[JSP Practice] - JSP properties 파일 로드

#JSP properties 파일 로드

 

 

1.dao클래스 만들 때
-cmd에서 dao객체를 사용하기 때문에 상위 타입을 가지고 다형성을 활용해야합니다.
-CMDFactory 클래스들을 -> properties로 관리합니다.

#사이드 이펙트
-의존성을 최소화합니다.

 

#요즘 DTO추세
-자바 빈을 안 만들고 map을 사용합니다.
-List<Map<String, Object>

 

#DBCP
-데이터베이스 커넥션 풀입니다.

 

1. GuestBook

package org.smart.bean;

import java.text.SimpleDateFormat;
import java.util.Date;

public class GuestBook {
	private String gid;
	private String content;
	private String reg;
	
	public GuestBook() {
		SimpleDateFormat sdf = 
				new SimpleDateFormat("yyyy.MM.dd(kk:mm)");
		reg = sdf.format(new Date());
	}

	public GuestBook(String content) {
		this();
		setContent(content);
	}

	public GuestBook(String gid, String content, String reg) {
		this.gid = gid;
		this.content = content;
		this.reg = reg;
	}

	public String getGid() {
		return gid;
	}

	public void setGid(String gid) {
		this.gid = gid;
	}

	public String getContent() {
		return content;
	}

	public void setContent(String content) {
		this.content = content;
	}

	public String getReg() {
		return reg;
	}

	public void setReg(String reg) {
		this.reg = reg;
	}
	
	
}

 

2. ICMD

package org.smart.cmd;

import javax.servlet.http.HttpServletRequest;

public interface ICMD {
	String action(HttpServletRequest request);
}

 

3. ReadCmd

package org.smart.cmd;

import java.sql.Connection;

import javax.servlet.http.HttpServletRequest;

import org.smart.bean.GuestBook;
import org.smart.dao.DAOFactory;
import org.smart.dao.IDAO;

public class ReadCmd implements ICMD{

	@Override
	public String action(HttpServletRequest request) {
		// dao가 Oracle일수도 있고 MySQL일수도 있다.
		
		IDAO dao = DAOFactory.getDao();
		Connection con = dao.connect();
		GuestBook[] books = dao.readBook(con);
		dao.disconnect(con);
		request.setAttribute("books", books);
		
		return "main.jsp";
	}
	
}

 

4. WriteCmd

package org.smart.cmd;

import java.sql.Connection;

import javax.servlet.http.HttpServletRequest;

import org.smart.bean.GuestBook;
import org.smart.dao.DAOFactory;
import org.smart.dao.IDAO;

public class WriteCmd implements ICMD{
	
	
	// 리턴타입이 void에서 String으로 바뀜(돌아 갈 경로)
	@Override
	public String action(HttpServletRequest request) {
		
		String content = request.getParameter("content");
		GuestBook book = new GuestBook(content);
		
		IDAO dao = DAOFactory.getDao();
		Connection con = dao.connect(); 
		dao.write(con, book);
		dao.disconnect(con);
		request.setAttribute("isRedirect", true);
		
		return request.getContextPath();
	}

}

 

5. CMDFactory

package org.smart.control;

import java.util.Hashtable;
import java.util.Properties;
import java.util.Set;

import javax.servlet.http.HttpServletRequest;

import org.smart.cmd.ICMD;import com.sun.xml.internal.ws.resources.HttpserverMessages;

public class CMDFactory {
	private static Hashtable<String, ICMD> cmds = new Hashtable<String, ICMD>();
	
	public static void initCmds(Properties prop) {
		try {
			// cmdsInfo.properties의 키값 *.do 를 가져옴
			// ? <- 아무값이나 다 받을 수 있다.
			Set<?> keys = prop.keySet();
			// Object타입 = ?사용, 
			for (Object keyObj : keys) {
				// 
				String key = keyObj.toString();
				// 키 값 에서 value값 가져옴 (org.smart.cmd.ReadCmd)
				String className = prop.getProperty(key);
				// org.smart.cmd.ReadCmd 읽어서 클래스의 정보를 읽어옴
				// newInstance() -> 해당 클래스(불러온 className)의 객체를 생성 할 수있다.
				// (new className)과 같은 의미 (class이름이 문자열이라 new로는 할 수가 없다.)
				// 이렇게 생성시 Object타입으로 넘어와서 ICMD로 받는다.
				// 문제점 : 리플렉션를 하면 private도 다 접근되어서 객체지향의 본질을 파괴 할 수도 있다.
				// private 사용이 class명.setAccessible(true)를 하면 사용가능
				ICMD cmdObj = (ICMD)Class.forName(className).newInstance();
				cmds.put(key, cmdObj);
			} 
		} catch (InstantiationException e) {
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			e.printStackTrace(); 
		} catch (ClassNotFoundException e) { 
			e.printStackTrace();
		}
	}
	 
	public static String doAction(HttpServletRequest request, String key){
		return cmds.get(key).action(request);
	}
}

 

6. MainServlet

package org.smart.control;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Properties;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.smart.dao.DAOFactory;

public class MainServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;

	private void loadProp(String path, Properties prop) {
		FileInputStream fis = null;
		try {
			fis = new FileInputStream(path);
			prop.load(fis);
		
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} finally{
			try {
				fis.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}

	@Override
	public void init(ServletConfig config) throws ServletException {
		super.init(config);
		// 어플리케이션을 얻어옴 
		ServletContext application =
				config.getServletContext();
		// web.xml에 경로만 따로 빼서 처리
		String path =
			config.getInitParameter("cmdsInfoPath");
		
		String realPath = application.getRealPath(path);
		
		Properties prop = new Properties();
		loadProp(realPath, prop);  
		
		CMDFactory.initCmds(prop); 
		
		path = config.getInitParameter("dbTypePath");
		
		realPath =
				application.getRealPath(path);
		prop = new Properties();
		
		loadProp(realPath, prop); 
		DAOFactory.initDaos(prop.getProperty("dbms"));
	}

	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doAction(request, response);
	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doAction(request, response);
	}
	
	private void doAction(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		request.setCharacterEncoding("euc_kr");
		// uri마다 다르게 반응
		String uri = request.getRequestURI(); 
		System.out.println("uri: " +uri); 
		
		String contextPath = request.getContextPath();
		System.out.println("contextPath: " + contextPath);
		// uri 
		String what = uri.substring(request.getContextPath().length());
		System.out.println("what: " + what);
		
		String nextPage = CMDFactory.doAction(request, what);
		
		if(request.getAttribute("isRedirect") == null){
			RequestDispatcher rd = request.getRequestDispatcher(nextPage);
			rd.forward(request, response);
		}else{
			response.sendRedirect(nextPage);
		}
	}

}

 

7. DAOFactory

package org.smart.dao;

import java.util.Hashtable;

public class DAOFactory {
	private static Hashtable<String, IDAO> daos = 
			new Hashtable<String, IDAO>();
	
	private static String dbms;
	
	// mysql, oracle 선택
	// dao가 바뀌어도 관련된 cmd들을 바꿀 필요가 없다.
	// 목적 : 둘 중 뭐가 선택되든 앞에 cmd클래스들이 바뀌면 안된다.
	public static void initDaos(String inputDbms){
		dbms = inputDbms;
		daos.put("mysql", MySQLGuestBookDAO.getInstance());
		daos.put("oracle", new OracleGuestBookDAO());
	}
	
	public static IDAO getDao(){
		return daos.get(dbms);
	}
}

 

8. IDAO

package org.smart.dao;

import java.sql.Connection;

import org.smart.bean.GuestBook;

public interface IDAO {
	// DAO의 규칙
	Connection connect();
	int write(Connection con, GuestBook book);
	GuestBook[] readBook(Connection con);
	void disconnect(Connection con);  
}

 

9. MySQLConstant

package org.smart.dao;

public interface MySQLConstant {
	String DRIVER = "com.mysql.jdbc.Driver";
	
	String DB_URL = "jdbc:mysql://localhost:3306/test";
	String UID = "root";
	String UPW = "1234";
	
	String WRITE = "INSERT INTO guest_book (content, reg) " +
			"VALUES(?,?)";
	String READ_BOOK =
			"SELECT * FROM guest_book ORDER BY gid DESC";
}

 

10. MySQLGuestBookDAO

package org.smart.dao;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Vector;

import org.smart.bean.GuestBook;

public class MySQLGuestBookDAO implements IDAO, MySQLConstant{
	private static MySQLGuestBookDAO instance = new MySQLGuestBookDAO();

	private MySQLGuestBookDAO(){
		try {
			Class.forName(DRIVER);
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}
	}

	
	public static MySQLGuestBookDAO getInstance(){
		return instance;
	}
	
	@Override
	public Connection connect() {
		Connection con = null;
		
		try {
			con = DriverManager.getConnection(DB_URL, UID, UPW);
		} catch (SQLException e) {
			e.printStackTrace();
		}
		
		return con;
	}

	@Override
	public int write(Connection con, GuestBook book) {
		int result = 0;
		PreparedStatement pStmt = null;
		
		try {
			pStmt = con.prepareStatement(WRITE);
			pStmt.setString(1, book.getContent());
			pStmt.setString(2, book.getReg());
			
			result = pStmt.executeUpdate();
		} catch (Exception e) {
			e.printStackTrace();
		} finally{
			closeAll(pStmt);
		}
		
		return result;
	}

	@Override
	public GuestBook[] readBook(Connection con) {
		GuestBook[] books = null;
		
		PreparedStatement pStmt = null;
		ResultSet rs = null;
		
		try {
			pStmt = con.prepareStatement(READ_BOOK);
			rs = pStmt.executeQuery();
			
			Vector<GuestBook> vector = new Vector<GuestBook>();
			
			while(rs.next()){
				GuestBook book = new GuestBook(
					rs.getString("gid"),
					rs.getString("content"),
					rs.getString("reg")
				);
				vector.add(book);
			}
			books = vector.toArray(new GuestBook[0]);
		} catch (Exception e) {
			e.printStackTrace();
		} finally{
			closeAll(rs);
			closeAll(pStmt);
		}
		
		return books;
	}

	@Override
	public void disconnect(Connection con) {
			try {
				if(con != null)con.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
	}
	
	private void closeAll(PreparedStatement pStmt){
			try {
				if(pStmt != null)pStmt.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
	}
	
	private void closeAll(ResultSet rs){
			try {
				if(rs != null)rs.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
	}
	
	
}

 

11. OracleGuestBookDAO

package org.smart.dao;

import java.sql.Connection;

import org.smart.bean.GuestBook;

public class OracleGuestBookDAO implements IDAO{

	@Override
	public Connection connect() {
		return null;
	}

	@Override
	public int write(Connection con, GuestBook book) {
		return 0;
	}

	@Override
	public GuestBook[] readBook(Connection con) {
		return null;
	}

	@Override
	public void disconnect(Connection con) {
		
	}
	
}

 

12. cmdsInfo.properties

/start.do=org.smart.cmd.ReadCmd
/write.do=org.smart.cmd.WriteCmd

 

13. dbtype.properties

dbms=mysql

 

14. web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>guestBook_prop</display-name>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
  <servlet>
    <description></description>
    <display-name>MainServlet</display-name>
    <servlet-name>MainServlet</servlet-name>
    <servlet-class>org.smart.control.MainServlet</servlet-class>
    
     <init-param> 
    	<param-name>dbTypePath</param-name>
    	<param-value>/WEB-INF/dbtype.properties</param-value>
    </init-param>
    
    <init-param> 
    	<param-name>cmdsInfoPath</param-name>
    	<param-value>/WEB-INF/cmdsInfo.properties</param-value>
    </init-param>
     
    <load-on-startup>0</load-on-startup>
  </servlet>
  
  <servlet-mapping>  
    <servlet-name>MainServlet</servlet-name>
    <url-pattern>*.do</url-pattern> 
  </servlet-mapping>
  
</web-app>      

 

15. index.jsp

<%@ page language="java" contentType="text/html; charset=EUC-KR"
    pageEncoding="EUC-KR"%>
<jsp:forward page="start.do" />

 

16. main.jsp

<%@ page language="java" contentType="text/html; charset=EUC-KR"
    pageEncoding="EUC-KR"%>
<%@ page import="org.smart.bean.GuestBook" %>    
<!DOCTYPE html>
<html> 
<head>
<meta http-equiv="Content-Type" content="text/html; charset=EUC-KR">
<title>main.jsp</title>
</head>
<body>
 	<form action="write.do" method="post">
 		<input type="text" name="content" />
 		<input type="submit" value="글쓰기" />
 		<input type="reset" value="취소" />
 	</form>
 	<hr/>
 	<table>
 		<tr>
 			<th>번호</th>
 			<th>내용</th>
 			<th>작성일</th>
 		</tr>
 		<%
 			GuestBook[] books = (GuestBook[])request.getAttribute("books");
 			if(books.length == 0){
 		%>
 		<tr>
 			<td colspan="3">Empty</td>
 		</tr>
 		<%
 			}else{
				for(GuestBook book : books){ 				
 		%>
 		<tr>
 			<td><%=book.getGid() %></td>
 			<td><%=book.getContent() %></td>
 			<td><%=book.getReg() %></td>
 		</tr>
 		<%
				}
 			}
 		%>
 	</table>
</body>
</html>