springboot实战笔记(七 )----springboot整合Listener

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一 前言

  在以往的web.xml方式中，我们是通过以下形式进行配置Listener的：

<listener>
 	<listener-class>com.bjsxt.listener.FirstListener</listener-class>
</listener>

但是在springboot整合Listener可以通过以下的两种方式，

•  通过注解扫描完成 Listener  组件的注册
•  通过方法完成 Listener  组件的注册

pom.xml：

<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>
  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.10.RELEASE</version>
  </parent>
  <groupId>com.bjsxt</groupId>
  <artifactId>04-spring-boot-Listener</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  
  <!-- jdk1.7 -->
  <properties>
  	<java.version>1.7</java.version>
  </properties>
  
  <dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
</dependencies>
</project>

二 注解扫描方式

1.编写 Listener类

package com.bjsxt.listener;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;
/**
 * springBoot整合Listener
 */
@WebListener
public class FirstListener implements ServletContextListener {

	@Override
	public void contextDestroyed(ServletContextEvent arg0) {
		// TODO Auto-generated method stub

	}

	@Override
	public void contextInitialized(ServletContextEvent arg0) {
		System.out.println("Listener...init......");

	}

}

2.编写启动类

package com.bjsxt;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;

/**
 * springBoot整合Listener方式一
 */
@SpringBootApplication
@ServletComponentScan
public class App {

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

}

三 方法方式

1.编写Listener类

package com.bjsxt.listener;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
/**
 * springBoot整合Listener方式二。
 *
 *
 */
public class SecondListener implements ServletContextListener {

	@Override
	public void contextDestroyed(ServletContextEvent arg0) {
		// TODO Auto-generated method stub
	}

	@Override
	public void contextInitialized(ServletContextEvent arg0) {
		System.out.println("SecondListener..init.....");
	}

}

2.编写启动类

package com.bjsxt;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletListenerRegistrationBean;
import org.springframework.context.annotation.Bean;

import com.bjsxt.listener.SecondListener;

/**
 * SpringBoot整合Listener方式二
 *
 *
 */
@SpringBootApplication
public class App2 {

	public static void main(String[] args) {
		SpringApplication.run(App2.class, args);

	}
	/**
	 * 注册listener
	 */
	@Bean
	public ServletListenerRegistrationBean<SecondListener> getServletListenerRegistrationBean(){
		ServletListenerRegistrationBean<SecondListener> bean= new ServletListenerRegistrationBean<SecondListener>(new SecondListener());
		return bean;
	}
}