언제 이용하는가?
하나의 요청에서 HttpServletRequest 객체가 소멸하기 까지 상태정보를 유지하고자 할 때, 한번의 요청으로 실행된 페이지끼리 정보를 공유하고자 할 때 사용되며, 디스패처에 의한 요청재지정을 하기 전 HttpServletRequest 객체의 setAttribute( ) 메소드로 데이터를 등록하고 요청 재지정으로 HttpServletRequest 객체가 전달된 페이지에서 getAttribute( ) 메소드로 추출할 수 있다.
Request 단위 정보 공유
하나의 요청에 의해 실행되는 페이지간의 정보를 공유하는 예제를 살펴보자
memberInput.html
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<h3>회원 가입하기</h3>
<form method="post" action="memberReg">
<p>아이디</p>
<input type="text" name="userId" placeholder="이름을 입력해 주세요">
<p>패스워드</p>
<input type="password" name="passwd" placeholder="패스워드를 입력해 주세요">
<p>이메일</p>
<input type="text" name="email" placeholder="이메일을 입력해 주세요">
<p>이메일 수신여부</p>
<input type="radio" name="emailAgree" value="yes">예
<input type="radio" name="emailAgree" value="no" checked>아니오
<p>관심사항</p>
<input type="checkbox" name="interest" value="IT">IT/인터넷
<input type="checkbox" name="interest" value="movie">영화
<input type="checkbox" name="interest" value="music">음악
<input type="checkbox" name="interest" value="book">책
<input type="checkbox" name="interest" value="food">음식
<p>핸드폰</p>
<select name="hp_1">
<option value="010">010</option>
<option value="010">011</option>
</select>
<input type="text" name="hp_2" placeholder="핸드폰 번호를 입력해주세요">
<p>자기소개</p>
<textarea name="introduce" placeholder="자기소개를 입력해주세요" cols="30" rows="4"></textarea>
<br/>
<input type="submit" value="전송">
</form>
</body>
</html>
Member.java
package job.study.web;
public class Member {
private String userId;
private String passwd;
private String email;
private String hp_1;
private String hp_2;
private String emailAgree; //라디오
private String[] interest; //체크박스
private String introduce;
public String getUserId() {
return userId;
}
public void setUserId(String userId) {
this.userId = userId;
}
public String getPasswd() {
return passwd;
}
public void setPasswd(String passwd) {
this.passwd = passwd;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getHp_1() {
return hp_1;
}
public void setHp_1(String hp_1) {
this.hp_1 = hp_1;
}
public String getHp_2() {
return hp_2;
}
public void setHp_2(String hp_2) {
this.hp_2 = hp_2;
}
public String getEmailAgree() {
return emailAgree;
}
public void setEmailAgree(String emailAgree) {
this.emailAgree = emailAgree;
}
public String[] getInterest() {
return interest;
}
public void setInterest(String[] interest) {
this.interest = interest;
}
public String getIntroduce() {
return introduce;
}
public void setIntroduce(String introduce) {
this.introduce = introduce;
}
}
MemberRegServlet.java
package job.study.web;
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;
/**
* Servlet implementation class jobTestServlet
*/
@WebServlet("/memberReg")
public class MemberRegServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public MemberRegServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// TODO Auto-generated method stub
response.setContentType("text/html);charset=UTF-8");
//요청정보 몸체에 있는 문자열들을 인자값으로 지정한 문자코드로 인코딩한다.
request.setCharacterEncoding("UTF-8");
//getParameter는 중복되지 않고 유일하게 하나만 넘어올 떄 사용된다.
//getParameter의 반환값은 String이다.
String userId = request.getParameter("userId");
String passwd = request.getParameter("passwd");
String email = request.getParameter("email");
String hp_1 = request.getParameter("hp_1");
String hp_2 = request.getParameter("hp_2");
String emailAgree = request.getParameter("emailAgree");
//getParameterValues는 체크박스처럼 다중 선택되는 입력 양식의 값을 추출할 떄 사용된다.
String[] interest = request.getParameterValues("interest");
String introduce = request.getParameter("introduce");
//멤버객체에 회원정보를 저장한다.
Member member = new Member();
member.setUserId(userId);
member.setPasswd(passwd);
member.setEmail(email);
member.setHp_1(hp_1);;
member.setHp_2(hp_2);
member.setEmailAgree(emailAgree);
member.setInterest(interest);
member.setIntroduce(introduce);
//HttServletRequest 객체에 회원정보를 등록한다.
request.setAttribute("member",member);
//디스패처에 의한 요청 재지정
//멤버객체를 출력 할 서블릿의 URI를 지정한다.
RequestDispatcher rd = request.getRequestDispatcher("memberOutput");
rd.forward(request, response);
}
}
MemberOutputServlet.java
package job.study.web;
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 ResumeOutputServlet
*/
@WebServlet("/memberOutput")
public class MemberOutputServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public MemberOutputServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// TODO Auto-generated method stub
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
//HttpServletRequest 객체에 등록된 회원 정보를 추출한다.
Member member = (Member) request.getAttribute("member");
out.println("<h3>회원아이디 : "+member.getUserId()+"</h3>");
out.println("<h3>패스워드 : "+member.getPasswd()+"</h3>");
out.println("<h3>이메일 : "+member.getEmail()+"</h3>");
out.println("<h3>핸드폰 : "+member.getHp_1()+"-"+member.getHp_2()+"</h3>");
out.println("<h3>이메일수신여부 : "+member.getEmailAgree()+"</h3>");
out.println("<h3>관심사항: </h3>");
String[] interest = member.getInterest();
for(int i=0; i< interest.length;i++)
{
if(i+1 == interest.length) {
out.println(interest[i]);
}else {
out.println(interest[i]+",");
}
}
out.println("<h3>자기소개 : "+member.getIntroduce()+"</h3>");
out.close();
}
}
실행결과
