監聽ApplicationListener和ApplicationEvent簡單使用

本來想實現一個功能就是，在登入成功之後，將一些使用者的資訊，放入到session裡面，本來想，在登入介面成功回撥之後，在寫，但是想做一個監聽的動作，監聽著登入成功的介面，之後走到監聽函式裡面，進行業務處理。

1、首先寫一個監聽類，之後實現ApplicationListener介面，實現其中的public void onApplicationEvent(ApplicationEvent event)方法，其實ApplicationListener介面可以使用泛型，但是我為了防止以後還有監聽，所以我沒有寫泛型，而是在onApplicationEvent

package cn.springboot.yzpt.listener;

import cn.springboot.yzpt.common.SuccessfulAuthenticationEvent;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationListener;

public class SuccessLoginListener implements ApplicationListener {

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

    @Override
    public void onApplicationEvent(ApplicationEvent event) {
        if(event instanceof SuccessfulAuthenticationEvent){

            SuccessfulAuthenticationEvent successfulAuthenticationEvent = (SuccessfulAuthenticationEvent)event;

            logger.info(successfulAuthenticationEvent.toString());
        }
    }

}
 

2、緊接著需要建立一個監聽事件，需要繼承ApplicationEvent這個類，這裡面所需要的屬性，自己去定義，我定義HttpServletRequest httpServletRequest; HttpServletResponse httpServletResponse; String sessionId，這三個屬性，用來滿足我的業務需求。

package cn.springboot.yzpt.common;

import org.springframework.context.ApplicationEvent;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;


public class SuccessfulAuthenticationEvent extends ApplicationEvent {

    private static final long serialVersionUID = 3039313222160544111L;

    private HttpServletRequest httpServletRequest;
    private HttpServletResponse httpServletResponse;
    private String sessionId;

    public SuccessfulAuthenticationEvent(Object source,HttpServletRequest httpServletRequest,HttpServletResponse httpServletResponse) {
        super(source);
        this.httpServletRequest = httpServletRequest;
        this.httpServletResponse = httpServletResponse;
    }


    public String getSessionId() {
        return sessionId;
    }

    public void setSessionId(String sessionId) {
        this.sessionId = sessionId;
    }

    public HttpServletResponse getHttpServletResponse() {
        return httpServletResponse;
    }

    public void setHttpServletResponse(HttpServletResponse httpServletResponse) {
        this.httpServletResponse = httpServletResponse;
    }

    public HttpServletRequest getHttpServletRequest() {
        return httpServletRequest;
    }

    public void setHttpServletRequest(HttpServletRequest httpServletRequest) {
        this.httpServletRequest = httpServletRequest;
    }
}
 

3、接著需要在springboot的啟動類裡面配置一下監聽。

package cn.springboot.yzpt;

import cn.springboot.yzpt.listener.SuccessLoginListener;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;

@SpringBootApplication
@MapperScan("cn.springboot.yzpt.mapper")
public class YzptApplication {

    public static void main(String[] args) {
        ConfigurableApplicationContext context = SpringApplication.run(YzptApplication.class, args);
        //裝載監聽
        context.addApplicationListener(new SuccessLoginListener());
    }
}

 4、這個時候需要設定一個觸發這個事件的方法。

package cn.springboot.yzpt.common;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@Component
public class EventPublisher {

    @Autowired
    private ApplicationContext applicationContext;

    public void pushlish(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse){
        applicationContext.publishEvent(new SuccessfulAuthenticationEvent(this,httpServletRequest,httpServletResponse));
    }
}

5、最後就是在自己的業務邏輯裡面呼叫這個觸發的方法了，在登入成功裡面寫這個觸發的事件，用來處理這個介面之後的業務邏輯。

package cn.springboot.yzpt.controller.loginUser;

import cn.springboot.yzpt.common.CodeEnums;
import cn.springboot.yzpt.common.EventPublisher;
import cn.springboot.yzpt.common.HttpRequestEntity;
import cn.springboot.yzpt.exception.YzptException;
import cn.springboot.yzpt.server.loginUser.LoginUserServer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.Map;

@RestController
@RequestMapping("/loginUser")
public class LoginUserController {

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

    @Autowired
    LoginUserServer loginUserServer;

    @Autowired
    EventPublisher eventPublisher;

    @RequestMapping(value = "/login", method = RequestMethod.POST)
    @ResponseBody
    public HttpRequestEntity login(@RequestBody Map<String, String> userInfo, HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) {
        HttpRequestEntity httpRequestEntity = new HttpRequestEntity();
        try {
            boolean loginType = loginUserServer.login(userInfo.get("user"), userInfo.get("password"));
            httpServletRequest.getSession().setAttribute("id", "12314434231");
            if (loginType) {
                httpRequestEntity.setMessage("登陸成功");


                eventPublisher.pushlish(httpServletRequest,httpServletResponse);

                logger.info(userInfo.get("user") + "登陸成功");
            }
        } catch (YzptException e) {
            httpRequestEntity.setCode(e.getCode());
            httpRequestEntity.setMessage(e.getErrMsg());
        } catch (Exception e) {
            logger.error("/loginUser/login：出現異常", e);
            httpRequestEntity.setCodeEnums(CodeEnums.SYSTEM_ERR);
        }
        return httpRequestEntity;
    }
}