12day JSP

1. filter
필터 생성시 인터페이스 상속받음

서블릿 필터

package filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class FilterEx01 implements Filter {

 @Override
 public void destroy() {
  // 클래스 메모리 제거시 호출
  System.out.println("destory()");
 }

 @Override
 public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)
   throws IOException, ServletException {
  
  //request 처리
  System.out.println("전처리 부분");
  
  arg2.doFilter(arg0, arg1);
  
  //response 처리
  System.out.println("후처리부분");
 }

 @Override
 public void init(FilterConfig arg0) throws ServletException {
  // 클래스 생성시 자동 호출
  System.out.println("init()");
 }

}

필터 등록

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>FilterEx01</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <!-- 필터 web.xml 등록 -->
  <filter>
      <filter-name>FirstFilter</filter-name>
      <filter-class>filter.FilterEx01</filter-class>
  </filter>
  <filter-mapping>
      <filter-name>FirstFilter</filter-name>
      <url-pattern>*.jsp</url-pattern>
  </filter-mapping>
</web-app>

test.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%
    System.out.println("Hello Filter");
    out.println("Hello Filter");
%>

2. 필터가 여러개
filterEx01

package filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class FilterEx01 implements Filter {

 @Override
 public void destroy() {
  // 클래스 메모리 제거시 호출
  System.out.println("destory1()");
 }

 @Override
 public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)
   throws IOException, ServletException {
  
  //request 처리
  System.out.println("전처리 부분1");
  
  arg2.doFilter(arg0, arg1);
  
  //response 처리
  System.out.println("후처리부분1");
 }

 @Override
 public void init(FilterConfig arg0) throws ServletException {
  // 클래스 생성시 자동 호출
  System.out.println("init1()");
 }

}

filterEx01

package filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class FilterEx02 implements Filter {

 @Override
 public void destroy() {
  // 클래스 메모리 제거시 호출
  System.out.println("destory2()");
 }

 @Override
 public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)
   throws IOException, ServletException {
  
  //request 처리
  System.out.println("전처리 부분2");
  
  arg2.doFilter(arg0, arg1);
  
  //response 처리
  System.out.println("후처리부분2");
 }

 @Override
 public void init(FilterConfig arg0) throws ServletException {
  // 클래스 생성시 자동 호출
  System.out.println("init2()");
 }

}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>FilterEx01</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <!-- 필터 등록 -->
  <!-- FilterEx02 2번을 먼저 등록함 //web.xml에 등록한 순서로 필터가 체인식으로 적용됨 -->
  <filter>
      <filter-name>FirstFilter</filter-name>
      <filter-class>filter.FilterEx02</filter-class>
  </filter>
  <filter-mapping>
      <filter-name>FirstFilter</filter-name>
      <url-pattern>*.jsp</url-pattern>
  </filter-mapping>
  <!-- 필터 등록 -->
  <filter>
      <filter-name>SecondFilter</filter-name>
      <filter-class>filter.FilterEx01</filter-class>
  </filter>
  <filter-mapping>
      <filter-name>SecondFilter</filter-name>
      <url-pattern>*.jsp</url-pattern>
  </filter-mapping>
</web-app>

test.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%
    System.out.println("Hello Filter");
    out.println("Hello Filter");
%>

3.필터 초기값 전처리

package filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class FilterEx01 implements Filter {
 private String id;
 private String password;
 
 @Override
 public void destroy() {

 }

 @Override
 public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)
   throws IOException, ServletException {
  //실행순서 2
  //필터 전처리
  arg0.setAttribute("id", "전처리된 아이디 "+id);
  arg0.setAttribute("password", "전처리된 비밀번호 "+password);
  
  arg2.doFilter(arg0, arg1);
  
  //실행순서 4
  System.out.println((String)arg0.getAttribute("id"));
  System.out.println((String)arg0.getAttribute("password"));
  
 }

 @Override
 public void init(FilterConfig arg0) throws ServletException {
  //실행순서 1
  //web.xml 설정된 초기데이터 읽어오기
  id = arg0.getInitParameter("id");
  password = arg0.getInitParameter("password");
  
  System.out.println("읽어온 아이디 : "+ id);
  System.out.println("읽어온 비밀번호 : "+ password);
 }

}

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>FilterEx02</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <!-- 필터 등록, 초기값 세팅 -->
  <filter>
      <filter-name>filter</filter-name>
      <filter-class>filter.FilterEx01</filter-class>
      <init-param>
          <param-name>id</param-name>
          <param-value>scott</param-value>
      </init-param>
      <init-param>
          <param-name>password</param-name>
          <param-value>tiger</param-value>
      </init-param>
  </filter>
  <filter-mapping>
      <filter-name>filter</filter-name>
      <url-pattern>*.jsp</url-pattern>
  </filter-mapping>
</web-app>

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%
    //실행순서 3
    String id = (String)request.getAttribute("id");
    String password    = (String)request.getAttribute("password");
    
    request.setAttribute("id", "리턴된 "+ id);
    request.setAttribute("password", "리턴된 "+ password);
%>
<!DOCTYPE html>
<html lang="ko">
<head>
<meta name="viewport" content="width=device-width,initial-scale=1.0,minimum-scale=1.0,maximum-scale=1.0">
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<%= id + " / " +password %>
</body>
</html>

init1(), init2()은 다른 프로젝트 폴더에 있는 필터 클래스 이지만 톰캣이 전체 프로젝트를 실행함으로 호출이됨
4. dispatcher

package filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class FilterEx01 implements Filter {

 @Override
 public void destroy() {

 }

 @Override
 public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)
   throws IOException, ServletException {
  
  //결과를 없애고 새로운 방향으로 바꿈
  //test.jsp ▶ error.jsp
  RequestDispatcher dispatcher = arg0.getRequestDispatcher("error.jsp");
  dispatcher.forward(arg0, arg1);
 }

 @Override
 public void init(FilterConfig arg0) throws ServletException {

 }

}

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>FilterEx03</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <!-- 필터 등록, 초기값 세팅 -->
  <filter>
      <filter-name>filter</filter-name>
      <filter-class>filter.FilterEx01</filter-class>
  </filter>
  <filter-mapping>
      <filter-name>filter</filter-name>
      <url-pattern>*.jsp</url-pattern>
  </filter-mapping>
</web-app>

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html lang="ko">
<head>
<meta name="viewport" content="width=device-width,initial-scale=1.0,minimum-scale=1.0,maximum-scale=1.0">
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
    난 test.jsp
</body>
</html>

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html lang="ko">
<head>
<meta name="viewport" content="width=device-width,initial-scale=1.0,minimum-scale=1.0,maximum-scale=1.0">
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
    난 error.jsp
</body>
</html>

5. 필터의 활용: 모든페이지에 한글 인코딩 적용
form.htm

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
    <center>
        <form name="data_form" method="post" action="Servlet_01">
            이름: <input type="text" name="name" /><br>
            전번: <input type="text" name="tel" /><br>
            주소: <input type="text" name="addr" /><br>
            <input type="submit" value="전송" />
        </form>
    </center>
</body>
</html>

servlet

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ServletEx01 extends HttpServlet {

    @Override
    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String name = request.getParameter("name");
        String tel = request.getParameter("tel");
        String addr = request.getParameter("addr");
        
        response.setContentType("text/html; charset=utf-8");
        PrintWriter out = response.getWriter();
        out.println("<html>");
        out.println("<head>");
        out.println("<style type='text/css'>");
        out.println(".n_border {border:none}");
        out.println("</style>");
        out.println("</head>");
        out.println("<body>");
        out.println("    <center>");
        out.println("        전송된 이름 =");
        out.println("        <input type='text' class='n_border' value='"+name +"'/><br>");
        out.println("        전송된 전번 =");
        out.println("        <input type='text' class='n_border' value='"+tel +"'/><br>");
        out.println("        전송된 주소 =");
        out.println("        <input type='text' class='n_border' value='"+addr +"'/><br>");
        out.println("    </center>");
        out.println("</body>");
        out.println("</html>");

    }

    @Override
    public void destroy() {    }

    @Override
    public void init() { }

}

filter

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

public class FilterEx01 implements Filter {

 @Override
 public void destroy() {

 }

 @Override
 public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
   throws IOException, ServletException {

  HttpServletRequest h_request = (HttpServletRequest)request;
  String method = h_request.getMethod();
  if(method.equalsIgnoreCase("POST")){
   request.setCharacterEncoding("utf-8");
  }
  chain.doFilter(request, response);
    
 }

 @Override
 public void init(FilterConfig arg0) throws ServletException {

 }

}

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>FilterEx00</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
   <!-- 서블릿 등록 -->
  <servlet>
      <servlet-name>MyServlet</servlet-name>
      <servlet-class>ServletEx01</servlet-class>
  </servlet>
  <servlet-mapping>
      <servlet-name>MyServlet</servlet-name>
      <url-pattern>/Servlet_01</url-pattern>
  </servlet-mapping>
  <!-- 필터 등록 -->
  <filter>
      <filter-name>MyFilter</filter-name>
      <filter-class>FilterEx01</filter-class>
  </filter>
  <filter-mapping>
      <filter-name>MyFilter</filter-name>
      <url-pattern>/Servlet_01</url-pattern>
  </filter-mapping>
</web-app>

6.Listener

클래스를 만들때 인터페이스 상속

package listener;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

public class ListenerEx01 implements ServletContextListener {

 @Override
 public void contextDestroyed(ServletContextEvent arg0) {
  //웹 컨테이너가 끝났을 때 실행
  System.out.println("contextDestroyed 호출");
 }

 @Override
 public void contextInitialized(ServletContextEvent arg0) {
  //웹 컨테이너가 시작시
  System.out.println("contextInitialized 호출");
 }

}

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>ListenerEx01</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <listener>
      <listener-class>listener.ListenerEx01</listener-class>
  </listener>
</web-app>

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html lang="ko">
<head>
<meta name="viewport" content="width=device-width,initial-scale=1.0,minimum-scale=1.0,maximum-scale=1.0">
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
    test.jsp context 리스너
</body>
</html>

package listener;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

public class ListenerEx01 implements ServletContextListener {

 @Override
 public void contextDestroyed(ServletContextEvent arg0) {
  //웹 컨테이너가 끝났을 때 실행
  System.out.println("contextDestroyed 호출");
 }

 
 //context 내용 변화
 
 
 @Override
 public void contextInitialized(ServletContextEvent arg0) {
  //웹 컨테이너가 시작시
  System.out.println("contextInitialized 호출");
 }

}

7.attribute listener 속성값이 변할때 마다 호출

listener

import javax.servlet.ServletContextAttributeEvent;
import javax.servlet.ServletContextAttributeListener;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

public class Servlet_Listener implements ServletContextListener, ServletContextAttributeListener {

 @Override
 public void attributeAdded(ServletContextAttributeEvent arg0) {
  // TODO Auto-generated method stub
  System.out.println("Context 영역에 값이 추가 되었습니다.");
  System.out.println("added = " +arg0.getName()+" : " + arg0.getValue());
 }

 @Override
 public void attributeRemoved(ServletContextAttributeEvent arg0) {
  // TODO Auto-generated method stub
  System.out.println("Context 영역에 값이 삭제 되었습니다.");
  System.out.println("removed = " +arg0.getName()+" : " + arg0.getValue());
 }

 @Override
 public void attributeReplaced(ServletContextAttributeEvent arg0) {
  // TODO Auto-generated method stub
  System.out.println("Context 영역에 값이 변경 되었습니다.");
  System.out.println("replaced = " +arg0.getName()+" : " + arg0.getValue());
 }

 @Override
 public void contextDestroyed(ServletContextEvent arg0) {
  // TODO Auto-generated method stub
  System.out.println("ServletContext 가 소멸 되었습니다.");
  System.out.println("destroy context = " +arg0.getServletContext());
 }

 @Override
 public void contextInitialized(ServletContextEvent arg0) {
  // TODO Auto-generated method stub
  System.out.println("ServletContext 가 초기화 되었습니다.");
  System.out.println("init context = " +arg0.getServletContext());

 }

}

servlet

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ServletEx01 extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setContentType("text/html;charset=utf-8");
        PrintWriter out = resp.getWriter();
        out.println("<html><body><center>");
        out.println("<form method='post'>");
        out.println("<input type='submit' value='Context 값 할당하기' />");
        out.println("</form>");
        out.println("</center></body></html>");
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        ServletContext context = this.getServletContext();
        context.setAttribute("my_name", "김승현");
        context.setAttribute("my_name", "승현");
        context.removeAttribute("my_name");
        
        resp.setContentType("text/html;charset=utf-8");
        PrintWriter out = resp.getWriter();
        out.println("<html><body><center>");
        out.println("Context 값 추가, 변경, 삭제 성공!");
        out.println("</center></body></html>");
    }

}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>ListenerEx02</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
   <!-- 리스너 등록  -->
  <listener>
      <listener-class>Servlet_Listener</listener-class>
  </listener>
   <!-- 서블릿 등록 -->
  <servlet>
      <servlet-name>MyServlet</servlet-name>
      <servlet-class>ServletEx01</servlet-class>
  </servlet>
  <servlet-mapping>
      <servlet-name>MyServlet</servlet-name>
      <url-pattern>/ServletEx01</url-pattern>
  </servlet-mapping>
</web-app>

8.model2

package servlet;

import java.io.IOException;
import java.io.UnsupportedEncodingException;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class ControllerEx01
 */
@WebServlet("/controller")
public class ControllerEx01 extends HttpServlet {
 private static final long serialVersionUID = 1L;

 /**
  * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
  */
 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  doProcess(request, response);
 }

 /**
  * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
  */
 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  doProcess(request, response);
 }
 
 protected void doProcess(HttpServletRequest request, HttpServletResponse response) {
  //메서드 안에서 예외 처리를 해줘서 에러메시지 볼수 있도록 함
  
  //뒤에 붙은 값에 따라서 서로다른 웹페이지로 이동
  //http://localhost/ParameterEx01/controller
  //http://localhost/ParameterEx01/controller?action=view1  → view1.jsp
  //http://localhost/ParameterEx01/controller?action=view2  → view2.jsp
  
  try {
   request.setCharacterEncoding("utf-8");
   
   String action = request.getParameter("action");
   String url = "";
   if(action == null || action.equals("view1")){
    url = "view1.jsp";
   }else if(action.equals("view2")){
    url = "view2.jsp";
   }
   
   if(!url.equals("")){
    //와 비슷함 출력을 바꿔서 보여줌
    //서블릿에서 각각다른 JSP페이지를 봄
    RequestDispatcher dispatcher = request.getRequestDispatcher(url);
    dispatcher.forward(request, response);
   }
  } catch (UnsupportedEncodingException e) {
   System.out.println("에러 : "+ e.getMessage());
  } catch (ServletException e) {
   System.out.println("에러 : "+ e.getMessage());
  } catch (IOException e) {
   System.out.println("에러 : "+ e.getMessage());
  }
 }
}

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html lang="ko">
<head>
<meta name="viewport" content="width=device-width,initial-scale=1.0,minimum-scale=1.0,maximum-scale=1.0">
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
    난 view1.jsp
</body>
</html>

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html lang="ko">
<head>
<meta name="viewport" content="width=device-width,initial-scale=1.0,minimum-scale=1.0,maximum-scale=1.0">
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
    난 view2.jsp
</body>
</html>

9. controller에서 model 접속후 view 띄우기

package servlet;

import java.io.IOException;
import java.io.UnsupportedEncodingException;

import javax.servlet.RequestDispatcher;
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 model.view1Model;

@WebServlet("/controller")
public class ControllerEx01 extends HttpServlet {
 private static final long serialVersionUID = 1L;

 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  doProcess(request, response);
 }

 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  doProcess(request, response);
 }
 
 protected void doProcess(HttpServletRequest request, HttpServletResponse response) {
  //메서드 안에서 예외 처리를 해줘서 에러메시지 볼수 있도록 함
  
  //뒤에 붙은 값에 따라서 서로다른 웹페이지로 이동
  //http://localhost/ParameterEx01/controller
  //http://localhost/ParameterEx01/controller?action=view1  → view1.jsp
  //http://localhost/ParameterEx01/controller?action=view2  → view2.jsp
  
  try {
   request.setCharacterEncoding("utf-8");
   
   String action = request.getParameter("action");
   String url = "";
   if(action == null || action.equals("view1")){
    //Model 호출
    view1Model viewModel = new view1Model();
    viewModel.execute(request,  response);
    
    //View 호출 //JSP페이지를 직접 접속하지 못하게 WEB-INF 폴더에 넣어둠
    url = "/WEB-INF/view1.jsp";
   }else if(action.equals("view2")){
    view1Model viewModel = new view1Model();
    viewModel.execute(request,  response);
    
    url = "/WEB-INF/view2.jsp";
   }
   
   if(!url.equals("")){
    //와 비슷함 출력을 바꿔서 보여줌
    //서블릿에서 각각다른 JSP페이지를 봄
    RequestDispatcher dispatcher = request.getRequestDispatcher(url);
    dispatcher.forward(request, response);
   }
  } catch (UnsupportedEncodingException e) {
   System.out.println("에러 : "+ e.getMessage());
  } catch (ServletException e) {
   System.out.println("에러 : "+ e.getMessage());
  } catch (IOException e) {
   System.out.println("에러 : "+ e.getMessage());
  }
 }
}

package model;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class view1Model {
 public void execute(HttpServletRequest request, HttpServletResponse response){
  System.out.println("View1Model 호출");
 }
}

package model;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class view2Model {
 public void execute(HttpServletRequest request, HttpServletResponse response){
  System.out.println("View2Model 호출");
 }
}

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html lang="ko">
<head>
<meta name="viewport" content="width=device-width,initial-scale=1.0,minimum-scale=1.0,maximum-scale=1.0">
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
    난 view1.jsp
</body>
</html>

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html lang="ko">
<head>
<meta name="viewport" content="width=device-width,initial-scale=1.0,minimum-scale=1.0,maximum-scale=1.0">
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
    난 view2.jsp
</body>
</html>

10.controller, model, view 간의 데이터 공유

form

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html lang="ko">
<head>
<meta name="viewport" content="width=device-width,initial-scale=1.0,minimum-scale=1.0,maximum-scale=1.0">
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>

<!-- controller로 데이터 보냄 -->
<form action='./controller' method='post'>
<input type='hidden' name='action' value='view1' />
    아이디 : <input type='text' name='id' />
    패스워드 : <input type='text' name='password' />
    <input type='submit' value='전송' />
</form>

</body>
</html>

controller

package servlet;

import java.io.IOException;
import java.io.UnsupportedEncodingException;

import javax.servlet.RequestDispatcher;
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 model.ViewModel;
import model.view1Model;

@WebServlet("/controller")
public class ControllerEx01 extends HttpServlet {
 private static final long serialVersionUID = 1L;

 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  doProcess(request, response);
 }

 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  doProcess(request, response);
 }
 
 protected void doProcess(HttpServletRequest request, HttpServletResponse response) {
  //메서드 안에서 예외 처리를 해줘서 에러메시지 볼수 있도록 함
  
  //뒤에 붙은 값에 따라서 서로다른 웹페이지로 이동
  //http://localhost/ParameterEx01/controller
  //http://localhost/ParameterEx01/controller?action=view1  → view1.jsp
  //http://localhost/ParameterEx01/controller?action=view2  → view2.jsp
  
  try {
   request.setCharacterEncoding("utf-8");
   
   String action = request.getParameter("action");
   String url = "";
   //인터페이스 참조변수
   ViewModel viewModel =null;
   
   if(action == null || action.equals("view1")){
    //Model 호출
    viewModel = new view1Model();
    viewModel.execute(request,  response);
    
    //View 호출 //JSP페이지를 직접 접속하지 못하게 WEB-INF 폴더에 넣어둠
    url = "/WEB-INF/view1.jsp";
   }else if(action.equals("view2")){
    viewModel = new view1Model();
    viewModel.execute(request,  response);
    
    url = "/WEB-INF/view2.jsp";
   }
   
   if(!url.equals("")){
    //와 비슷함 출력을 바꿔서 보여줌
    //서블릿에서 각각다른 JSP페이지를 봄
    RequestDispatcher dispatcher = request.getRequestDispatcher(url);
    dispatcher.forward(request, response);
   }
  } catch (UnsupportedEncodingException e) {
   System.out.println("에러 : "+ e.getMessage());
  } catch (ServletException e) {
   System.out.println("에러 : "+ e.getMessage());
  } catch (IOException e) {
   System.out.println("에러 : "+ e.getMessage());
  }
 }
}

model_interface

package model;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

//Model 1, 2가 같은매서드를 사용함으로 인터페이스로 합침
public interface ViewModel {
 public abstract void execute(HttpServletRequest request, HttpServletResponse response);
 
}

model1

package model;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class view1Model implements ViewModel {

 @Override
 public void execute(HttpServletRequest request, HttpServletResponse response) {
  System.out.println("View1Model 호출");
  
  //controller에서  model로 넘어온 데이터 받음
  System.out.println("id :" + request.getParameter("id"));
  System.out.println("password :" + request.getParameter("password"));
  
  //model에서 view로 데이터 보낼때
  request.setAttribute("url", "View1Model");
 }
 
}

model2

package model;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class view2Model implements ViewModel {

 @Override
 public void execute(HttpServletRequest request, HttpServletResponse response) {
  System.out.println("View1Model 호출");
 }
 
}

view1

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html lang="ko">
<head>
<meta name="viewport" content="width=device-width,initial-scale=1.0,minimum-scale=1.0,maximum-scale=1.0">
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
    난 view1.jsp<br>
    <!-- controller에서 view로 넘어온 데이터 받음 -->
    <%=request.getParameter("id") %><br>
    <%=request.getParameter("password") %><br>
    
    <!-- model에서 넘어온 데이터 받음 -->
    <%=request.getAttribute("url") %><br>
    ${url }
    
</body>
</html>

view2

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html lang="ko">
<head>
<meta name="viewport" content="width=device-width,initial-scale=1.0,minimum-scale=1.0,maximum-scale=1.0">
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
    난 view2.jsp
</body>
</html>

11.요청url 따라서 다른 url경로의 view페이지 전송

package servlet;

import java.io.IOException;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("*.do")
public class ControllerEx01 extends HttpServlet {
 private static final long serialVersionUID = 1L;

 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  doProcess(request, response);
 }

 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  doProcess(request, response);
 }
 
 protected void doProcess(HttpServletRequest request, HttpServletResponse response) {
  //http://localhost/URLEx01/view1.do  → view1.jsp
  //http://localhost/URLEx01/view2.do  → view2.jsp
  
  //System.out.println(request.getRequestURI());
  //System.out.println(request.getContextPath());
  try {
   request.setCharacterEncoding("utf-8");
   
   String path = request.getRequestURI().replaceAll(request.getContextPath(), "");
   
   String url = "";
   if(path.equals("/view1.do")){
    url= "/WEB-INF/view1.jsp";
   }else if(path.equals("/view2.do")){
    url= "/WEB-INF/view2.jsp";
   }
   
   if(!url.equals("")){
    RequestDispatcher dispatcher = request.getRequestDispatcher(url);
    dispatcher.forward(request, response);
   }
  } catch (ServletException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
  
 }

}

view1

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html lang="ko">
<head>
<meta name="viewport" content="width=device-width,initial-scale=1.0,minimum-scale=1.0,maximum-scale=1.0">
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
    난 view1.jsp
</body>
</html>

view2

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html lang="ko">
<head>
<meta name="viewport" content="width=device-width,initial-scale=1.0,minimum-scale=1.0,maximum-scale=1.0">
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
    난 view2.jsp
</body>
</html>