spring的事件应用

理论

在分布式场景下,实现同步转异步的方式有三种方式:

1.异步线程池执行;比如借助@Asyn注解,放到spring自带的线程池中去执行;

2.放到消息队列中,在消费者的代码中异步的消费,执行相关的逻辑;

3.基于spring的事件机制,触发事件,在监听器里实现相关逻辑;

spring中自带了事件的支持,核心类是ApplicationEventPublisher;

事件包括三个要点:下面是一个demo的实现,理论结合实战。

1 事件的定义;

package com.springbootpractice.demoevent.event;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.ApplicationEvent;

/**
 * @说明 吃饭事件
 * @作者 carter
 * @创建时间 2019年07月12日 13:12
 **/
public class EatEvent extends ApplicationEvent {

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

    private Boolean eatFinished;

    public EatEvent(Boolean eatFinished) {
        super(eatFinished);
        this.eatFinished = eatFinished;
    }

    public void callGirlFriend() {
        logger.info("美女,吃完饭了,来收拾一下吧!");
    }

    public void callBrothers() {
        logger.info("兄弟们,吃完饭了,来打dota !");
    }

    public Boolean getEatFinished() {
        return eatFinished;
    }
}

2 事件监听的定义;

package com.springbootpractice.demoevent.event.listener;

import com.springbootpractice.demoevent.event.EatEvent;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.ApplicationListener;
import org.springframework.stereotype.Component;

import java.util.Objects;

/**
 * 说明: XEvent的事件监听器
 *
 * @author carter
 * 创建时间 2019年07月12日 13:19
 **/
@Component
public class EatEventListener implements ApplicationListener<EatEvent> {

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

    @Override
    public void onApplicationEvent(EatEvent xEvent) {
        if (Objects.isNull(xEvent)) {
            return;
        }

        if (xEvent.getEatFinished()) {
            xEvent.callGirlFriend();
            logger.info("xxxx,女朋友拒绝收拾!");
            xEvent.callBrothers();
            logger.info("满人了,下次带你!");
        }

    }
}

3 发布事件;

package com.springbootpractice.demoevent.web;

import com.springbootpractice.demoevent.event.EatEvent;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * 说明 测试控制器
 *
 * @author carter
 * 创建时间 2019年07月12日 13:23
 **/
@RestController
public class TestController {

    private final ApplicationEventPublisher applicationEventPublisher;

    @Autowired
    public TestController(ApplicationEventPublisher applicationEventPublisher) {
        this.applicationEventPublisher = applicationEventPublisher;
    }

    @GetMapping(path = "/eatOver")
    public Object eatOver() {
        EatEvent xEvent = new EatEvent(true);
        applicationEventPublisher.publishEvent(xEvent);
        return "eat over and publish event success";
    }

}

无需多余的配置,springmvc直接支持的;

实战

完整代码地址

    原文作者:李福春
    原文地址: https://segmentfault.com/a/1190000020081945
    本文转自网络文章,转载此文章仅为分享知识,如有侵权,请联系博主进行删除。
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