[JSP. Servlet] #6 servlet 선 ,후처리 init() - service() - destroy()

 

 

servlet 선처리 (init()전), 후처리 (destroy()후)

 

객체생성 -  init() -- service() -- destroy()

 

선처리를 위한 어노테이션  @PostConstruct, 

후처리를 위한 어노테이션  @PreDestroy

 

선처리   의존하는 객체를 설정한 이후에 초기화 작업을 수행할 메서드에 적응 

후처리   컨테이너에서 객체를 제거하기 전에 호출 된 메서드에 적응

 

 

 

TEST

 

 

 

package com.test.ex;

import java.io.IOException;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class Cycle_Ex
 */
@WebServlet("/Cycle_Ex")
public class Cycle_Ex extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public Cycle_Ex() {
        super();
        // TODO Auto-generated constructor stub
    }
    @Override
    public void init() throws ServletException {
    	System.out.println("init호출");
    }
    
 /*   @Override
    public void service(ServletRequest req, ServletResponse res) throws ServletException, IOException {
    	System.out.println("service() 호출");
    }
  */  
    
	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    	System.out.println("doGet호출");		
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    	System.out.println("doPost호출");		
	}
	
	@Override
	public void destroy() {
		System.out.println("destroy 호출");
	}
	
	@PostConstruct
	public void initMethod() {
		System.out.println("postConstruct 호출");
	}

	@PreDestroy
	private void preDestory() {
		System.out.println("preDestory 호출");
	}
	
}