Servlet 으로 회원 관리 웹 애플리케이션 만들어 보기
서블릿으로 회원 등록 HTML form 만들기
경로 ) hello.servlet.web.servlet
package hello.servlet1.web.servlet;
import org.springframework.context.annotation.EnableLoadTimeWeaving;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
@WebServlet(name = "memberFormServlet",urlPatterns = "/servlet/members/new-form")
public class MemberFormServlet extends HttpServlet {
@Override
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html");
response.setCharacterEncoding("utf-8");
PrintWriter w = response.getWriter();
w.write("<!DOCTYPE html>\n" +
"<html>\n" +
"<head>\n" +
" <meta charset=\"UTF-8\">\n" +
" <title>Title</title>\n" +
"</head>\n" +
"<body>\n" +
"<form action=\"/servlet/members/save\" method=\"post\">\n" +
" username: <input type=\"text\" name=\"username\" />\n" +
" age: <input type=\"text\" name=\"age\" />\n" +
" <button type=\"submit\">전송</button>\n" + "</form>\n" +
"</body>\n" +
"</html>\n");
}
}
MemberFormServlet은 단순하게 회원 정보를 입력할 수 있는 HTML Form을 만들어 응답한다.
자바 코드로 HTML을 제공해야 하므로 쉽지 않은 작업이다.
실행 : http://localhost:8080/servlet/members/new-for
HTML Form 데이터를 POST로 전송해도, 전달 받은 서블릿을 아직 만들지 않았다.
그래서 오류가 발생하는 것이 정상이다.
회원 저장 만들기
경로) hello.servlet.web.servlet
package hello.servlet1.web.servlet;
import hello.servlet1.domain.member.Member;
import hello.servlet1.domain.member.MemberRepository;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
@WebServlet(name="memberSaveServlet",urlPatterns = "/servlet/members/save")
public class MemberSaveServlet extends HttpServlet {
private MemberRepository memberRepository = MemberRepository.getInstance();
@Override
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("MemberSaveServlet.service");
String username = request.getParameter("username");
int age = Integer.parseInt(request.getParameter("age"));
Member member = new Member(username, age);
System.out.println("member = " + member);
memberRepository.save(member);
response.setContentType("text/html");
response.setCharacterEncoding("utf-8");
PrintWriter w = response.getWriter();
w.write("<html>\n" +
"<head>\n" +
" <meta charset=\"UTF-8\">\n" + "</head>\n" +
"<body>\n" +
"성공\n" +
"<ul>\n" +
" <li>id="+member.getId()+"</li>\n" +
" <li>username="+member.getUsername()+"</li>\n" +
" <li>age="+member.getAge()+"</li>\n" + "</ul>\n" +
"<a href=\"/index.html\">메인</a>\n" + "</body>\n" +
"</html>");
}
}
결과
MeberSaveServlet은 다음 순서로 동작한다.
1. 파라미터를 조회해서 Member 객체를 만든다
2. Member 객체를 MemberRepository를 통해 저장한다.
3. Member 객체를 사용해서 결과 화면용 HTML을 동적으로 만들어서 응답한다.
실행 : http://localhost:8080/servlet/members/new-form
데이터가 전송되고, 저장 결과를 확인할 수 있다.
저장된 모든 회원 목록을 조회하는 기능 만들기
경로 ) hello.servlet.web.servlet
package hello.servlet1.web.servlet;
import hello.servlet1.domain.member.Member;
import hello.servlet1.domain.member.MemberRepository;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;
@WebServlet(name = "memberListServlet", urlPatterns = "/servlet/members")
public class MemberListServlet extends HttpServlet {
private MemberRepository memberRepository = MemberRepository.getInstance();
@Override
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html");
response.setCharacterEncoding("utf-8");
List<Member> members = memberRepository.findAll();
PrintWriter w = response.getWriter();
w.write("<html>");
w.write("<head>");
w.write(" <meta charset=\"UTF-8\">");
w.write(" <title>Title</title>");
w.write("</head>");
w.write("<body>");
w.write("<a href=\"/index.html\">메인</a>");
w.write("<table>");
w.write(" <thead>");
w.write(" <th>id</th>");
w.write(" <th>username</th>");
w.write(" <th>age</th>");
w.write(" </thead>");
w.write(" <tbody>");
for (Member member : members) {
w.write(" <tr>");
w.write(" <td>" + member.getId() + "</td>");
w.write(" <td>" + member.getUsername() + "</td>");
w.write(" <td>" + member.getAge() + "</td>");
w.write(" </tr>");
}
w.write(" </tbody>");
w.write("</table>");
w.write("</body>");
w.write("</html>");
}
}MemberListServlet은 다음 순서로 동작한다.
1. memberRepository.findAll()을 통해 모든 회원을 조히
2. 회원 목록 HTML을 for 루프를 통해서 회원 수 만큼 동작으로 생성하고 응답한다.
binubibi