Spring高级 事件监听器 （一）

事件监听器的两种方式

1. 实现 ApplicationListener 接口

• 根据接口泛型确定事件类型

2. @EventListener 标注监听方法

• 根据监听器方法参数确定事件类型
• 解析时机：在 SmartInitializingSingleton（所有单例初始化完成后），解析每个单例 bean

一、 实现 ApplicationListener 接口 作为监听器 （根据接口泛型确定事件类型）

1、事件发布器

package com.mangoubiubiu.event;

import org.springframework.context.ApplicationEvent;

public class MyEvent extends ApplicationEvent {
    public MyEvent(Object source) {
        super(source);
    }
}

2、事件监听器

package com.mangoubiubiu.event.listener;

import com.mangoubiubiu.event.MyEvent;
import lombok.extern.slf4j.Slf4j;
import org.springframework.context.ApplicationListener;
import org.springframework.stereotype.Component;

@Slf4j
@Component
public class EmailListener implements ApplicationListener<MyEvent> {
    @Override
    public void onApplicationEvent(MyEvent event) {
        log.info("发送邮件");
    }
}

package com.mangoubiubiu.event.listener;

import com.mangoubiubiu.event.MyEvent;
import lombok.extern.slf4j.Slf4j;
import org.springframework.context.ApplicationListener;
import org.springframework.stereotype.Component;

@Component
@Slf4j
public class SmsListener implements ApplicationListener<MyEvent> {
    @Override
    public void onApplicationEvent(MyEvent event) {
        log.info("发送短信");
    }
}

3、发布事件（注意：一个事件可以被多个监听器监听）

package com.mangoubiubiu.controller;

import com.mangoubiubiu.event.MyEvent;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiImplicitParam;
import io.swagger.annotations.ApiOperation;
import lombok.RequiredArgsConstructor;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import java.util.HashMap;

@Api(tags = "首页模块")
@RestController
@RequiredArgsConstructor
public class UserController {

    final ApplicationEventPublisher publisher;

    @ApiImplicitParam(name = "name",value = "姓名",required = true)
    @ApiOperation(value = "向客人问好")
    @GetMapping("/sayHi")
    public ResponseEntity<String> sayHi(@RequestParam(value = "name")String name){

        publisher.publishEvent(new MyEvent("UserController.sayHi"));

        return ResponseEntity.ok("Hi:" + name);
    }
}

二、@EventListener 标注监听方法

• 根据监听器方法参数确定事件类型
• 解析时机：在 SmartInitializingSingleton（所有单例初始化完成后），解析每个单例 bean

2、事件监听器

package com.mangoubiubiu.show.event.listener;

import com.mangoubiubiu.show.event.MyEvent;
import lombok.extern.slf4j.Slf4j;
import org.springframework.context.ApplicationListener;
import org.springframework.stereotype.Component;

@Slf4j
@Component
public class EmailListener implements ApplicationListener<MyEvent> {
    @Override
    public void onApplicationEvent(MyEvent event) {
        log.info("发送邮件");
    }
}

package com.mangoubiubiu.show.event.listener;

import com.mangoubiubiu.show.event.MyEvent;
import lombok.extern.slf4j.Slf4j;
import org.springframework.context.ApplicationListener;
import org.springframework.stereotype.Component;

@Component
@Slf4j
public class SmsListener implements ApplicationListener<MyEvent> {
    @Override
    public void onApplicationEvent(MyEvent event) {
        log.info("发送短信");
    }
}

3、发布事件 后测试