Servlet 만들기

[Spring] Servlet 만들기

Jan 25, 2024

Contents

프로젝트 생성 ContextPath 설정

프로젝트 생성

ContextPath 설정

Dispatcher


package org.example.demo2;

import jakarta.servlet.http.HttpServletResponse;

import java.io.IOException;

// 라우팅
public class Dispatcher {

    public static void route(String cmd, String action, HttpServletResponse resp) throws IOException {
        if(cmd.equals("user")){
            UserController con = new UserController();

            if(action.equals("login")){
                String html = con.login();
                resp.getWriter().println(html);
            }else if(action.equals("join")){
                String html = con.join();
                resp.getWriter().println(html);
            }


        }else if(cmd.equals("board")){
            resp.getWriter().println("<h1>board</h1>");
        }
    }
}

FrontController


package org.example.demo2;

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;
import java.io.PrintWriter;

@WebServlet("/*")
public class FrontController extends HttpServlet {

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setHeader("Content-Type", "text/html; charset=utf-8");

        String cmd = req.getParameter("cmd");
        String action = req.getParameter("action");
        Dispatcher.route(cmd, action, resp);
    }
}

UserController


package org.example.demo2;

public class UserController {

    public String login(){
        return "<h1>login</h1>";
    }

    public String join(){
        return "<h1>join</h1>";
    }
}

http://localhost:8080/?cmd=user&action=login

→ 일반적으로 쿼리 스트링으로 사용하면 255자까지 밖에 못적기 때문에 데이터를 주소로 보내지는 않음.

package org.example.demo2; import jakarta.servlet.http.HttpServletResponse; import java.io.IOException; // 라우팅 public class Dispatcher { public static void route(String cmd, String action, HttpServletResponse resp) throws IOException { if(cmd.equals("user")){ UserController con = new UserController(); if(action.equals("login")){ String html = con.login(); resp.getWriter().println(html); }else if(action.equals("join")){ String html = con.join(); resp.getWriter().println(html); } }else if(cmd.equals("board")){ resp.getWriter().println("<h1>board</h1>"); } } }

package org.example.demo2; 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; import java.io.PrintWriter; @WebServlet("/*") public class FrontController extends HttpServlet { @Override protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { resp.setHeader("Content-Type", "text/html; charset=utf-8"); String cmd = req.getParameter("cmd"); String action = req.getParameter("action"); Dispatcher.route(cmd, action, resp); } }