Servlet 5 - 서블릿으로 회원관리 만들어보기

Jan 10, 2023

8 mins read

스프링MVC1

스프링 mvc1

순수 서블릿을 사용해 간단한 회원관리 웹앱을 만들어보자. (인프런 강의 듣는 중)

1. 회원 도메인 모델, 회원 저장관리 레포지토리 생성

hello.servlet.domain.member패키지를 만들고 Member, MemberRepository클래스를 만든다.
Member 회원 도메인 모델

package hello.servlet.domain.member;

import lombok.Getter;
import lombok.Setter;

@Getter @Setter
public class Member {

	private Long id;
	private String username;
	private int age;
	
	public Member() {
	}
	
	public Member(String username, int age) {
		this.username = username;
		this.age = age;
	}
	
}

MemberRepository 회원 저장소

package hello.servlet.domain.member;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/*
 * 동시성 문제가 고려되어 있지 않음, 실무에서는 ConcorrentHashMap, AtomicLong 사용 고려
 * */

//간단하게 만드는거기 때문에 싱글톤으로 만들어서 사용 
public class MemberRepository {

	private static Map<Long, Member> store = new HashMap<>();
	private static long sequence = 0L;
	
	private static final MemberRepository instance = new MemberRepository();
	
	//getInstance로만 이 클래스 store 데이터를 가져올 수 있게만듬
	public static MemberRepository getInstance() {
		return instance;
	}
	
	private MemberRepository(){
	}
	
	public Member save(Member member) {
		member.setId(++sequence);
		store.put(member.getId(), member);
		return member;
	}
	
	public Member findById(Long id) {
		return store.get(id); 
	}
	
	public List<Member> findAll(){
		return new ArrayList<>(store.values());
	}
	
	//테스트하기 용이하게 Map 데이터 초기화 메소드 만듬
	public void clearStore() {
		store.clear();
	}
	
}

만들어진 회원 도메인 모델과 회원 저장소는 JUnit과 AssertJ Api를 통해 테스트해 볼 수 있다.
이클립스 프로젝트에서 src.test에 hello.servlet.domain.member를 똑같이 만들고 테스트 클래스 MemberRepositoryTest를 하나 만든다.

package hello.servlet.domain.member;

import java.util.List;

import org.assertj.core.api.Assertions;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.Test;

public class MemberRepositoryTest {
	
	MemberRepository memberRepository = MemberRepository.getInstance();
	
	//각 @Test 테스트 후 memberRepository 초기화
	@AfterEach
	void afterEach(){
		memberRepository.clearStore();		
	}
	
	//회원정보 저장해서 맞게 저장되었나 확인해보기
	@Test
	void save() { 
		
		//given
		Member member = new Member("aroong", 20);
		
		//when
		Member savedMember = memberRepository.save(member);
		
		//then
		Member findMember = memberRepository.findById(savedMember.getId());

		//검증
		Assertions.assertThat(findMember).isEqualTo(savedMember);
		
	}
	
	//회원정보 두명 저장해서 두개 정보 맞게 저장되었나 확인해보기
	@Test
	void findAll() {
		//given
		Member member1 = new Member("aroong1", 20);
		Member member2 = new Member("aroong2", 30);
		
		memberRepository.save(member1);
		memberRepository.save(member2);
		
		//when
		List<Member> result = memberRepository.findAll();
		
		//then
		Assertions.assertThat(result.size()).isEqualTo(2);
		Assertions.assertThat(result).contains(member1, member2);
	}

}

Junit Test 컴파일 돌려보면 두개 @Test가 성공하는걸 볼 수 있다.

member_junit_test

2. 서블릿으로 회원관리 웹앱 만들기

MemberFormServlet클래스를 생성하여 /new-form으로 접속하면 회원가입을 받을 수 있게 HTML FORM을 제공한다.

package hello.servlet.web.servlet;

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

import hello.servlet.domain.member.MemberRepository;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

@WebServlet(name = "memberFormServlet", urlPatterns = "/servlet/members/new-form")
public class MemberFormServlet 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");
		
		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");
		
	}
	
}

위 회원가입 HTML FORM에서 데이터를 입력하고 전송을 누르면 /servlet/members/save로 이동한다.
/servlet/members/save용 MemberSaveServlet 클래스도 생성하고 여기서 회원 저장소에 회원정보를 저장한다.
저장 후에는 결과용 HTML을 전송한다.

package hello.servlet.web.servlet;

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

import hello.servlet.domain.member.Member;
import hello.servlet.domain.member.MemberRepository;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

@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 {
	
		//response.setContentType("text/html");
		//response.setCharacterEncoding("utf-8");
		
		System.out.println("MemberSaveServlet.service");
		String username = request.getParameter("username");
		int age = Integer.parseInt(request.getParameter("age"));
		
		Member member = new Member(username, age);
		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>");
	}
	
}

저장된 모든 회원 목록을 조회하는 기능도 만들어본다.

package hello.servlet.web.servlet;

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

import hello.servlet.domain.member.Member;
import hello.servlet.domain.member.MemberRepository;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

@WebServlet(name = "memerListServlet", urlPatterns = "/servlet/members")
public class MemerListServlet extends HttpServlet{

	private MemberRepository memberRepository = MemberRepository.getInstance();
	
	@Override
	protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		List<Member> members = memberRepository.findAll();
		
		response.setContentType("text/html");
		response.setCharacterEncoding("utf-8");
		
		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>");
	}
	
}

회원 가입
회원 가입 결과
회원 목록