JSP - 게시판만들기(8) 회원가입

java

JSP - 게시판만들기(8) 회원가입

dev_summer 2020. 11. 9. 15:40

1. 주의할 점

(1) 모든 응답은 requestDispather로 한다.

이유는 주소를 남기지 않고 데이터를 들고 이동할 수 있기 때문

(2) 실패시에는 자바스크립트로 응답한다.history.back()

(3) DB의 User table의 username 제약조건에 uniq 걸어야함

alter table user add unique(username);

2. include/nav.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html lang="ko">
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet"
	href="https://maxcdn.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css">
<script
	src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
<script
	src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script>
<script
	src="https://maxcdn.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js"></script>
</head>
<body>

	<nav class="navbar navbar-expand-md bg-dark navbar-dark">
		<!-- Server/web.xml에 Welcome File List가 index.jsp로 정의 되어 있다. -->
		<a class="navbar-brand" href="<%=request.getContextPath()%>/">seoha</a>
		<button class="navbar-toggler" type="button" data-toggle="collapse"
			data-target="#collapsibleNavbar">
			<span class="navbar-toggler-icon"></span>
		</button>
		<div class="collapse navbar-collapse" id="collapsibleNavbar">
			<ul class="navbar-nav">
				<li class="nav-item"><a class="nav-link"
					href="/board?cmd=write">Post</a></li>
				<li class="nav-item"><a class="nav-link" href="/user?cmd=join">join</a>
				</li>
				<li class="nav-item"><a class="nav-link" href="/user?cmd=login">login</a>
				</li>
			</ul>
		</div>
	</nav>
	<br>

3. include/footer.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
<br />
<div class="jumbotron text-center" style="margin-bottom: 0">
	<p>made in seoha:-)</p>
</div>
</body>
</html>

4. index/.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
<%@ include file="/include/nav.jsp"%>





<%@ include file="/include/footer.jsp"%>

5. dao/USerDao.java

package com.cos.board.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Timestamp;
import java.util.ArrayList;
import java.util.List;
import com.cos.board.db.DButil;
import com.cos.board.model.User;

// User Test
// DAO -> data Access object : 데이터베이스에 접속해서 
public class UserDao {

	private UserDao() {}
	
	private static UserDao instance = new UserDao(); // 진입하는 순간 생성 된다.
	
	public static UserDao getinstance(){ // 싱글톤 패턴
		return instance;
	}
	public int save(String username, String password, String email) {
		// 1. Stream 연결
		Connection conn = DButil.getConnection();
		PreparedStatement pstmt = null;
		try {
			// 2. 쿼리 메시지 전송 클래스(규약에 맞게), sql은 쿼리
			final String SQL = "INSERT INTO user(username, password, email, createTime) VALUES(?,?,?,now())";
			pstmt = conn.prepareStatement(SQL);
			// 3. SQL문 완성하기
			pstmt.setString(1, username);
			pstmt.setString(2, password);
			pstmt.setString(3, email);
			// 4. SQL문 전송 write,read의 전송 방법이 다르다. 프로토콜이 2개 필요. executeQuery는 결과를 알려달라는 문,
			// executeUpdate는 DB에 기록하고 return이 필요없는 문
			// pstmt.executeQuery();
			int result = pstmt.executeUpdate();// PSMT가 닫힐때 DB에 자동으로 커밋 해줌.
			return result;
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			try {
				conn.close();
				// conn.commit(); 원래는 자동으로 커밋되나 두가지의 일이 한개의 트랜잭션일때는 따로 커밋해야함
				pstmt.close();
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		return -1;
	}

}
길어서 update, delete등은 뺌 깔깔

6.action/UserJoinAction.java

package com.cos.board.action.user;

import java.io.IOException;

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

import com.cos.board.action.Action;

public class UserJoinAction implements Action {

	@Override
	public void execute(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		
		// 1. 페이지 이동
		//resp.sendRedirect("/user/join.jsp"); // 주소가 남는 단점이 있다.
		
		RequestDispatcher dis = req.getRequestDispatcher("/user/join.jsp");
		dis.forward(req, resp);
	}

}

7. user/join.jsp

package com.cos.board.action.user;

import java.io.IOException;

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

import com.cos.board.action.Action;

public class UserJoinAction implements Action {

	@Override
	public void execute(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		
		// 1. 페이지 이동
		//resp.sendRedirect("/user/join.jsp"); // 주소가 남는 단점이 있다.
		
		RequestDispatcher dis = req.getRequestDispatcher("/user/join.jsp");
		dis.forward(req, resp);
	}

}

<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
<%@ include file="/include/nav.jsp"%>

<body>

	<div class="container">
		<div class="card">
			<div class="card-header">join</div>
			<div class="card-body">
				<form action="/user?cmd=joinProc" method="POST">
					<div class="form-group">
						<label for="username">Username :</label> <input type="text"
							class="form-control" placeholder="Enter username" name="username" required="required" maxlength="20">
					</div>

					<div class="form-group">
						<label for="password">Password:</label> <input type="password"
							class="form-control" placeholder="Enter password" name="password"
							required="required" maxlength="12">
					</div>

					<div class="form-group">
						<label for="email">Email address:</label> <input type="email"
							class="form-control" placeholder="Enter email" name="email"
							required="required" maxlength="30">

					</div>
					<button type="submit" class="btn btn-primary">Submit</button>
				</form>
			</div>
		</div>
	</div>
<%@include file="/include/footer.jsp"%>

8. acion/UserJoinProAction.java

package com.cos.board.action.user;

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

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

import com.cos.board.action.Action;
import com.cos.board.dao.UserDao;
import com.cos.board.util.Script;

public class UserjoinProcAction implements Action {

	@Override
	public void execute(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		// 1. 파라메터를 받기
		// 2. POST요청이기때문에 DB에 insert
		//   (1)DAO 연결
		//   (2) 함수 실행 save(username, password,email);
		//   (3)return 값이 1일때 index.jsp 이동
		//      return 값이 1이 아니면 자바스크립트로 history.back(); 
		
		
		// 1번
		String username = req.getParameter("username");
		String password = req.getParameter("password");
		String email = req.getParameter("email");
		
		System.out.println("username : "+username);
		System.out.println("password : "+password);
		System.out.println("email : "+email);
		
		
		// 2-(1)번
		UserDao userDao = UserDao.getinstance();
		
		// 2-(2)번
		int result = userDao.save(username,password,email);
		
		// 2-(3)번
		if(result==1) {
			RequestDispatcher dis = req.getRequestDispatcher("/");
			dis.forward(req, resp);
		}else {
			Script.back(resp);
		}
	}

}

9. util/Script.java

package com.cos.board.util;

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

import javax.servlet.http.HttpServletResponse;

public class Script {
	
	public static void back(HttpServletResponse resp) throws IOException {
		/* out은 response를 통해 받음. */ 
		PrintWriter out = resp.getWriter();
		out.print("<script>");
		out.print("alert('회원가입실패');");
		out.print("history.back();");
		out.print("</script>");
		out.flush();
	}
	
}

	private static UserDao instance = new UserDao(); // 진입하는 순간 생성 된다.
	
	public static UserDao getinstance(){ // 싱글톤 패턴
		return instance;
	}

- 싱글톤 패턴(동기화와 관련된 패턴)

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