은성이의 프로그램X파일

package member.dto;

public class MemberDTO {
 private String id;
 private String password;
 private String name;
 private String registerNumber;
 private int mileage;
 public MemberDTO() {
  super();
 }
 public MemberDTO(String id, String password, String name,
   String registerNumber, int mileage) {
  super();
  this.id = id;
  this.password = password;
  this.name = name;
  this.registerNumber = registerNumber;
  this.mileage = mileage;
 }
 public String getId() {
  return id;
 }
 public void setId(String id) {
  this.id = id;
 }
 public String getPassword() {
  return password;
 }
 public void setPassword(String password) {
  this.password = password;
 }
 public String getName() {
  return name;
 }
 public void setName(String name) {
  this.name = name;
 }
 public String getRegisterNumber() {
  return registerNumber;
 }
 public void setRegisterNumber(String registerNumber) {
  this.registerNumber = registerNumber;
 }
 public int getMileage() {
  return mileage;
 }
 public void setMileage(int mileage) {
  this.mileage = mileage;
 }
 @Override
 public String toString() {
  return "MemberDTO [id=" + id + ", password=" + password + ", name="
    + name + ", registerNumber=" + registerNumber + ", mileage="
    + mileage + "]";
 }
 @Override
 public int hashCode() {
  final int prime = 31;
  int result = 1;
  result = prime * result + ((id == null) ? 0 : id.hashCode());
  result = prime * result + mileage;
  result = prime * result + ((name == null) ? 0 : name.hashCode());
  result = prime * result
    + ((password == null) ? 0 : password.hashCode());
  result = prime * result
    + ((registerNumber == null) ? 0 : registerNumber.hashCode());
  return result;
 }
 @Override
 public boolean equals(Object obj) {
  if (this == obj)
   return true;
  if (obj == null)
   return false;
  if (getClass() != obj.getClass())
   return false;
  MemberDTO other = (MemberDTO) obj;
  if (id == null) {
   if (other.id != null)
    return false;
  } else if (!id.equals(other.id))
   return false;
  if (mileage != other.mileage)
   return false;
  if (name == null) {
   if (other.name != null)
    return false;
  } else if (!name.equals(other.name))
   return false;
  if (password == null) {
   if (other.password != null)
    return false;
  } else if (!password.equals(other.password))
   return false;
  if (registerNumber == null) {
   if (other.registerNumber != null)
    return false;
  } else if (!registerNumber.equals(other.registerNumber))
   return false;
  return true;
 }
 
}

package member.listener;

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

public class DriverLoadingListener implements ServletContextListener {

    public DriverLoadingListener() {
    
    }

    public void contextInitialized(ServletContextEvent arg0) {
      //web.xml에 있는 Context읽어오기(초기 파라미터)
      ServletContext ctx = arg0.getServletContext();
      //web.xml에 있는 driver class 읽어오기
      String driverClass = ctx.getInitParameter("driver class");
       try {
        //어플리케이션이 시작할 때 driver class 로딩
   Class.forName(driverClass);
   System.out.println("-----Driver Loading 성공------");
  } catch (Exception e) {
  }
    }

    public void contextDestroyed(ServletContextEvent arg0) {
       
    }
 
}

<?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" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" 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>member_servlet</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <context-param>
   <param-name>driver class</param-name>
   <param-value>oracle.jdbc.driver.OracleDriver</param-value>
  </context-param>
  <context-param>
   <param-name>url</param-name>
   <param-value>jdbc:oracleLthinL@127.0.0.1:1521:XE</param-value>
  </context-param>
  <context-param>
   <param-name>user</param-name>
   <param-value>scott</param-value>
  </context-param>
  <context-param>
   <param-name>password</param-name>
   <param-value>tiger</param-value>
  </context-param>
 
  <listener>
    <listener-class>member.listener.DriverLoadingListener</listener-class>
  </listener>
</web-app>

package servlet.session;

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

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

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

    public WriteServlet() {
        super();
    }
 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  doPost(request,response);
 }

 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  //클라이언트 별로 저장 하는 곳을 분리하고 싶을 때 세션스코프를 사용한다.
  //어플리케이션 스코프를 사용하면 하나의 저장공간에 저장이 되어, c1,c2의 클라이언트가 값을 넣으면 두 군데가 같은 결과가 나오고
  //리퀘스트 스코프로 하게 되면 응답을 하고 나면 저장 공간이 사라져서 값을 받아 올수가 없다.
  request.setCharacterEncoding("utf-8");
  String text = request.getParameter("text");
  //text를 session scope에 설정
  HttpSession session = request.getSession();
  
  //같은 타입의 데이터를 들어 오는 만큼 넣어 줄 것이기 때문에 ArrayList를 사용한다. (ArrayList를 사용안하면 먼저 들어온 값은 사라진다.)
  //기존의 list가 있으면 list값을 받아오고 없다면 새로 생성해서 값을 넣어 줘라.
  ArrayList list = (ArrayList)session.getAttribute("list");
  if(list==null){
   list = new ArrayList();
   session.setAttribute("list", list);
  }
  list.add(text);
  response.sendRedirect("/myweb/session/write_form.html");
 }

}

package servlet.session;

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

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

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

    public ShowServlet() {
        super();
       
    }

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

 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  //Session scope에 지금까지 저장된 클라이언트가 보낸 text들을 출력
  HttpSession session = request.getSession();
  String url = null;
  ArrayList list = (ArrayList)session.getAttribute("list");
  //출력
  response.setContentType("text/html;charset=utf-8");
  PrintWriter out = response.getWriter();
  out.println("<html><body>");
  out.println("지금까지 입력된 값<br>");
  for(int i=0;i<list.size();i++){
   out.println((i+1)+" : "+list.get(i)+"<br>");
  }
  out.println("</body></html>");
 }

}

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="/myweb/session_write" method="post">
<input type="text" name="text" size="50">
<input type="submit" value="글전송">
<p>
<a href="/myweb/session_show">입력한 글들 출력</a>
</form>
</body>
</html>

package servlet.session;

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

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

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

    public ShowServlet() {
        super();
       
    }

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

 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  //Session scope에 지금까지 저장된 클라이언트가 보낸 text들을 출력
  HttpSession session = request.getSession();
  String url = null;
  ArrayList list = (ArrayList)session.getAttribute("list");
  //출력
  response.setContentType("text/html;charset=utf-8");
  PrintWriter out = response.getWriter();
  out.println("<html><body>");
  String jSessionID = session.getId();
  out.println("JSESSIONID : "+jSessionID+"<br>");
  
  out.println("지금까지 입력된 값<br>");
  for(int i=0;i<list.size();i++){
   out.println((i+1)+" : "+list.get(i)+"<br>");
  }
  out.println("</body></html>");
 }

}

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="/myweb/session_write" method="post">
<input type="text" name="text" size="50">
<input type="submit" value="글전송">
<p>
<a href="/myweb/session_show">입력한 글들 출력</a>
</form>
</body>
</html>

package servlet.session;

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

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

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

    public WriteServlet() {
        super();
    }
 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  doPost(request,response);
 }

 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  //클라이언트 별로 저장 하는 곳을 분리하고 싶을 때 세션스코프를 사용한다.
  //어플리케이션 스코프를 사용하면 하나의 저장공간에 저장이 되어, c1,c2의 클라이언트가 값을 넣으면 두 군데가 같은 결과가 나오고
  //리퀘스트 스코프로 하게 되면 응답을 하고 나면 저장 공간이 사라져서 값을 받아 올수가 없다.
  request.setCharacterEncoding("utf-8");
  String text = request.getParameter("text");
  //text를 session scope에 설정
  HttpSession session = request.getSession();
  //session.setAttribute("text", text); // (ArrayList를 사용안하면 먼저 들어온 값은 사라진다.)
  //같은 타입의 데이터를 들어 오는 만큼 넣어 줄 것이기 때문에 ArrayList를 사용한다.
  //기존의 list가 있으면 list값을 받아오고 없다면 새로 생성해서 값을 넣어 줘라.
  ArrayList list = (ArrayList)session.getAttribute("list");
  if(list==null){
   list = new ArrayList();
   session.setAttribute("list", list);
  }
  list.add(text);
  response.sendRedirect("/myweb/session/write_form.html");
 }

}

package servlet.session;

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

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

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

    public ShowServlet() {
        super();
       
    }

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

 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  //Session scope에 지금까지 저장된 클라이언트가 보낸 text들을 출력
  HttpSession session = request.getSession();
  String url = null;
  ArrayList list = (ArrayList)session.getAttribute("list");
  if(list==null){
   response.sendRedirect("/myweb/session/write_form.html");
   return;
  }
  //출력
  response.setContentType("text/html;charset=utf-8");
  PrintWriter out = response.getWriter();
  out.println("<html><body>");
  String jSessionID = session.getId();
  out.println("JSESSIONID : "+jSessionID+"<br>");
  
  out.println("지금까지 입력된 값<br>");
  for(int i=0;i<list.size();i++){
   out.println((i+1)+" : "+list.get(i)+"<br>");
  }
  out.println("<p><a href='/myweb/session_remove'>모든 입력글 삭제</a>");
  out.println("</body></html>");
 }

}

package servlet.session;

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

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * Servlet implementation class RemoveServlet
 */
public class RemoveServlet extends HttpServlet {
 private static final long serialVersionUID = 1L;

    public RemoveServlet() {
        super();
      
    }

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

 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  //Session scope의 list 삭제
  HttpSession session = request.getSession();
  session.removeAttribute("list");
  response.setContentType("text/html;charset=utf-8");
  PrintWriter out = response.getWriter();
  out.println("<html><body>");
  out.println("<a href='/myweb/session/write_form.html'>폼가기</a><br>");
  out.println("<p><a href='/myweb/session_show'>입력한 글 보기</a>");
  out.println("</body></html>");
 }

}

package servlet.cookie;

import java.io.IOException;
import java.net.URLEncoder;

import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.tomcat.util.http.Cookies;

public class SetCookieServlet2 extends HttpServlet {
 private static final long serialVersionUID = 1L;

    public SetCookieServlet2() {
        super();
    }

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

 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  //Cookie값에 한글이 들어간 경우 encoding처리가 필요
  //java.net.URLEncoder.encode()
  String name = URLEncoder.encode("홍길동"); //한글을 encode
  String address = URLEncoder.encode("서울시 가락동"); //두개의 쿠기값 사용
  Cookie c1 = new Cookie("name",name);
  Cookie c2 = new Cookie("address",address);
  
  //client로 전송
  response.addCookie(c1);
  response.addCookie(c2);
  //응답
  response.sendRedirect("/myweb/cookie/req.html");
  
  
 }

}

package servlet.cookie;

import java.io.IOException;
import java.io.PrintWriter;
import java.net.URLDecoder;

import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

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

    public GetCookieServlet() {
        super();
      
    }

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

 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  // SetCookieServlet에서 설정한 쿠키 값을 조회하여 출력
  // 1. 쿠키 조회
  Cookie[] cs = request.getCookies();
  // 2. 출력
  response.setContentType("text/html;charset=utf-8");
  PrintWriter out = response.getWriter();
  out.println("<html><body>");
  for(Cookie c : cs){
   String name = c.getName();
   String value = c.getValue();
   if(name.equals("name") || name.equals("address")){
    value = URLDecoder.decode(value);
   }
   out.println(name + " - "+ value+"<br>");
  }

  out.println("</body></html>");
  
  //name="name"인 값만 뽑아 내기
  out.println("<hr>");
  String value=null;
  for(int i=0;i<cs.length;i++){
   if(cs[i].getName().equals("name")){
    value = cs[i].getValue();
   }
  }
  if(value!=null){
   out.println(URLDecoder.decode(value)+"님 환영합니다.");
  }else{
   out.println("이름이 없습니다.");
  }
 }

}
 

package servlet.cookie;

import java.io.IOException;
import java.io.PrintWriter;
import java.text.SimpleDateFormat;
import java.util.Date;

import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class SetCookieServlet1 extends HttpServlet {
 private static final long serialVersionUID = 1L;

    public SetCookieServlet1() {
        super();
      
    }

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

 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  //현재 시간을 쿠키정보로 만들어 클라이언트에 전송
  //현재 시간 조회
  Date date = new Date();
  //날짜 포멧전환, E : 요일
  SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd  HH:mm:ss");
  String nowDate = sdf.format(date);
  
  Cookie c = new Cookie("nowDate",nowDate); //쿠키값 1개 생성
  response.addCookie(c); //쿠키 정보를 client로 전송
  //응답처리
  response.setContentType("text/html;charset=utf-8");
  PrintWriter out = response.getWriter();
  out.println("<html><body>");
  out.println("현재 일시 : "+nowDate);
  out.println("<br><a href='/myweb/getcookie'>Get Cookie요청</a>");
  out.println("</body></html>");
 }

}

package servlet.cookie;

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

import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

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

    public GetCookieServlet() {
        super();
      
    }

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

 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  // SetCookieServlet에서 설정한 쿠키 값을 조회하여 출력
  // 1. 쿠키 조회
  Cookie[] cs = request.getCookies();
  // 2. 출력
  response.setContentType("text/html;charset=utf-8");
  PrintWriter out = response.getWriter();
  out.println("<html><body>");
  for(Cookie c : cs){
   out.println("쿠키 이름 : "+c.getName()); 
   out.println("쿠키 값 : "+c.getValue()+"<br>");
  }

  out.println("</body></html>");
  
 }

}

/*package servlet.lifecycle;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;

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

public class CounterServlet extends HttpServlet{
 //변수 저장하는 방법(변수, 파일, DB 세가지 방법이 있다.)
 private int visitCount;
 //카운트 한 값을 저장 시킬 공간
 private String counterFile = "F:\\apache-tomcat-6.0.35\\counter.txt";
 //생성자( 객체 생성)
 public CounterServlet(){
  
 }
 //객체 생성 직후 실행(count값 read 한 다음에 visitCount로 넣기)
 public void init(){
 
  FileReader fileReader = null;
  BufferedReader bufferedReader = null;
  try {
   fileReader = new FileReader(counterFile);
   bufferedReader = new BufferedReader(fileReader);
   String readCount = bufferedReader.readLine();
   visitCount = Integer.parseInt(readCount);
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  } finally{
   if(bufferedReader!=null){
    try {
     bufferedReader.close();
    } catch (IOException e) {
     e.printStackTrace();
    }
   }
   
  }
  
 }
 //객체 소멸 직전 실행(visitCount 값을 파일로 write)
 public void destroy(){
  FileWriter fileWriter = null;
  PrintWriter printWriter = null;
  File file = null;
  try {
   fileWriter = new FileWriter(counterFile);

   printWriter = new PrintWriter(fileWriter,true);
   printWriter.println(visitCount);
  } catch (IOException e) {
   e.printStackTrace();
  } finally{
   printWriter.close();
  }
 }
 //service() -> doGet() : 클라이언트 요청이 들어올때 마다 호출
 public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException{
  response.setContentType("text/html;charset=UTF-8");
  PrintWriter out = response.getWriter();
  out.println("<html><head><title>카운터</title></head>");
  out.println("<body>");
  visitCount++;//카운터의 값을 1증가
  out.println("당신은 "+visitCount+" 번째 방문자 입니다.");
  out.println("</body></html>");
 }
}
*/

package servlet.lifecycle;

 
import java.io.DataInputStream;
import java.io.DataOutputStream;
 
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
 
import java.io.IOException;
import java.io.PrintWriter;

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

public class CounterServlet extends HttpServlet{
 //변수 저장하는 방법(변수, 파일, DB 세가지 방법이 있다.)
 private int visitCount;
 //카운트 한 값을 저장 시킬 공간
 //private String counterFile = "F:\\apache-tomcat-6.0.35\\counter.dat";
 private String counterFile;
 //생성자( 객체 생성)
 public CounterServlet(){
  
 }
 //객체 생성 직후 실행(count값 read 한 다음에 visitCount로 넣기)
 public void init(){
  System.out.println("counterFile : "+counterFile);
  ServletConfig conf = getServletConfig();
  counterFile = conf.getInitParameter("saveFile");
  System.out.println("counterFile : "+counterFile);
  DataInputStream dataInputStream = null;
  try {
   dataInputStream = new DataInputStream(new FileInputStream(counterFile));
   visitCount = dataInputStream.readInt();
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  } finally{
   if(dataInputStream!=null){
    try {
     dataInputStream.close();
    } catch (IOException e) {
     e.printStackTrace();
    }
   }
  }
  
 }
 //객체 소멸 직전 실행(visitCount 값을 파일로 write)
 public void destroy(){
  DataOutputStream dataOutputStream = null;
  try {
   dataOutputStream = new DataOutputStream(new FileOutputStream(counterFile));
   dataOutputStream.writeInt(visitCount);
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  } finally{
   if( dataOutputStream!=null){
    try {
     dataOutputStream.close();
    } catch (IOException e) {
     e.printStackTrace();
    }
   }
  }
 }
 //service() -> doGet() : 클라이언트 요청이 들어올때 마다 호출
 public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException{
  response.setContentType("text/html;charset=UTF-8");
  PrintWriter out = response.getWriter();
  out.println("<html><head><title>카운터</title></head>");
  out.println("<body>");
  synchronized(this){
   visitCount++;//카운터의 값을 1증가
   try{
    Thread.sleep(5000);
    
   }catch(Exception e){
    
   }
  
  out.println("당신은 "+visitCount+" 번째 방문자 입니다.");
  }
  out.println("</body></html>");
 }
}

/*package servlet.lifecycle;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;

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

public class CounterServlet extends HttpServlet{
 //변수 저장하는 방법(변수, 파일, DB 세가지 방법이 있다.)
 private int visitCount;
 //카운트 한 값을 저장 시킬 공간
 private String counterFile = "F:\\apache-tomcat-6.0.35\\counter.txt";
 //생성자( 객체 생성)
 public CounterServlet(){
  
 }
 //객체 생성 직후 실행(count값 read 한 다음에 visitCount로 넣기)
 public void init(){
 
  FileReader fileReader = null;
  BufferedReader bufferedReader = null;
  try {
   fileReader = new FileReader(counterFile);
   bufferedReader = new BufferedReader(fileReader);
   String readCount = bufferedReader.readLine();
   visitCount = Integer.parseInt(readCount);
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  } finally{
   if(bufferedReader!=null){
    try {
     bufferedReader.close();
    } catch (IOException e) {
     e.printStackTrace();
    }
   }
   
  }
  
 }
 //객체 소멸 직전 실행(visitCount 값을 파일로 write)
 public void destroy(){
  FileWriter fileWriter = null;
  PrintWriter printWriter = null;
  File file = null;
  try {
   fileWriter = new FileWriter(counterFile);

   printWriter = new PrintWriter(fileWriter,true);
   printWriter.println(visitCount);
  } catch (IOException e) {
   e.printStackTrace();
  } finally{
   printWriter.close();
  }
 }
 //service() -> doGet() : 클라이언트 요청이 들어올때 마다 호출
 public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException{
  response.setContentType("text/html;charset=UTF-8");
  PrintWriter out = response.getWriter();
  out.println("<html><head><title>카운터</title></head>");
  out.println("<body>");
  visitCount++;//카운터의 값을 1증가
  out.println("당신은 "+visitCount+" 번째 방문자 입니다.");
  out.println("</body></html>");
 }
}
*/

package servlet.lifecycle;

 
import java.io.DataInputStream;
import java.io.DataOutputStream;
 
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
 
import java.io.IOException;
import java.io.PrintWriter;

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

public class CounterServlet extends HttpServlet{
 //변수 저장하는 방법(변수, 파일, DB 세가지 방법이 있다.)
 private int visitCount;
 //카운트 한 값을 저장 시킬 공간
 //private String counterFile = "F:\\apache-tomcat-6.0.35\\counter.dat";
 private String counterFile;
 //생성자( 객체 생성)
 public CounterServlet(){
  
 }
 //객체 생성 직후 실행(count값 read 한 다음에 visitCount로 넣기)
 public void init(){
  System.out.println("counterFile : "+counterFile);
  ServletConfig conf = getServletConfig();
  counterFile = conf.getInitParameter("saveFile");
  System.out.println("counterFile : "+counterFile);
  DataInputStream dataInputStream = null;
  try {
   dataInputStream = new DataInputStream(new FileInputStream(counterFile));
   visitCount = dataInputStream.readInt();
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  } finally{
   if(dataInputStream!=null){
    try {
     dataInputStream.close();
    } catch (IOException e) {
     e.printStackTrace();
    }
   }
  }
  
 }
 //객체 소멸 직전 실행(visitCount 값을 파일로 write)
 public void destroy(){
  DataOutputStream dataOutputStream = null;
  try {
   dataOutputStream = new DataOutputStream(new FileOutputStream(counterFile));
   dataOutputStream.writeInt(visitCount);
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  } finally{
   if( dataOutputStream!=null){
    try {
     dataOutputStream.close();
    } catch (IOException e) {
     e.printStackTrace();
    }
   }
  }
 }
 //service() -> doGet() : 클라이언트 요청이 들어올때 마다 호출
 public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException{
  response.setContentType("text/html;charset=UTF-8");
  PrintWriter out = response.getWriter();
  out.println("<html><head><title>카운터</title></head>");
  out.println("<body>");
  visitCount++;//카운터의 값을 1증가
  try{
   Thread.sleep(5000);
   
  }catch(Exception e){
   
  }
  out.println("당신은 "+visitCount+" 번째 방문자 입니다.");
  out.println("</body></html>");
 }
}