[스프링부트(Spring Boot)]4.request 객체

Apr 14, 2025

이미지


@Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Enumeration<String> headerNames = req.getHeaderNames();

        while (headerNames.hasMoreElements()) {
            String headerName = headerNames.nextElement();
            String headerValue = req.getHeader(headerName);
            System.out.println(headerName + ": " + headerValue);
        }
    }

이미지


@Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String path = req.getRequestURI();
        System.out.println("path: " + path);

        String method = req.getMethod();
        System.out.println("method: " + method);

        String QueryString = req.getQueryString();
        System.out.println("QueryString: " + QueryString); // 구체적 질의 =sql
        

        String username = req.getParameter("username");
        System.out.println("username: " + username);

        String password = req.getParameter("password");
        System.out.println("password: " + password);

2.포스트

텍스트로 보내기


 @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        String body = "";
        BufferedReader br = req.getReader();

        while (true) {
            String line = br.readLine();
            if (line == null) break;

            body = body + line;
        }
        System.out.println("body: " + body);
    }
}

json으로 보내기


 @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        String body = "";
        BufferedReader br = req.getReader();

        while (true) {
            String line = br.readLine();
            if (line == null) break;

            body = body + line;
        }
        String Username = req.getParameter("username");
        String Password = req.getParameter("password");
        System.out.println("Username: " + Username);
        System.out.println("Password: " + Password);
    }

x.www.-form-urlencoded 으로 보내기


@Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        System.out.println("username: " + username);
        System.out.println("password: " + password);
    }

커서 켜서 내용보내서 받기


<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <form
      action="http://localhost:8080/hello.do"
      method="post"
      enctype="application/x-www-form-urlencoded"
    >
      <input type="text" placeholder="Enter your username" name="username" />
      <input type="text" placeholder="Enter your password" name="password" />
      <button type="submit">Login</button>
    </form>
  </body>
</html>

jsp를 지우고 똑같이


<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h1>Home page</h1>
<hr>
<%
    String name = "홍길동";
%>
<%=name%>
</body>
</html>


package org.example.demo7;

import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

import java.io.IOException;

@WebServlet("/home.jsp")
public class HomeServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setHeader("Content-Type", "text/html");
        String name = "홍길동";
        String body = """
                <html>
                <head>
                    <title>Title</title>
                </head>
                <body>
                <h1>Home page</h1>
                <hr>
                ${name}
                </body>
                </html>
                """.replace("${name}", name);

        resp.getWriter().println(body);
    }
}

ds를 통해 여러 jsp를


package org.example.demo8;

import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

import java.io.IOException;


// localhost:8080/hello.do?path=a
@WebServlet("*.do")
public class FrontController extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("common logic");
        String path = req.getParameter("path");

        if (path.equals("a")) {
            req.getRequestDispatcher("a.jsp").forward(req, resp);
        } else if (path.equals("b")) {
            req.getRequestDispatcher("b.jsp").forward(req, resp);
        } else if (path.equals("c")) {
            req.getRequestDispatcher("c.jsp").forward(req, resp);
        } else {

        }
    }
}

a.jsp


<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
  <h1>A view</h1>
</body>
</html>

b.jsp


<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h1>B view</h1>
</body>
</html>

c.jsp


<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h1>C view</h1>
</body>
</html>


package org.example.second.controller;

import jakarta.servlet.http.HttpServletResponse;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseBody;


@Controller // PrintWriter 응답 @Controller -> requestDispatcher
public class DemoController {

    @GetMapping("/haha")
    public @ResponseBody String haha(){
        return "haha";
    }

    @GetMapping("/home")
    public void home(HttpServletResponse response){
        response.setStatus(302);
        response.setHeader("Location", "/haha");
    }
}

@Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { Enumeration<String> headerNames = req.getHeaderNames(); while (headerNames.hasMoreElements()) { String headerName = headerNames.nextElement(); String headerValue = req.getHeader(headerName); System.out.println(headerName + ": " + headerValue); } }

@Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { String path = req.getRequestURI(); System.out.println("path: " + path); String method = req.getMethod(); System.out.println("method: " + method); String QueryString = req.getQueryString(); System.out.println("QueryString: " + QueryString); // 구체적 질의 =sql String username = req.getParameter("username"); System.out.println("username: " + username); String password = req.getParameter("password"); System.out.println("password: " + password);

@Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { String body = ""; BufferedReader br = req.getReader(); while (true) { String line = br.readLine(); if (line == null) break; body = body + line; } String Username = req.getParameter("username"); String Password = req.getParameter("password"); System.out.println("Username: " + Username); System.out.println("Password: " + Password); }

@Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { String username = req.getParameter("username"); String password = req.getParameter("password"); System.out.println("username: " + username); System.out.println("password: " + password); }

<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8" /> <meta name="viewport" content="width=device-width, initial-scale=1.0" /> <title>Document</title> </head> <body> <form action="http://localhost:8080/hello.do" method="post" enctype="application/x-www-form-urlencoded" > <input type="text" placeholder="Enter your username" name="username" /> <input type="text" placeholder="Enter your password" name="password" /> <button type="submit">Login</button> </form> </body> </html>

<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>Title</title> </head> <body> <h1>Home page</h1> <hr> <% String name = "홍길동"; %> <%=name%> </body> </html>

package org.example.demo7; import jakarta.servlet.ServletException; import jakarta.servlet.annotation.WebServlet; import jakarta.servlet.http.HttpServlet; import jakarta.servlet.http.HttpServletRequest; import jakarta.servlet.http.HttpServletResponse; import java.io.IOException; @WebServlet("/home.jsp") public class HomeServlet extends HttpServlet { @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { resp.setHeader("Content-Type", "text/html"); String name = "홍길동"; String body = """ <html> <head> <title>Title</title> </head> <body> <h1>Home page</h1> <hr> ${name} </body> </html> """.replace("${name}", name); resp.getWriter().println(body); } }

package org.example.demo8; import jakarta.servlet.ServletException; import jakarta.servlet.annotation.WebServlet; import jakarta.servlet.http.HttpServlet; import jakarta.servlet.http.HttpServletRequest; import jakarta.servlet.http.HttpServletResponse; import java.io.IOException; // localhost:8080/hello.do?path=a @WebServlet("*.do") public class FrontController extends HttpServlet { @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { System.out.println("common logic"); String path = req.getParameter("path"); if (path.equals("a")) { req.getRequestDispatcher("a.jsp").forward(req, resp); } else if (path.equals("b")) { req.getRequestDispatcher("b.jsp").forward(req, resp); } else if (path.equals("c")) { req.getRequestDispatcher("c.jsp").forward(req, resp); } else { } } }

package org.example.second.controller; import jakarta.servlet.http.HttpServletResponse; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.ResponseBody; @Controller // PrintWriter 응답 @Controller -> requestDispatcher public class DemoController { @GetMapping("/haha") public @ResponseBody String haha(){ return "haha"; } @GetMapping("/home") public void home(HttpServletResponse response){ response.setStatus(302); response.setHeader("Location", "/haha"); } }