SpringBoot------Servlet3.0的注解自定义原生Listener监听器

前言

常用监听器：
//contextListener可以监听数据库的连接，第三方组件的交互，还有静态文件加载等等
servletContextListener
HttpSessionListener
servletRequestListener

1.添加pom.xml相关依赖

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>top.ytheng</groupId>
  <artifactId>springboot-demo</artifactId>
  <version>0.0.1</version>
  <packaging>jar</packaging>
  
  <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional>
              <scope>true</scope>
        </dependency>
    </dependencies>

    <build>
        <!-- 打包的名称 -->
        <finalName>myspringboot</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

2.添加自定义ContextListener监听器

package top.ytheng.demo.listener;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;

/*
 * 上下文监听器
 * 
 * */
@WebListener
public class ContextListener implements ServletContextListener {

    @Override
    public void contextInitialized(ServletContextEvent sce) {
        // TODO Auto-generated method stub
        System.out.println("======contextInitialized======");
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        // TODO Auto-generated method stub
        System.out.println("======contextDestroyed======");
    }
    
}

3.添加自定义RequestListener

package top.ytheng.demo.listener;

import javax.servlet.ServletRequestEvent;
import javax.servlet.ServletRequestListener;
import javax.servlet.annotation.WebListener;

@WebListener
public class RequestListener implements ServletRequestListener{

    @Override
    public void requestDestroyed(ServletRequestEvent sre) {
        // TODO Auto-generated method stub
        System.out.println("======requestDestroyed======");
    }

    @Override
    public void requestInitialized(ServletRequestEvent sre) {
        // TODO Auto-generated method stub
        System.out.println("======requestInitialized======");
    }
    
}

4.添加测试控制器

package top.ytheng.demo.controller;

import java.util.HashMap;
import java.util.Map;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/api/v2/listener")
public class ListenerController {
    
    @GetMapping("/test")
    public Object testListener() {
        Map<String, Object> map = new HashMap<>();
        map.put("username", "theng");
        map.put("password", "123456");
        
        System.out.println("listenerController");
        return map;
    }
}

5.添加启动类

package top.ytheng.demo;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.boot.web.servlet.ServletComponentScan;

@SpringBootApplication //等于下面3个
//@SpringBootConfiguration
//@EnableAutoConfiguration
//@ComponentScan
//拦截器用到
@ServletComponentScan
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

}

6.右键项目Run As启动，访问地址

http://localhost:8080/api/v2/listener/test

另附：