2012-4-25 dispatch예제[실습]

프로그래밍/JSP Programming

2012-4-25 dispatch예제[실습]

조은성 2012. 4. 25. 15:42

package servlet.dispatch;

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

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

/**
* Servlet implementation class ErrorPronServlet
*/
public class ErrorPronServlet extends HttpServlet {
private static final long serialVersionUID = 1L;

    public ErrorPronServlet() {
        super();
    }

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

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  String choose = request.getParameter("choose");
  if(choose == null){
   //오류메세지를 request scope에 binding
   request.setAttribute("error_message", "체크박스가 선택되지 않았습니다.");
   //error.jsp로 수행을 이동 - request scope를 이용하므로 요청디스패치 방식으로 이동
   RequestDispatcher rdp = request.getRequestDispatcher("/dispatch/error.jsp");// /로 시작하면 절대 경로
   rdp.forward(request, response);
   return;
  }
  response.setContentType("text/html;charset=utf-8");
  PrintWriter out = response.getWriter();
  out.println("<html><body>");
  out.println("체크박스가 체크되어 넘어왔습니다."+choose);
  out.println("</body></html>");

}

}

<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
오류가 발생했습니다. 관리자에게 문의하세요.<br>
오류내용 :
<%
String errorMessage = (String)request.getAttribute("error_message");
%>
<%=errorMessage %>
</body>
</html>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="/myweb/error_pron_dispatch" method="post">
체크 <input type="checkbox" name="choose" value="yes">
<input type="submit" value="전송">
</form>
</body>
</html>

* 만약 redirect 방식으로 보내는 작업을 해주면 요청을 받고 응답을 하고 나면 바로 Attribute가 사라지므로 null 이 들어간다.

package servlet.dispatch;

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

/**
* Servlet implementation class ErrorPronServlet
*/
public class ErrorPronServlet extends HttpServlet {
private static final long serialVersionUID = 1L;

    public ErrorPronServlet() {
        super();
    }

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

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  String choose = request.getParameter("choose");
  if(choose == null){
   //오류메세지를 request scope에 binding
   request.setAttribute("error_message", "체크박스가 선택되지 않았습니다.");
//   //error.jsp로 수행을 이동 - request scope를 이용하므로 요청디스패치 방식으로 이동
//   RequestDispatcher rdp = request.getRequestDispatcher("/dispatch/error.jsp");// /로 시작하면 절대 경로
//   rdp.forward(request, response);
   response.sendRedirect("/myweb/dispatch/error.jsp");
   return;
  }
  response.setContentType("text/html;charset=utf-8");
  PrintWriter out = response.getWriter();
  out.println("<html><body>");
  out.println("체크박스가 체크되어 넘어왔습니다."+choose);
  out.println("</body></html>");

}

}