jsp 는 내장객체를 갖고 있따.
코드 블럭 안에 사용하면 안됨.
response
request
pageContext
session
application
config
out
- M : Model
- V : View
- C : Controller
package com.jongseo.web;
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("/spag")
public class Spag extends HttpServlet{
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
int num = 0;
String num_ = req.getParameter("n");
if(num_ != null && !num_.equals("")) {
num = Integer.parseInt(num_);
}
// model
String result ="";
if(num % 2 == 0) {
result = "짝수";
}
else {
result ="홀수";
}
//Spag.java -> spag.jsp 로 model 전
// result 저장하기.
req.setAttribute("result", result);
// express 의 middleware 같다.
RequestDispatcher dispatcher = req.getRequestDispatcher("spag.jsp");
dispatcher.forward(req, resp);
}
}
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<%=request.getAttribute("result") %>
</body>
</html>
jsp 식
<%=request.getAttribute("result") %>
-El 식
${result}
${anyListOrArray[0]}
${anyMap.keyName}
{header.host{
만약 key 값이 겹친다면
저장소 순위로 value를 가져온다.
단 임의로 저장소의 key 값을 가져오려면
{requestScope.anyKey}