Command 패턴

JSP

Command 패턴

승모근뭉치 2022. 12. 11. 10:40

[url-pattern]

- 디렉터리 패턴
   . 디렉토리 형태로 서버의 해당 컴포넌트를 찾아서 실행하는 패턴

   url-mapping servlet    url 맵핑
   http://localhost:8080/jsp_Ex_3/abc -------------> /abc 서블릿
   http://localhost:8080/jsp_Ex_3/ddd -------------> /ddd 서블릿
   디렉토리를 찾아가는 형태

- 확장자 패턴
   . 확장자 형태로 서버의 해당 컴포넌트를 찾아서 실행하는 패턴

   http://localhost:8080/jsp_Ex_2/aaa.do-----------> +----------+
    |*.do 서블릿 |
   http://localhost:8080/jsp_Ex_3/bbb.do-----------> +----------+

   do로끝나는 확장자 패턴이있으면 do가 있는 서블릿을 찾아간다.aaa.do도 bbb.do도
   *.do 서블릿을 찾아간다. 한놈을 찾아간다. 한곳에 모이는 거죠.aaa.do가 실행되면
   서블릿에서 내부적으로 어느곳에서 왔는지를 파악을 합니다. aaa.do에서 왔으면 내부적으로
   aaa.do에 맞는코드를 실행한다.

[FrontController 패턴]

  클라이언트 요청1 -------->  요청1 서블릿-------->
  클라이언트 요청2   ---------> 요청2 서블릿-------->
  클라이언트 요청3   ---------> 요청3 서블릿--------> DAO
  클라이언트 요청4   ---------> 요청4 서블릿-------->

  각각의 요청.각각의패턴이있다. 각 요청에 대한 해당 서블릿이 있다.
  각 서블릿에서 처리해줘야 될 것이 있다면
  위에 있는 거는 일반적인 방법:각 요청을 만들면 각 요청마다 중복되는 코드
  가 있어 비효율적이다.관리상 그렇게 좋은 패턴이 아니다.

  클라이언트 요청1-------->
  클라이언트 요청2-------->     모든 요청을 직접
  클라이언트 요청3-------->      처리하는 서블릿--------> DAO
  클라이언트 요청4-------->

[Command 패턴]
interface 구현
  클라이언트 요청1--------> ---> 요청1 클래스
  클라이언트 요청2-------->     모든 요청을 직접 ---> 요청2 클래스
  클라이언트 요청3-------->     처리하지 않는 서블릿 ---> 요청3 클래스    -----> DAO
  클라이언트 요청4-------->    ---> 요청4 클래스

studentAll.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
	<a href="studentAll.do"> 전체 학생 조회 </a>
</body>
</html>

FrontController.java

package com.test.ex;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.SQLException;
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;

/**
 * Servlet implementation class FrontController
 */
@WebServlet("*.do")
public class FrontController extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public FrontController() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		System.out.println("doGet");
		try {
			actionDo(request, response);			
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		System.out.println("doPost");
		try {
			actionDo(request, response);			
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}
	
	protected void actionDo(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException, SQLException {
		System.out.println("actionDo");
		
		String uri = request.getRequestURI();
		System.out.println("uri :" + uri);
		String conPath=request.getContextPath();
		System.out.println("conPath : "+ conPath);
		String command = uri.substring(conPath.length());
		System.out.println("command :"+command);
		
		String result = null;
		
		if(command.equals("/insert.do")) {
			System.out.println("insert");
			System.out.println("------------------");
			
		}else if(command.equals("/update.do")) {
			System.out.println("update");
			System.out.println("------------------");
			
		}else if(command.equals("/select.do")) {
			System.out.println("select");
			System.out.println("------------------");
		}else if(command.equals("/delete.do")) {
			System.out.println("delete");
			System.out.println("------------------");
		}else if(command.equals("/studentAll.do")) {
			System.out.println("스트던트올닷두");
			/*result = "/printStudent.jsp";
			
			RequestDispatcher dispatcher = request.getRequestDispatcher(result);
			dispatcher.forward(request, response);*/
			
			response.setContentType("text/html; charset=UTF-8");
			PrintWriter writer = response.getWriter();
			writer.println("<html><head></head><body>");
			
			Service svc = new StudentAllService();
			ArrayList<StudentDTO> sdtos = svc.execute(request, response);
			
			for(int i = 0; i < sdtos.size(); i++) {
				StudentDTO sdto = sdtos.get(i);
				String no = sdto.getHakbun();
				String pw = sdto.getPw();
				String name = sdto.getName();
				String hp = sdto.getHp();
				
				writer.println(no + "," + pw + "," + name + "," + hp + "<hr/>");
			}
			
			writer.println("</body></html>");
		}
	}
}

Service.java

package com.test.ex;

import java.sql.SQLException;
import java.util.ArrayList;

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

public interface Service {
	public ArrayList <StudentDTO> execute(HttpServletRequest request, HttpServletResponse response) throws SQLException;
}

StudentAllService.java

package com.test.ex;

import java.sql.SQLException;
import java.util.ArrayList;

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

public class StudentAllService implements Service {
	public StudentAllService() {
		
	}
	
	public ArrayList<StudentDTO> execute(HttpServletRequest request, HttpServletResponse response) throws SQLException {
		
		StudentDAO sdao = new StudentDAO();
		return sdao.select();
	}
}

StudentDAO.java

package com.test.ex;
import java.sql.*;
import java.util.*;
//DAO : DB에 접근하기위한 오브젝트(객체)
public class StudentDAO {
	Connection dbconn;
	PreparedStatement ps;
	ResultSet rs;
	String url ="jdbc:oracle:thin:@localhost:1521:orcl";
	String uid ="scott", pwd = "1234";
	
	public StudentDAO(){
		try {
			Class.forName("oracle.jdbc.driver.OracleDriver");
			dbconn = DriverManager.getConnection(url,uid,pwd);
			System.out.println("데이터베이스 연결!!");
		} catch (Exception e) {			
			e.printStackTrace();
		}
		
	}// 생성자
	
	
	public int insertStudent(StudentDTO sdto) throws SQLException{
		String hakbun = sdto.getHakbun();
		String pw = sdto.getPw();
		String name = sdto.getName();
		String hp = sdto.getHp();
		int n = this.insertStudent(hakbun, pw, name, hp);
		return n;
	}
	
	public int insertStudent(String hakbun, String pw, String name, String hp) 
			throws SQLException{
		try{
			String sql="insert into student values(?,?,?,?)";
			
			ps=dbconn.prepareStatement(sql);
			ps.setString(1, hakbun);
			ps.setString(2, pw);
			ps.setString(3, name);
			ps.setString(4, hp);
			
			int n = ps.executeUpdate();
			return n;
		}finally{
			if(ps !=null) ps.close();
			if(dbconn !=null) dbconn.close();
		}		
	}
	
	public ArrayList<StudentDTO> select() throws SQLException{
		
		ArrayList <StudentDTO> sdtos = new ArrayList<StudentDTO>();
		try{
			String sql = "select * from student";
			ps = dbconn.prepareStatement(sql);
			rs = ps.executeQuery();
			
			while(rs.next()) {
				StudentDTO sdto = new StudentDTO();
				sdto.setHakbun(rs.getString("no"));
				sdto.setPw(rs.getString("pw"));
				sdto.setName(rs.getString("name"));
				sdto.setHp(rs.getString("hp"));
				sdtos.add(sdto);
			}
		
		}finally{
			if(rs !=null) rs.close();
			if(ps !=null) ps.close();
			if(dbconn !=null) dbconn.close();
		}
		return sdtos;
	}
	
	public StudentDTO[] findSt(String name) throws SQLException{
		try{
			String sql="select * from student where name=?";
			ps=dbconn.prepareStatement(sql);
			ps.setString(1, name);
			rs = ps.executeQuery();	
			
			StudentDTO stArray[] = createArray(rs); 
			return stArray;
		}finally{
			if(rs !=null) rs.close();
			if(ps!=null) ps.close();
			if(dbconn !=null) dbconn.close();
		}
	}
	
	public StudentDTO[] createArray(ResultSet rs) throws SQLException{
		Vector<StudentDTO> v = new Vector<StudentDTO>();
		
		while(rs.next()){
			String hakbun=rs.getString(1);
			String pw = rs.getString(2);
			String name = rs.getString(3);
			String hp = rs.getString(4);
			
			StudentDTO rowSt = new StudentDTO(hakbun, pw, name, hp);
			v.add(rowSt);
		}//while End
		int vSize = v.size();
		StudentDTO stArray[] = new StudentDTO[vSize];
		v.copyInto(stArray); //벡터에 저장된 데이터를 stArray배열 객체에 복사
		return stArray;
	}
	
	public int delStudent(String name) throws SQLException{
		try{
			String sql="delete from student where name=?";
			ps=dbconn.prepareStatement(sql);
			ps.setString(1, name);
			int n = ps.executeUpdate();
			return n;
		}finally{
			if(ps !=null) ps.close();
			if(dbconn !=null) dbconn.close();
		}
	}
	
	
	
}

StudentDTO.java

package com.test.ex;

// Data Transfer Object (VO: Value Object)
public class StudentDTO {
	private String hakbun;
	private String pw;
	private String name;
	private String hp;
	
	public StudentDTO(){
		System.out.println("Student() 객체 생성");
	}
	public StudentDTO(String hakbun, String pw, String name, String hp){
		this.hakbun=hakbun;
		this.pw=pw;
		this.name=name;
		this.hp=hp;
	}
	
	//get 계열
	public String getHakbun() {		
		return hakbun;
	}
	public String getPw() {
		return pw;
	}
	public String getName() {
		return name;
	}
	public String getHp() {
		return hp;
	}

	//set 계열
	public void setHakbun(String hakbun) {
		System.out.println("setHakbun() :"+hakbun);
		this.hakbun = hakbun;
	}
	public void setPw(String pw) {
		System.out.println("setPw() :"+pw);
		this.pw = pw;
	}	
	public void setName(String name) {
		System.out.println("setName() :"+name);
		this.name = name;
	}
	public void setHp(String hp) {
		System.out.println("setHp() :"+hp);
		this.hp = hp;
	}	
	
}

printStudent.jsp

<%@page import="com.test.ex.StudentDTO"%>
<%@page import="java.util.ArrayList"%>
<%@page import="com.test.ex.StudentAllService"%>
<%@page import="com.test.ex.Service"%>
<%@page import="java.io.PrintWriter"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%
	response.setContentType("text/html; charset=UTF-8");

	PrintWriter writer = response.getWriter();
	writer.println("<html><head></head><body>");
	
	Service svc = new StudentAllService();
	ArrayList<StudentDTO> sdtos = svc.execute(request, response);
	
	for(int i = 0; i < sdtos.size(); i++) {
		StudentDTO sdto = sdtos.get(i);
		String no = sdto.getHakbun();
		String pw = sdto.getPw();
		String name = sdto.getName();
		String hp = sdto.getHp();
		
		writer.println(no + "," + pw + "," + name + "," + hp + "<hr/>");
	}
	
	writer.println("</body></html>");
%>
<!-- <!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>

</body>
</html> -->