google中guava類庫:AsyncEventBus

1.guava事件總線(AsyncEventBus)使用

1.1引入依賴

    <dependency>
      <groupId>com.google.guava</groupId>
      <artifactId>guava</artifactId>
      <version>23.0</version>
    </dependency>

1.2在spring中經過配置類(支持spring4.x以上及springboot)使AsyncEventBus交給spring容器管理,並設置爲單例模式

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在須要異步執行的類中註冊該類,並給異步執行的方法上加@Subscribe註解

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 // 註冊該類
    public void register(){
        asyncEventBus.register(this);
    }

    @AllowConcurrentEvents//線程安全
    @Subscribe // 異步執行的方法標識:須要傳入String類型參數
    public void async01(String str){
        System.out.println(str);
    }
}

1.4調用方法的類

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"); // 調用執行方法的參數
        System.out.println("world");
        return "hello eventbus";
    }
}