Intellij JSP - Servlet Context Listener(서블릿 리스너)

Servlet Context Listener(서블릿 리스너)

• Project - ContextListener

  • Servlet.java

      import javax.servlet.ServletException;
      import javax.servlet.annotation.WebServlet;
      import javax.servlet.http.HttpServlet;
      import javax.servlet.http.HttpServletRequest;
      import javax.servlet.http.HttpServletResponse;
      import java.io.IOException;
      import java.io.PrintWriter;
    
      @WebServlet(value = "/Serv")
      public class Servlet extends HttpServlet {
    
              @Override
              public void init() throws ServletException {
                      super.init();
                      System.out.println("init!!");
              }
    
              @Override
              protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
                      super.service(req, resp);
                      System.out.println("HttpServlet Service");
              }
    
    
              protected void doPost(HttpServletRequest request, HttpServletResponse response) throws javax.servlet.ServletException, IOException {
              }
    
              protected void doGet(HttpServletRequest request, HttpServletResponse response) throws javax.servlet.ServletException, IOException {
                      PrintWriter out = response.getWriter();
                      out.println("DD GET");
                      System.out.println("doGet!!");
              }
    
              @Override
              public void destroy() {
                      super.destroy();
                      System.out.println("destroy!!");
              }
      }
    

1. Servlet Context Listener 생성

   • 마우스 우클릭 -> New -> Create New Listener

     

   • ServletContextListener 제외하고 나머지 implements 제거

       import javax.servlet.ServletContextEvent;
       import javax.servlet.ServletContextListener;
       import javax.servlet.annotation.WebListener;
     
       @WebListener()
       public class ContextListener implements ServletContextListener{
               public ContextListener() {}
     
               public void contextInitialized(ServletContextEvent sce) {
                       System.out.println("contextInitialized");
               }
     
               public void contextDestroyed(ServletContextEvent sce) {
                       System.out.println("contextDestroyed");
               }
       }
     

2. web.xml에 Context Listener 등록

    <?xml version="1.0" encoding="UTF-8"?>
    <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
                     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                     xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
                     version="4.0">
            ...
   
            <!-- 추가 -->
            <listener>
                    <listener-class>example.ContextListener</listener-class>
            </listener>
   
            ...
    </web-app>
   

• 로그로 동작여부를 확인 할 수 있다

  

• 신입SW인력을 위한 실전 JSP Servlet