JSP 프로그래밍 - [Servlet] Servlet(서블릿) (2)

Q. URL vs URI 의 차이?

URL은 프로토콜(http,https)부터 servlet 파일까지의 경로를 말한다.
(예: http://localhost:8181/webTesting/com/java/servlet/Example06)

URI는 해당 context(프로젝트명)부터 시작해서 servlet파일까지의 경로를 말한다.
(예: /webTesting/com/java/servlet/Example06)

 

 

URL, URI, contextPath, servletPath 4가지 꼭 기억하기!!

 

URL : 프로토콜부터 서블릿 파일까지 경로

URI :  컨텍스트(프로젝트명)부터 서블릿 파일까지의 경루

contextPath :  프로젝트 경로

servletPath : 현재 서블릿의 풀 패키지명

 

Example06.java

package com.java.servlet;

import java.io.IOException;
import java.util.Enumeration;

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 Example06
 */
public class Example06 extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public Example06() {
        super();
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		/* request 객체 역할 - 사용자 요청
		 * 한글 Encoding 기능
		 * 파라미터 읽기 기능
		 * 서버와 관련된 정보 읽기 기능
		 * 웹브라우저 관련 정보 읽기 기능
		 * 헤더 읽기 기능
		 * 쿠키 읽기 기능
		 * 속성처리 기능
		 * response 객체 
		 * */
		
		//한글설정
		request.setCharacterEncoding("utf-8");
		
		//파라미터 읽기
		int su = Integer.parseInt(request.getParameter("su"));
		System.out.println(su);
		
		//서버와 관련된 정보 읽기 기능
		String serverName = request.getServerName();
		int serverPort = request.getServerPort();
		
		// Uniform Resource Location 
		// :프로토콜(http,https)부터 servlet 파일까지의 경로를 말한다.
		// http://localhost:8181/webTesting/com/java/servlet/Example06
		StringBuffer URL = request.getRequestURL();	
		
		// Uniform Resource Identifier
		// :해당 context(프로젝트명)부터 시작해서 servlet파일까지의 경로를 말한다.
		// /webTesting/com/java/servlet/Example06
		String URI = request.getRequestURI();  
		
		// /webTesting
		String contextPath = request.getContextPath();
		// /com/java/servlet/Example06
		String servletPath = request.getServletPath();
		
		
		System.out.println("서버이름:" + serverName);
		System.out.println("서버포트:" + serverPort);
		
		System.out.println("URL" + URL);
		System.out.println("URI" + URI);
		
		System.out.println("컨텍스트(프로젝트명) 경로:" + contextPath);
		System.out.println("서블릿 경로:" + servletPath);
		System.out.println("요청방식:" + request.getMethod());
		
		// 클라이언트 정보 및 웹브라우저 관련 정보 읽기 기능
		System.out.println("요청프로토몰:" +request.getProtocol());
		System.out.println("클라이언트 주소:" + request.getRemoteAddr());
		System.out.println("클라이언트 포트:" +request.getRemotePort());
		
		// 헤더 읽기 기능
		Enumeration<String> header = request.getHeaderNames();
		while(header.hasMoreElements()) {
			String key = header.nextElement();
			String value = request.getHeader(key);
			System.out.println(key + ":\t" + value);
		}
		// 쿠키 읽기 기능 - 쿠키 저장 Response
		// 속성처리 기능

	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}

}

 

 

 

 

 

 

 

 

---

/* response 객체
 * 문서타입, 한글 : setContextType 설정
 * 출력 : getWriter()
 * 쿠키 저장(설정) 기능, 헤더 설정(파일업로드 시) 기능
 * 페이지 이동: sendRedirect
 * */

 

 

Example07_Sucess.java

package com.java.servlet;

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

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 Example07_Success
 */

public class Example07_Success extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public Example07_Success() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		System.out.println("성공");
		
		response.setContentType("text/html;charset=utf-8");
		PrintWriter out = response.getWriter();
		out.print("<html>");
		out.print("<head><title>로그인</title></head>");
		out.print("<body>");
		out.print("<h3>방문을 환영합니다.</h3>");
		out.print("</body>");
		out.print("<html>");
		out.close();
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}

 

 

 

Example07_Fail.java

package com.java.servlet;

import java.io.IOException;
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 Example07_Fail
 */

public class Example07_Fail extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public Example07_Fail() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		System.out.println("실패");
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}

 

 

 

07_Example.html

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
   <form action="http://localhost:8181/webTesting/com/java/servlet/Example07" method="post">
 	<label>아이디</label>
	<input type="text" name="id"/>
	<br /><br />
	
	<label>비밀번호</label>
	<input type="text" name="pw"/>
	<br /><br />
   
   	<input type="submit" value="전송"/>
	<input type="reset" value="취소" />
   </form>
</body>
</html>