spring的事件機制實戰
阿新 • • 發佈:2019-12-31
理論
在分散式場景下,實現同步轉非同步的方式有三種方式:
1.非同步執行緒池執行;比如藉助@Asyn註解,放到spring自帶的執行緒池中去執行;
2.放到訊息佇列中,在消費者的程式碼中非同步的消費,執行相關的邏輯;
3.基於spring的事件機制,觸發事件,在監聽器裡實現相關邏輯;
spring中自帶了事件的支援,核心類是ApplicationEventPublisher;
事件包括三個要點:下面是一個demo的實現,理論結合實戰。
1 事件的定義;
package com.springbootpractice.demoevent.event;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.ApplicationEvent;
/**
* @說明 吃飯事件
* @作者 carter
* @建立時間 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,吃完飯了,來收拾一下吧!");
}
public void callBrothers() {
logger.info("兄弟們,吃完飯了,來打dota !");
}
public Boolean getEatFinished() {
return eatFinished;
}
}複製程式碼
2 事件監聽的定義;
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;
/**
* 說明: XEvent的事件監聽器
*
* @author carter
* 建立時間 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,女朋友拒絕收拾!");
xEvent.callBrothers();
logger.info("滿人了,下次帶你!");
}
}
}複製程式碼
3 釋出事件;
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;
/**
* 說明 測試控制器
*
* @author carter
* 建立時間 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";
}
}複製程式碼
無需多餘的配置,springmvc直接支援的;