google中guava类库:AsyncEventBus

1.guava事件总线(AsyncEventBus)使用

1.1引入依赖

    <dependency>

      <groupId>com.google.guava</groupId>

      <artifactId>guava</artifactId>

      <version>23.0</version>

    </dependency>

1.2在spring中通过配置类(支持spring4.x以上及springboot)使AsyncEventBus交给spring容器管理,并设置为单例模式

package com.zy.eventbus;

import com.google.common.eventbus.AsyncEventBus;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Scope;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;

/**
 * 事件注入中心
 */
@Configuration
public class AsynEventBusConfig {

    @Bean
    @Scope("singleton")
    public AsyncEventBus asyncEventBus() {
        final ThreadPoolTaskExecutor executor = executor();
        return new AsyncEventBus(executor);
    }

    @Bean
    public ThreadPoolTaskExecutor executor(){
        /*
        org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor
        private int corePoolSize = 1;
        private int maxPoolSize = 2147483647;
        private int queueCapacity = 2147483647;
        private int keepAliveSeconds = 60;
        private boolean allowCoreThreadTimeOut = false;
        * */
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(5);
        executor.setMaxPoolSize(100);
        executor.setQueueCapacity(1000);
        // executor.setKeepAliveSeconds(600);
        // executor.setAllowCoreThreadTimeOut(true);
        return executor;
    }
}

1.3在需要异步执行的类中注册该类,并给异步执行的方法上加@Subscribe注解

package com.zy.service.impl;

import com.google.common.eventbus.AllowConcurrentEvents;

import com.google.common.eventbus.AsyncEventBus;

import com.google.common.eventbus.Subscribe;import com.zy.service.StuServiceI;

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

import org.springframework.stereotype.Service;

import javax.annotation.PostConstruct;

@Service("stuService")

public class StuServiceImpl implements StuServiceI {

    @Autowired

    private AsyncEventBus asyncEventBus;

    @PostConstruct // 注册该类

    public void register(){

        asyncEventBus.register(this);

    }

    @AllowConcurrentEvents//线程安全

    @Subscribe // 异步执行的方法标识:需要传入String类型参数

    public void async01(String str){

        System.out.println(str);

    }

}

1.4调用方法的类

package com.zy.controller;

import com.google.common.eventbus.AsyncEventBus;

import com.zy.service.StuServiceI;

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

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

@RestController

@RequestMapping

public class GuavaEventBusController {

    @Autowired

    private AsyncEventBus eventBus;

    @GetMapping("/eventbus")

    public String eventbus(){

        System.out.println("hello");

        eventBus.post("bbb"); // 调用执行方法的参数

        System.out.println("world");

        return "hello eventbus";

    }

}