.a.e.t.VisiableThreadPoolTaskExecutor - async-service-, 2. do submit,taskCount [13], completedTaskCount [13], activeCount [0], queueSize [0]
10:41:44.001 [async-service-6] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync
異步線程執(zhí)行批量插入等耗時任務(wù)
10:41:44.001 [async-service-6] INFO c.a.a.service.impl.AsyncServiceImpl - end executeAsync
10:41:45.000 [sheduled-pool-1-thread-7] INFO c.a.a.e.t.VisiableThreadPoolTaskExecutor - async-service-, 2. do submit,taskCount [14], completedTaskCount [14], activeCount [0], queueSize [0]
10:41:45.001 [async-service-7] INFO c.a.a.service.impl.AsyncServiceImpl - start executeAsync

解釋：這里意思提交了14個任務(wù)，處理了14個任務(wù)，對列中還剩0個任務(wù)

10:41:45.000 [sheduled-pool-1-thread-7] INFO c.a.a.e.t.VisiableThreadPoolTaskExecutor - async-service-, 2. do submit,taskCount [14], completedTaskCount [14], activeCount [0], queueSize [0]

到此為止就OK了！

以上為個人經(jīng)驗，希望能給大家一個參考，也希望大家多多支持腳本之家。