spring @Async 线程池使用

最近公司项目正逐渐从dubbo向springCloud转型，在本次新开发的需求中，全部使用springcloud进行，在使用时线程池，考虑使用spring封装的线程池，现将本次使用心得及内容记录下来

一、线程池常规使用方式

之前使用线程池的方式，都是自己定义线程池，然后写多线程类，用线程池去调用，如下：

package cn.leadeon.message.client;

import cn.leadeon.comm.log.Log;
import cn.leadeon.message.req.MessageProducerReq;
import lombok.Data;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * 流量消息发送类，线程池调用
 *
 * @author LiJunJun
 * @since 2018/9/30
 */
@Data
public class MessageClientSendMsg {

    /**
     * 日志记录器
     */
    private static final Log LOGGER = new Log(MessageClientSendMsg.class);

    /**
     * 线程池
     */
    private static ExecutorService threadPool;

    /**
     * trace
     */
    private String trace;

    /**
     * 手机号
     */
    private String cellNum;

    /**
     * 消息实体
     */
    private MessageProducerReq messageProducerReq;

    static {
        threadPool = Executors.newFixedThreadPool(10);
    }

    /**
     * 构造函数
     *
     * @param trace 请求流水
     * @param cellNum 电话号码
     * @param messageProducerReq 消息实体
     */
    public MessageClientSendMsg(String trace, String cellNum, MessageProducerReq messageProducerReq) {

        this.trace = trace;
        this.cellNum = cellNum;
        this.messageProducerReq = messageProducerReq;
    }

    /**
     * 消息发送
     */
    public void sendMsg() {

        SendMsgRunable sendMsgRunable = new SendMsgRunable();

        threadPool.execute(sendMsgRunable);
    }

    /**
     * 发送消息内部类并处理异常，不能影响主线程的业务
     */
    class SendMsgRunable implements Runnable {

        @Override
        public void run() {

            try {
                MessageClientProducer msgClintProducer = new MessageClientProducer();
                msgClintProducer.sendAsyncWithPartition(trace, cellNum, messageProducerReq);
            } catch (Exception e) {
                LOGGER.error("消息发送失败!，trace：" + trace);
            }
        }
    }
}

二、使用spring的线程池

• 线程池的启用

　　有两种方式，配置文件或者注解

　　注解：使用@EnableAsync标注启用spring线程池，@Async将方法标注为异步方法，spring扫描到后，执行该方法时，会另起新线程去执行，非常简单

package cn.leadeon.message.test;

import org.springframework.scheduling.annotation.Async;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.stereotype.Component;

/**
 * @author LiJunJun
 * @since 2018/10/11
 */
@Component
@EnableAsync
public class AsyncTest {

    @Async
    public void test1() {

        System.out.println("异步执行test1！！！");
        System.out.println("线程id：" + Thread.currentThread().getId());
        System.out.println("线程名称：" + Thread.currentThread().getName());

    }

    @Async
    public void test2() {

        System.out.println("异步执行test2！！！");
        System.out.println("线程id：" + Thread.currentThread().getId());
        System.out.println("线程名称：" + Thread.currentThread().getName());
    }

    @Async
    public void test3() {

        System.out.println("异步执行test3！！！");
        System.out.println("线程id：" + Thread.currentThread().getId());
        System.out.println("线程名称：" + Thread.currentThread().getName());
    }
}

配置文件：新增spring的配置文件spring-threadpool.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx" xmlns:jdbc="http://www.springframework.org/schema/jdbc"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:task="http://www.springframework.org/schema/task"
       xsi:schemaLocation="http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd
     http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
     http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.1.xsd
     http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
     http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task.xsd"
       default-autowire="byName">

    <description>流量消息spring线程池配置</description>

    <!-- 缺省的异步任务线程池 -->
    <task:annotation-driven executor="messageExecutor"/>
    <task:executor id="asyncExecutor" pool-size="100-10000" queue-capacity="10"/>

    <!-- 处理message的线程池 -->
    <task:executor id="messageExecutor" pool-size="15-50" queue-capacity="100" keep-alive="60"
                   rejection-policy="CALLER_RUNS"/>

</beans>

使用注解引入配置文件或者在自己的spring配置文件中import即可

package cn.leadeon.message.test;

import org.springframework.context.annotation.ImportResource;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Component;

/**
 * @author LiJunJun
 * @since 2018/10/11
 */
@Component
@ImportResource("classpath:/config/spring-threadpool.xml")
public class AsyncTest {

    @Async
    public void test1() {

        System.out.println("异步执行test1！！！");
        System.out.println("线程id：" + Thread.currentThread().getId());
        System.out.println("线程名称：" + Thread.currentThread().getName());

    }

    @Async
    public void test2() {

        System.out.println("异步执行test2！！！");
        System.out.println("线程id：" + Thread.currentThread().getId());
        System.out.println("线程名称：" + Thread.currentThread().getName());
    }

    @Async
    public void test3() {

        System.out.println("异步执行test3！！！");
        System.out.println("线程id：" + Thread.currentThread().getId());
        System.out.println("线程名称：" + Thread.currentThread().getName());
    }
}

　　配置文件可以自己配置线程池的相关参数，自己可以配置多个线程池，使用时，用@Async(value="beanId")区分即可

　　注意点：
　　@EnableAsync注解与<task:annotation-driven executor="messageExecutor"/>等价，两者只能使用其一，不然启动会报错

• java编程方式配置自定义线程池，如下：

package cn.leadeon.message.base.threadpool;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;

import java.util.concurrent.Executor;
import java.util.concurrent.ThreadPoolExecutor;

/**
 * 流量消息线程池配置
 *
 * @author LiJunJun
 * @since 2018/10/10
 */
@Configuration
public class ThreadPoolConfiguration {

    /**
     * 核心线程数：线程池创建时候初始化的线程数
     */
    @Value("${executor.core.pool.size}")
    private int corePoolSize;

    /**
     * 最大线程数：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
     */
    @Value("${executor.max.pool.size}")
    private int maxPoolSize;

    /**
     * 缓冲队列200：用来缓冲执行任务的队列
     */
    @Value("${executor.queue.capacity}")
    private int queueCapacity;

    /**
     * 允许线程的空闲时间(单位：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
     */
    @Value("${executor.keepalive.Seconds}")
    private int keepAliveSeconds;

    /**
     * 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
     */
    @Value("${executor.thread.name.prefix}")
    private String threadNamePrefix;

    @Bean
    public Executor MessageExecutor() {

        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(corePoolSize);
        executor.setMaxPoolSize(maxPoolSize);
        executor.setQueueCapacity(queueCapacity);
        executor.setKeepAliveSeconds(keepAliveSeconds);
        executor.setThreadNamePrefix(threadNamePrefix);

        // 线程池对拒绝任务的处理策略：这里采用了CallerRunsPolicy策略，当线程池没有处理能力的时候，该策略会直接在 execute 方法的调用线程中运行被拒绝的任务；如果执行程序已关闭，则会丢弃该任务
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        executor.initialize();
        return executor;
    }
}

• 测试

package cn.leadeon.message.test;

import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;

/**
 * spring线程池单元测试
 *
 * @author LiJunJun
 * @since 2018/10/11
 */
public class TestSpringThreadPool extends JunitTestBase {

    @Autowired
    private AsyncTest asyncTest;

    /**
     * spring线程池单元测试
     */
    @Test
    public void testThreadPool() {

        System.out.println("主线程id：" + Thread.currentThread().getId());
        System.out.println("主线程名称：" + Thread.currentThread().getName());
        asyncTest.test1();
        asyncTest.test2();
        asyncTest.test3();

    }
}

测试结果：主线程和异步方法分别使用了不同的线程去调用，测试完成