java多线程（ThreadPoolTaskExecutor 线程池处理）

一、定义一个公用线程池，统一处理多线程

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;

import java.util.concurrent.Executor;

@Configuration
@EnableAsync  // 启用异步任务
public class AsyncConfiguration {

    // 声明一个线程池(并指定线程池的名字)
    @Bean("taskExecutor")
    public Executor asyncExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        //核心线程数5：线程池创建时候初始化的线程数
        executor.setCorePoolSize(5);
        //最大线程数5：线程池最大的线程数，只有在缓冲队列满了之后才会申请超过核心线程数的线程
        executor.setMaxPoolSize(5);
        //缓冲队列500：用来缓冲执行任务的队列
        executor.setQueueCapacity(500);
        //允许线程的空闲时间60秒：当超过了核心线程出之外的线程在空闲时间到达之后会被销毁
        executor.setKeepAliveSeconds(60);
        //线程池名的前缀：设置好了之后可以方便我们定位处理任务所在的线程池
        executor.setThreadNamePrefix("DailyAsync-");
        executor.initialize();
        return executor;
    }
}

二、多线程任务实现及调用

import com.base.api.AsyncTaskService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CompletableFuture;

@Service
public class AsyncTaskServiceImpl implements AsyncTaskService {

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

       // 这里进行标注为异步任务，在执行此方法的时候，会单独开启线程来执行(并指定线程池的名字)
    @Async("taskExecutor")
    public CompletableFuture> GetListTask1() throws InterruptedException {
        logger.info("GetListTask1");

        List list = new ArrayList();

        for (int i = 0; i< 10; i++)
        {
            list.add("Task1_" + String.valueOf(i));
        }

        Thread.sleep(3 * 1000);

        return CompletableFuture.completedFuture(list);
    }


    // 这里进行标注为异步任务，在执行此方法的时候，会单独开启线程来执行(并指定线程池的名字)
    @Async("taskExecutor")
    public CompletableFuture> GetListTask2() throws InterruptedException {
        logger.info("GetListTask1");

        List list = new ArrayList();

        for (int i = 0; i< 10; i++)
        {
            list.add("Task2_" + String.valueOf(i));
        }

        Thread.sleep(5 * 1000);

        return CompletableFuture.completedFuture(list);
    }


    // 这里进行标注为异步任务，在执行此方法的时候，会单独开启线程来执行(并指定线程池的名字)
    @Async("taskExecutor")
    public CompletableFuture> GetListTask3() throws InterruptedException {
        logger.info("GetListTask1");

        List list = new ArrayList();

        for (int i = 0; i< 10; i++)
        {
            list.add("Task3_" + String.valueOf(i));
        }

        Thread.sleep(1000);

        return CompletableFuture.completedFuture(list);
    }

    //多线程
    public List TestAsyncTask()
    {
        try {

            long start = System.currentTimeMillis();

            // Kick of multiple, asynchronous lookups
            CompletableFuture> task1 = GetListTask1();
            CompletableFuture> task2 = GetListTask2();
            CompletableFuture> task3 = GetListTask3();

            // Wait until they are all done
            //join() 的作用：让“主线程”等待“子线程”结束之后才能继续运行
            CompletableFuture.allOf(task1,task2,task3).join();

            // Print results, including elapsed time
            float exc = (float)(System.currentTimeMillis() - start)/1000;

            logger.error("TestAsyncTask Elapsed time: " + exc + " seconds");

            List list1 = task1.get();
            List list2 = task2.get();
            List list3 = task3.get();

            list1.addAll(list2);
            list1.addAll(list3);
            return list1;

        } catch (Exception e) {
            logger.error("TestAsyncTask失败",e);
        }
        finally {

        }
        return null;
    }
}