Re: ReDirect에서 ServletContext로 Scope 연결 해보기

[최원철]

package ex2;

import java.io.IOException;

import jakarta.servlet.ServletContext;

import jakarta.servlet.ServletException;

import jakarta.servlet.annotation.WebServlet;

import jakarta.servlet.http.HttpServlet;

import jakarta.servlet.http.HttpServletRequest;

import jakarta.servlet.http.HttpServletResponse;

// 이동방식= Forward, Redirect : 주체객체는 - request, response객체

@WebServlet("/first")

public class FirstServlet extends HttpServlet{

private ServletContext ctx; // null값 선언

//생성을 하고

@Override

public void init() throws ServletException {

System.out.println("init() 호출");

ctx = getServletContext();

}

@Override

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

System.out.println("실행이 됨");

// 페이지 이동 : redirect

// 실험 1 ) request일 때 request A와 B간의 forward이동방식일 때 scope의 값이 유지된다. ★★★

req.setAttribute("msg", "테스형!");

ctx.setAttribute("mymsg", "HI");

// ctx.getAttribute("mymsg"); => second에서 불러서 출력해보기

resp.sendRedirect("second");

}

}

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package ex2;

import java.io.IOException;

import java.io.PrintWriter;

import jakarta.servlet.ServletContext;

import jakarta.servlet.ServletException;

import jakarta.servlet.annotation.WebServlet;

import jakarta.servlet.http.HttpServlet;

import jakarta.servlet.http.HttpServletRequest;

import jakarta.servlet.http.HttpServletResponse;

@WebServlet("/second")

public class SecondServlet extends HttpServlet {

private ServletContext ctx;

@Override

public void init() throws ServletException {

ctx = getServletContext();

}

@Override

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

// req.setAttribute("key","val"); => req.getArrtribute("key");

String msg1 = req.getParameter("msg1");

resp.setContentType("text/html;charset=UTF-8");

System.out.println("여기는 SecondServlet");

PrintWriter out = resp.getWriter();

out.println("<ul>");

out.println("<li>" + req.getAttribute("msg") + "</li>");

out.println("<li>" + ctx.getAttribute("mymsg") + "</li>");

out.println("<ul>");

}

}