package cn.bl;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

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

@SpringBootApplication

@ServletComponentScan

public class App {

    public static void main(String[] args) {

        SpringApplication.run(App.class,args);

    }

}

package cn.bl.listener;

import javax.servlet.ServletContextEvent;

import javax.servlet.ServletContextListener;

import javax.servlet.annotation.WebListener;

@WebListener

public class FirstListener implements ServletContextListener{

    @Override

    public void contextInitialized(ServletContextEvent sce) {

        System.out.println("init .. ");

    }

    @Override

    public void contextDestroyed(ServletContextEvent sce) {

        System.out.println("desroyed .. ");

    }

}

package cn.bl.listener;

import javax.servlet.ServletContextEvent;

import javax.servlet.ServletContextListener;

public class SecondListener implements ServletContextListener{

    @Override

    public void contextInitialized(ServletContextEvent sce) {

        System.out.println("second servletListener init .. ");

    }

    @Override

    public void contextDestroyed(ServletContextEvent sce) {

        System.out.println("second servletListener destroy .. ");

    }

}

package cn.bl;

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 cn.bl.listener.SecondListener;

@SpringBootApplication

public class App2 {

    public static void main(String[] args) {

        SpringApplication.run(App2.class,args);

    }

    @Bean

    public ServletListenerRegistrationBeangetBean(){

        ServletListenerRegistrationBeanbean = new ServletListenerRegistrationBean<>(new SecondListener());

        return bean;

    }

}