SpringBoot (九) @Async实现异步调用

前言

异步线程可能会非常小号cpu资源，大项目推荐使用mq异步实现。

1 App.java

@SpringBootApplication
@EnableAsync        // 开启异步注解
public class App {
    
    
    public static void main(String[] args) {
    
    
        SpringApplication.run(App.class, args);
    }
}

2 Controller

/*
 * @Author  : 有勇气的牛排（全网同名）
 * @FileName: CsAsync.java
 * desc     :
 * */

package com.couragesteak.controller;

import com.couragesteak.service.MemberServiceAsync;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@Slf4j
public class CsAsync {
    
    

    @Autowired
    private MemberServiceAsync memberServiceAsync;

    // http://127.0.0.1:8080/a_register
    @RequestMapping("/a_register")
    public String A_Register() {
    
    

        log.info(">>> 01");

        memberServiceAsync.smsAsync();

        log.info(">>> 03");
        return "注册成功";
    }
}

3 service

/*
 * @Author  : 有勇气的牛排（全网同名）
 * @FileName: MemberServiceAsync.java
 * desc     :
 * */

package com.couragesteak.service;

import lombok.extern.slf4j.Slf4j;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Component;

@Component
@Slf4j
public class MemberServiceAsync {
    
    
    @Async("taskExecutor")  // 指定线程池
    public String smsAsync() {
    
    
        log.info(">>> 2");

        try {
    
    
            log.info("正在发送中");
            Thread.sleep(3000);
        } catch (Exception e) {
    
    

        }

        return "恭喜注册成功";
    }
}

4 多线程池封装

/*
 * @Author  : 有勇气的牛排（全网同名）
 * @FileName: ThreadPoolConfig.java
 * desc     : 线程池配置
 * */

package com.couragesteak.config;

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

import java.util.concurrent.ThreadPoolExecutor;

@Configuration
@EnableAsync
public class ThreadPoolConfig {
    
    

    /**
     * 每秒需要多少个线程处理?
     * tasks/(1/taskcost)
     */
    private int corePoolSize = 3;

    /**
     * 线程池维护线程的最大数量
     * (max(tasks)- queueCapacity)/(1/taskcost)
     */
    private int maxPoolSize = 3;

    /**
     * 缓存队列
     * (coreSizePool/taskcost)*responsetime
     */
    private int queueCapacity = 10;

    /**
     * 允许的空闲时间
     * 默认为60
     */
    private int keepAlive = 100;

    @Bean
    public TaskExecutor taskExecutor() {
    
    
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        // 设置核心线程数
        executor.setCorePoolSize(corePoolSize);
        // 设置最大线程数
        executor.setMaxPoolSize(maxPoolSize);
        // 设置队列容量
        executor.setQueueCapacity(queueCapacity);
        // 设置允许的空闲时间（秒）
        //executor.setKeepAliveSeconds(keepAlive);
        // 设置默认线程名称
        executor.setThreadNamePrefix("thread-");
        // 设置拒绝策略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());
        // 等待所有任务结束后再关闭线程池
        executor.setWaitForTasksToCompleteOnShutdown(true);
        return executor;
    }
}