Wed/Feb/05 [Java] day25. DAO Model 활용

Wed/Feb/05

[Java] day25.

 - Java

 

DATABASE

DAO와 DTO

DTO : Data Transfer Object → JoinModel.java

• DB안에 있는 table의 field 값들을 이동

• VO (Value Object) 객체 / Java Beans 객체 / MVC pattern의 Model 객체

• Frame-work

  • DB관련 = myBatis

  • Code/개발 관련 = Spring

  • 전자정부2.0~현재까지 표준 = myBatis+Spring

  • 과거 전자정부 표준 = Hibanate(DB) + Struts(개발)

• 주의점

  • 모든 변수는 private 접근 제한자 - getter / setter 반드시 존재

  • sql table field 명과 동일하게 변수 선언

 

DAO - DB Class → JoinDAO.java

• 지금까지는 1개 project 에 1개 table만 실습했지만,

• 실무에서는 다수의 table 사용 - 다수의 DB Class / Servlet 필요

 

* XML 문서 특징

• 태그 X

• 선언문 : <?xml **** ?>

• 확장자 : .xml

• RSS / ATOM 등에서 사용; 회사별로 태그 만들어줌

• Schema : W3에서 만든 기본 Schema 이용 ;

• eclipse 등 에디터에서 오류 안 잡아주고, 오류시 심각한 오류 가능성 ; 띄어쓰기 오타 반드시 주의!

 

<web-app 
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns="http://xmlns.jcp.org/xml/ns/javaee"
	xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
	id="WebApp_ID" version="3.1">

• xml 수정 시 서버 재가동 필수

 

DAO 예제) 회원가입 입력과 목록

• 단순 가입 버튼 클릭 - doGet() - response.sendRedirect("")

• Write Form <FORM method = "POST" > - doPost()

mySQL file

joinDAO.java

/*
 * 회원 가입 DAO Class (DB Query 실행)
 * @since 2020.02.05
 * @author 위정훈
 */

package com.wjh.dao;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;

import com.wjh.model.JoinModel;

public class JoinDAO {

	public JoinDAO() {

	}

	private Connection conn = null;
	private Statement stmt = null;
	private PreparedStatement pstmt = null;
	private ResultSet rs = null;

	private final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
	private final String DB_URL = "jdbc:mysql://localhost:3306/dao_db";
	private final String DB_ID = "root";
	private final String DB_PW = "1234";

	/*
	 * 사용할 객체 close
	 * 
	 * @param rs
	 * 
	 * @param stmt
	 * 
	 * @param pstmt
	 * 
	 * @param conn
	 * 
	 * 최근 사용한 것부터 차례대로 close,
	 * 사용하지 않은 객체 parameter에는 null 값 입력하면 됨
	 */

	public void close(ResultSet rs, Statement stmt, PreparedStatement pstmt, Connection conn) {
		if (rs != null) {
			try {
				rs.close();
			} catch (SQLException e) {
				System.out.println("ERR_rs.close : " + e.getMessage());
			}
		}

		if (stmt != null) {
			try {
				stmt.close();
			} catch (SQLException e) {
				System.out.println("ERR_stmt.close : " + e.getMessage());
			}
		}

		if (pstmt != null) {
			try {
				pstmt.close();
			} catch (SQLException e) {
				System.out.println("ERR_pstmt.close : " + e.getMessage());
			}
		}

		if (conn != null) {
			try {
				conn.close();
			} catch (SQLException e) {
				System.out.println("ERR_conn.close : " + e.getMessage());
			}
		}
	}

	private void connectDAO() {

		try {
			Class.forName(JDBC_DRIVER);
			conn = DriverManager.getConnection(DB_URL, DB_ID, DB_PW);
//			System.out.println("SUCCESS_get_conn");

		} catch (ClassNotFoundException e) {
			System.out.println("ERR_get_conn_DriverLoading" + e.getMessage());
		} catch (SQLException e) {
			System.out.println("ERR_get_conn_DBConnection" + e.getMessage());
		}

	} // get_conn

	/*
	 * DB table 조회
	 */

	public ArrayList<JoinModel> select_all() {
		this.connectDAO();
		String query = "select * from dao_table";
		
		// ArrayList를 사용하여 ResultSet을 JoinModel 객체에 저장
		ArrayList<JoinModel> list = null;
		
		try {
			this.stmt = this.conn.createStatement();
			this.rs = stmt.executeQuery(query);
			
			list = new ArrayList<JoinModel>();
			while(rs.next()){
				
				JoinModel jm = new JoinModel();
				
				jm.set_num(rs.getInt(1));
				jm.set_id(rs.getString(2));
				jm.set_pw(rs.getString(3));
				jm.set_email(rs.getString(4));
				jm.set_phone(rs.getString(5));
				
				list.add(jm);
			} // while
			
		} catch (SQLException e) {
			System.out.println("ERR_select_all : " + e.getMessage());
		} finally {
			this.close(rs, stmt, null, conn);
		}
		return list;
	}

	/*
	 * DB table insert joinModel에서 초기값을 ""로 설정했기 때문에 값이 없는 parameter를 넣어도 실행됨
	 */

	public void insert(JoinModel joinModel) {
		this.connectDAO();
		String query = "insert into dao_table (id, pw, email, phone) values (?, ?, ?, ?)";
		try {
			
			System.out.println("ID___"+joinModel.get_id());
			System.out.println("PW___"+joinModel.get_pw());
			System.out.println("EMAIL___"+joinModel.get_email());
			System.out.println("PHONE___"+joinModel.get_phone());
			
			
			this.pstmt = this.conn.prepareStatement(query);
			this.pstmt.setString(1, joinModel.get_id());
			this.pstmt.setString(2, joinModel.get_pw());
			this.pstmt.setString(3, joinModel.get_email());
			this.pstmt.setString(4, joinModel.get_phone());
			this.pstmt.executeUpdate();
		} catch (SQLException e) {
			System.out.println("ERR_insert : " + e.getMessage());
		} finally {
			this.close(null, null, pstmt, conn);
		}

	} // insert()

}

joinModel.java > getter - setter

public class JoinModel {

	public JoinModel() {

	}

	private int num = 0;
	private String id = "";
	private String pw = "";
	private String email = "";
	private String phone = "";

	public int get_num() {
		return num;
	}

	public void set_num(int num) {
		this.num = num;
	}
	
	public String get_id() {
		return id;
	}

	public void set_id(String id) {
		this.id = id;
	}

	public String get_pw() {
		return pw;
	}

	public void set_pw(String pw) {
		this.pw = pw;
	}

	public String get_email() {
		return email;
	}

	public void set_email(String email) {
		this.email = email;
	}

	public String get_phone() {
		return phone;
	}

	public void set_phone(String phone) {
		this.phone = phone;
	}
}

index.html > doGET

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Index.html</title>
</head>
<body>
	<div align="center">
		<h1>.GET TEST</h1>
		
		<fieldset>
		<legend>JoinInsertServlet 을 GET 방식으로 요청</legend>
		<br>↓↓↓ CLICK ↓↓↓<br>
		<br> <input type="button" VALUE="WRITE"
			onclick="location.href = 'insert'" />
		</fieldset><p>
		
		<fieldset>
		<legend>JoinListServlet 을 GET 방식으로 요청</legend>
		<br>↓↓↓ CLICK ↓↓↓<br>
		<br> <input type="button" VALUE="LIST"
			onclick="location.href = 'list'" />
		</fieldset>
		
	</div>
</body>
</html>

joinWriter.jsp > doPOST

<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Join Form</title>
</head>
<body>
	<div align="center">
		<h1>Join Form</h1>
		<form action="insert" method="POST">
			<table>

				<tr>
					<td>ID</td>
					<td><input type="text" name="ID" required pattern="\w+" /></td>
				</tr>

				<tr>
					<td>PW</td>
					<td><input type="password" name="PW" required /></td>
				</tr>

				<tr>
					<td>e-mail</td>
					<td><input type="email" name="EMAIL" /></td>
				</tr>

				<tr>
					<td>Phone</td>
					<td><input type="text" name="PHONE" 	pattern="010-(\d{4}|\d{3})-\d{4}" /></td>
				</tr>

			</table>
			<p>

				<input type="submit" value="SAVE" /> &nbsp; 
				<input type="reset" value="CANCEL" onclick = "location.href = 'index.html'" />
		</form>

	</div>
</body>
</html>

joinInsertServlet.java

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;

import com.wjh.dao.JoinDAO;
import com.wjh.model.JoinModel;

@WebServlet("/insert")
public class joinInsert extends HttpServlet {
	private static final long serialVersionUID = 1L;
	
	// JoinDAO 객체 선언
	private JoinDAO JoinDAO = null;
	
    public joinInsert() {
        super();
    }

    /*
     *  @see GET 접근(가입하기 button → Join Form)
     */
	
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		RequestDispatcher request_dispatcher = request.getRequestDispatcher("joinWrite.jsp");
		request_dispatcher.forward(request, response);
		
	}

    
    /*
     * @see POST 접근 ()
     */
    
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		// POST 방식에서는 한글 parameter의 encoding이 깨짐
		// setCharacterEncoding으로 encoding 재설정
		request.setCharacterEncoding("UTF-8");
		
		String id = request.getParameter("ID");
		String pw = request.getParameter("PW");
		String email = request.getParameter("EMAIL");
		String phone = request.getParameter("PHONE");
				
		/*
		 * System.out.println("id___" + id);
		 * System.out.println("pw___" + pw);
		 * System.out.println("email___" + email);
		 * if(phone!=null){
		 * System.out.println("phone___" + phone+"\n");
		 * }
		 * 입력 값 없이 parameter만 넘어와도 null이 찍히지 않음 
		 */
		
		// JoinModel 객체 생성
		JoinModel model = new JoinModel();
		model.set_id(id);
		model.set_pw(pw);
		model.set_email(email);
		model.set_phone(phone);
		
		// JoinDAO 이용해 내용 입력
		this.JoinDAO = new JoinDAO();
		this.JoinDAO.insert(model);
		
		response.sendRedirect("index.html");
	}

}

joinList.java

package com.wjh.servlets;

import java.io.IOException;
import java.util.ArrayList;

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;

import com.wjh.dao.JoinDAO;
import com.wjh.model.JoinModel;

@WebServlet("/list")
public class joinList extends HttpServlet {
	private static final long serialVersionUID = 1L;

	// JoinDAO 객체 생성
	private JoinDAO joinDAO = null;
	
	public joinList() {
		super();
	}

	/*
	 * @see GET 접근 = joinList 화면 접근
	 */
	
	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		
		this.joinDAO = new JoinDAO();
		ArrayList<JoinModel> jl = this.joinDAO.select_all();
		
		/*
		System.out.println("Print JoinModel");
		for(JoinModel j : jl){
			System.out.println(j.get_num()+"\t"
									+j.get_id()+"\t"
									+j.get_pw()+"\t"
									+j.get_email()+"\t"
									+j.get_phone());
		}
		*/
		
          RequestDispatcher rd = request.getRequestDispatcher("joinList.jsp");
          request.setAttribute("list", jl);
          rd.forward(request, response);
          // RequestDispatcher 통해 jl 객체 전달
		
	}

	/*
	 * @see POST 접근 = 검색 조회 접근
	 */
	
	protected void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {


	}

}

joinList.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"	import = "java.util.ArrayList, com.wjh.model.JoinModel"%>

<%
	ArrayList<JoinModel> jl = (ArrayList<JoinModel>) request.getAttribute("list");
%>

<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>LIST</title>
</head>
<body>

	<div align="center">
		<h1>JOIN LIST</h1>

		<table border=1>
			<tr>
				<th>num</th>
				<th>id</th>
				<th>pw</th>
				<th>email</th>
				<th>phone</th>
			</tr>

<%
	for(JoinModel j : jl) {
%>
			<tr>
				<td><%=j.get_num() %></td>
				<td><%=j.get_id() %></td>
				<td><%=j.get_pw() %></td>
				<td><%=j.get_email() %></td>
				<td><%=j.get_phone() %></td>
			</tr>
<%
	}
%>
		</table>
		<p>

			<input type="button" value="HOME"
				onclick="location.href = 'index.html'" />
	</div>
</body>
</html>