spring_boot(게시판)_2024-10-08

게시판 기능

① 글 작성, 조회, 수정, 삭제, 리스트 조회, 댓글, 좋아요 기능

② 자세한 기능 설계는 [Spring Boot] 게시판 만들기 1 - 설계 & 결과 참고

 

요청 클래스 생성 및 소스 코드 작성하기

① @Getter / @ Settter

클래스 레벨에 선언된 두 어노테이션은 롬복(Lombok) 라이브러리에서 제공해 주는 기능으로, 클래스에 선언된 모든 멤버 변수에 대한 getter와 settter를 생성해 주는 역할을 합니다.
 
인텔리제이(IntelliJ)는 기본적으로 롬복(Lombok) 플러그인이 설치되어 있지만, 이클립스(STS)는 라이브러리를 수동으로 설치해 주어야 합니다. 만약 이클립스(STS)를 사용하신다면, 코드의 간결함과 가독성을 위해 롬복 설치하기를 진행하시는 것을 권장드립니다.

 

②  클래스의 멤버 변수가 왜 칼럼 개수보다 적은 거죠?

게시글 테이블 구조를 다시 한번 봐주시기 바랍니다. 이 중에서 사용자가 게시판에 글을 작성할 때 입력(선택)하는 필드는 제목(title), 내용(content), 작성자(writer), 공지글 여부(notice_yn)까지 총 네 가지 정도입니다.

id는 auto_increment 속성에 의해 자동으로 1씩 증가되므로 게시글 생성(INSERT) 시점에는 필요가 없으나, 게시글을 수정(UPDATE) 할 때 SQL 쿼리의 WHERE 조건으로 id(PK)를 사용하기 때문에 선언해 주었습니다.

조회 수(view_cnt)와 삭제 여부(delete_yn)는 무조건 0으로 생성되어야 하며, 생성일시(created_date)는 현재 시간으로, 수정일시(modified_date)는 NULL로 설정해 주면 됩니다. 삭제 여부(delete_yn) 칼럼의 용도는 뒤에서 설명드리도록 하겠습니다.

 

게시글 응답(Response) 클래스 생성하기

다음은 사용자에게 보여줄 데이터를 처리할 응답용 클래스입니다. 응답 클래스에는 테이블의 모든 칼럼을 멤버 변수로 선언해 주시면 됩니다. 요청 클래스와 동일한 경로에 PostResponse 클래스를 추가하고, 다음의 코드를 작성해 주세요.

package com.mysite.sbb.answer;

import java.time.LocalDateTime;
import java.util.Set;

import com.mysite.sbb.question.Question;
import com.mysite.sbb.user.SiteUser;

import jakarta.persistence.Column;
import jakarta.persistence.Entity;
import jakarta.persistence.GeneratedValue;
import jakarta.persistence.GenerationType;
import jakarta.persistence.Id;
import jakarta.persistence.ManyToMany;
import jakarta.persistence.ManyToOne;
import lombok.Getter;
import lombok.Setter;

@Getter
@Setter
@Entity
public class Answer {
	@Id
	@GeneratedValue(strategy = GenerationType.IDENTITY)
	private Integer id;

	@Column(columnDefinition = "TEXT")
	private String content;

	private LocalDateTime createDate;

	@ManyToOne
	private Question question;

	@ManyToOne
	private SiteUser author;

	private LocalDateTime modifyDate;
	
	@ManyToMany
    Set<SiteUser> voter;
}

package com.mysite.sbb.question;

import java.time.LocalDateTime;
import java.util.List;
import java.util.Set;

import com.mysite.sbb.answer.Answer;
import com.mysite.sbb.user.SiteUser;

import jakarta.persistence.CascadeType;
import jakarta.persistence.Column;
import jakarta.persistence.Entity;
import jakarta.persistence.GeneratedValue;
import jakarta.persistence.GenerationType;
import jakarta.persistence.Id;
import jakarta.persistence.ManyToMany;
import jakarta.persistence.ManyToOne;
import jakarta.persistence.OneToMany;
import lombok.Getter;
import lombok.Setter;

@Getter
@Setter
@Entity
public class Question {
	@Id
	@GeneratedValue(strategy = GenerationType.IDENTITY)
	private Integer id;

	@Column(length = 200)
	private String subject;

	@Column(columnDefinition = "TEXT")
	private String content;

	private LocalDateTime createDate;

	@OneToMany(mappedBy = "question", cascade = CascadeType.REMOVE)
	private List<Answer> answerList;

	@ManyToOne
	private SiteUser author;

	private LocalDateTime modifyDate;
	
	@ManyToMany
    Set<SiteUser> voter;
}

package com.mysite.sbb.user;

import jakarta.persistence.Column;
import jakarta.persistence.Entity;
import jakarta.persistence.GeneratedValue;
import jakarta.persistence.GenerationType;
import jakarta.persistence.Id;

import lombok.Getter;
import lombok.Setter;

@Getter
@Setter
@Entity
public class SiteUser {

	@Id
	@GeneratedValue(strategy = GenerationType.IDENTITY)
	private Long id;

	@Column(unique = true)
	private String username;

	private String password;

	@Column(unique = true)
	private String email;
}

 

인터페이스 생성하기

다음은 데이터베이스와의 통신 역할을 할 Controller 인터페이스입니다. 마찬가지로 com.mysite.sbb 패키지에 Controller  인터페이스를 추가하고, 코드를 작성해 주세요.

package com.mysite.sbb.question;

import java.security.Principal;

import org.springframework.data.domain.Page;
import org.springframework.http.HttpStatus;
import org.springframework.security.access.prepost.PreAuthorize;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.server.ResponseStatusException;

import com.mysite.sbb.answer.AnswerForm;
import com.mysite.sbb.user.SiteUser;
import com.mysite.sbb.user.UserService;

import jakarta.validation.Valid;
import lombok.RequiredArgsConstructor;

@RequestMapping("/question")
@RequiredArgsConstructor
@Controller
public class QuestionController {

	private final QuestionService questionService;
	private final UserService userService;

	@GetMapping("/list")
	public String list(Model model, @RequestParam(value = "page", defaultValue = "0") int page,
			@RequestParam(value = "kw", defaultValue = "") String kw) {
		Page<Question> paging = this.questionService.getList(page, kw);
		model.addAttribute("paging", paging);
		model.addAttribute("kw", kw);
		return "question_list";
	}

	@GetMapping(value = "/detail/{id}")
	public String detail(Model model, @PathVariable("id") Integer id, AnswerForm answerForm) {
		Question question = this.questionService.getQuestion(id);
		model.addAttribute("question", question);
		return "question_detail";
	}

	@PreAuthorize("isAuthenticated()")
	@GetMapping("/create")
	public String questionCreate(QuestionForm questionForm) {
		return "question_form";
	}

	@PreAuthorize("isAuthenticated()")
	@PostMapping("/create")
	public String questionCreate(@Valid QuestionForm questionForm, BindingResult bindingResult, Principal principal) {
		if (bindingResult.hasErrors()) {
			return "question_form";
		}
		SiteUser siteUser = this.userService.getUser(principal.getName());
		this.questionService.create(questionForm.getSubject(), questionForm.getContent(), siteUser);
		return "redirect:/question/list";
	}

	@PreAuthorize("isAuthenticated()")
	@GetMapping("/modify/{id}")
	public String questionModify(QuestionForm questionForm, @PathVariable("id") Integer id, Principal principal) {
		Question question = this.questionService.getQuestion(id);
		if (!question.getAuthor().getUsername().equals(principal.getName())) {
			throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "수정권한이 없습니다.");
		}
		questionForm.setSubject(question.getSubject());
		questionForm.setContent(question.getContent());
		return "question_form";
	}

	@PreAuthorize("isAuthenticated()")
	@PostMapping("/modify/{id}")
	public String questionModify(@Valid QuestionForm questionForm, BindingResult bindingResult, Principal principal,
			@PathVariable("id") Integer id) {
		if (bindingResult.hasErrors()) {
			return "question_form";
		}
		Question question = this.questionService.getQuestion(id);
		if (!question.getAuthor().getUsername().equals(principal.getName())) {
			throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "수정권한이 없습니다.");
		}
		this.questionService.modify(question, questionForm.getSubject(), questionForm.getContent());
		return String.format("redirect:/question/detail/%s", id);
	}

	@PreAuthorize("isAuthenticated()")
	@GetMapping("/delete/{id}")
	public String questionDelete(Principal principal, @PathVariable("id") Integer id) {
		Question question = this.questionService.getQuestion(id);
		if (!question.getAuthor().getUsername().equals(principal.getName())) {
			throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "삭제권한이 없습니다.");
		}
		this.questionService.delete(question);
		return "redirect:/";
	}

	@PreAuthorize("isAuthenticated()")
	@GetMapping("/vote/{id}")
	public String questionVote(Principal principal, @PathVariable("id") Integer id) {
		Question question = this.questionService.getQuestion(id);
		SiteUser siteUser = this.userService.getUser(principal.getName());
		this.questionService.vote(question, siteUser);
		return String.format("redirect:/question/detail/%s", id);
	}
}

package com.mysite.sbb.question;

import java.security.Principal;

import org.springframework.data.domain.Page;
import org.springframework.http.HttpStatus;
import org.springframework.security.access.prepost.PreAuthorize;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.server.ResponseStatusException;

import com.mysite.sbb.answer.AnswerForm;
import com.mysite.sbb.user.SiteUser;
import com.mysite.sbb.user.UserService;

import jakarta.validation.Valid;
import lombok.RequiredArgsConstructor;

@RequestMapping("/question")
@RequiredArgsConstructor
@Controller
public class QuestionController {

	private final QuestionService questionService;
	private final UserService userService;

	@GetMapping("/list")
	public String list(Model model, @RequestParam(value = "page", defaultValue = "0") int page,
			@RequestParam(value = "kw", defaultValue = "") String kw) {
		Page<Question> paging = this.questionService.getList(page, kw);
		model.addAttribute("paging", paging);
		model.addAttribute("kw", kw);
		return "question_list";
	}

	@GetMapping(value = "/detail/{id}")
	public String detail(Model model, @PathVariable("id") Integer id, AnswerForm answerForm) {
		Question question = this.questionService.getQuestion(id);
		model.addAttribute("question", question);
		return "question_detail";
	}

	@PreAuthorize("isAuthenticated()")
	@GetMapping("/create")
	public String questionCreate(QuestionForm questionForm) {
		return "question_form";
	}

	@PreAuthorize("isAuthenticated()")
	@PostMapping("/create")
	public String questionCreate(@Valid QuestionForm questionForm, BindingResult bindingResult, Principal principal) {
		if (bindingResult.hasErrors()) {
			return "question_form";
		}
		SiteUser siteUser = this.userService.getUser(principal.getName());
		this.questionService.create(questionForm.getSubject(), questionForm.getContent(), siteUser);
		return "redirect:/question/list";
	}

	@PreAuthorize("isAuthenticated()")
	@GetMapping("/modify/{id}")
	public String questionModify(QuestionForm questionForm, @PathVariable("id") Integer id, Principal principal) {
		Question question = this.questionService.getQuestion(id);
		if (!question.getAuthor().getUsername().equals(principal.getName())) {
			throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "수정권한이 없습니다.");
		}
		questionForm.setSubject(question.getSubject());
		questionForm.setContent(question.getContent());
		return "question_form";
	}

	@PreAuthorize("isAuthenticated()")
	@PostMapping("/modify/{id}")
	public String questionModify(@Valid QuestionForm questionForm, BindingResult bindingResult, Principal principal,
			@PathVariable("id") Integer id) {
		if (bindingResult.hasErrors()) {
			return "question_form";
		}
		Question question = this.questionService.getQuestion(id);
		if (!question.getAuthor().getUsername().equals(principal.getName())) {
			throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "수정권한이 없습니다.");
		}
		this.questionService.modify(question, questionForm.getSubject(), questionForm.getContent());
		return String.format("redirect:/question/detail/%s", id);
	}

	@PreAuthorize("isAuthenticated()")
	@GetMapping("/delete/{id}")
	public String questionDelete(Principal principal, @PathVariable("id") Integer id) {
		Question question = this.questionService.getQuestion(id);
		if (!question.getAuthor().getUsername().equals(principal.getName())) {
			throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "삭제권한이 없습니다.");
		}
		this.questionService.delete(question);
		return "redirect:/";
	}

	@PreAuthorize("isAuthenticated()")
	@GetMapping("/vote/{id}")
	public String questionVote(Principal principal, @PathVariable("id") Integer id) {
		Question question = this.questionService.getQuestion(id);
		SiteUser siteUser = this.userService.getUser(principal.getName());
		this.questionService.vote(question, siteUser);
		return String.format("redirect:/question/detail/%s", id);
	}
}

package com.mysite.sbb.user;

import org.springframework.dao.DataIntegrityViolationException;
import org.springframework.stereotype.Controller;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;

import jakarta.validation.Valid;
import lombok.RequiredArgsConstructor;

@RequiredArgsConstructor
@Controller
@RequestMapping("/user")
public class UserController {

	private final UserService userService;

	@GetMapping("/signup")
	public String signup(UserCreateForm userCreateForm) {
		return "signup_form";
	}

	@PostMapping("/signup")
	public String signup(@Valid UserCreateForm userCreateForm, BindingResult bindingResult) {
		if (bindingResult.hasErrors()) {
			return "signup_form";
		}

		if (!userCreateForm.getPassword1().equals(userCreateForm.getPassword2())) {
			bindingResult.rejectValue("password2", "passwordInCorrect", "2개의 패스워드가 일치하지 않습니다.");
			return "signup_form";
		}

		try {
			userService.create(userCreateForm.getUsername(), userCreateForm.getEmail(), userCreateForm.getPassword1());
		} catch (DataIntegrityViolationException e) {
			e.printStackTrace();
			bindingResult.reject("signupFailed", "이미 등록된 사용자입니다.");
			return "signup_form";
		} catch (Exception e) {
			e.printStackTrace();
			bindingResult.reject("signupFailed", e.getMessage());
			return "signup_form";
		}

		return "redirect:/";
	}

	@GetMapping("/login")
	public String login() {
		return "login_form";
	}
}

① @controll
과거에는 DAO(Data Access Object) 클래스에 @Repository 어노테이션을 선언해서 해당 클래스가 DB와 통신하는 클래스임을 명시하고는 했습니다. MyBatis는 Mapper(Java 인터페이스)와 XML Mapper(실제로 DB에 접근해서 호출할 SQL 쿼리를 작성(선언)하는 파일)를 통해 DB와 통신합니다.
 
쉽게 말해, XML Mapper에 SQL 쿼리를 선언해 두고 Mapper를 통해 SQL 쿼리를 호출하는데요. Mapper는 XML Mapper에 선언된 SQL 중에서 메서드명과 동일한 id를 가진 SQL 쿼리를 찾아 실행합니다. 예를 들어, 메서드명이 "savePost( )"라고 가정했을 때 SQL id는 "savePost"가 되어야 합니다.
 
여기서 꼭 기억해 주셔야 할 게 있는데요. Mapper에는 @Mapper 어노테이션을 필수적으로 선언해 주어야 하며, Mapper와 XML Mapper는 XML Mapper의 namespace라는 속성을 통해 연결된다는 점입니다. 연결 방법은 뒤에서 예제를 통해 알아보도록 하겠습니다.

② save( )
게시글을 생성하는 INSERT 쿼리를 호출합니다. 파라미터로 전달받는 params는 요청(PostRequest) 클래스의 객체이며, params에는 저장할 게시글 정보가 담기게 됩니다.

③ find( )
특정 게시글을 조회하는 SELECT 쿼리를 호출합니다. 파라미터로 id(PK)를 전달받아 SQL 쿼리의 WHERE 조건으로 사용하며, 쿼리가 실행되면 메서드의 리턴 타입인 응답(PostResponse) 클래스 객체의 각 멤버 변수에 결괏값이 매핑(바인딩)됩니다.

④ update( )
게시글 정보를 수정하는 UPDATE 쿼리를 호출합니다. save( )와 마찬가지로 요청(PostRequest) 클래스의 객체를 파라미터로 전달받으며, params에는 수정할 게시글 정보가 담기게 됩니다. save( )와 차이가 있다면, UPDATE 쿼리의 WHERE 조건으로 사용되는 id(PK)에도 값이 담긴다는 점입니다.

⑤ delete( )
게시글을 삭제 처리하는 UPDATE 쿼리를 호출합니다. findById( )와 마찬가지로 id(PK)를 파라미터로 전달받아 SQL 쿼리의 WHERE 조건으로 사용하게 되며, SQL 쿼리가 실행되면 삭제 여부(delete_yn) 칼럼의 상태 값을 0(false)에서 1(true)로 업데이트합니다.
 
삭제 여부(delete_yn)는 칼럼의 상태 값을 기준으로 삭제된 데이터(1)인지, 삭제되지 않은 데이터(0)인지 구분해 주는 역할을 합니다. 사용자에게 데이터를 보여줄 땐 삭제 여부가 0(false)인 데이터만 노출하게 됩니다.
 
실무에서는 데이터가 DELETE(물리적인 삭제) 되어버리면 리스크(손실)가 크기 때문에 논리적인 삭제 방식을 이용합니다.

⑥ findAll( )
게시글 목록을 조회하는 SELECT 쿼리를 호출합니다. findById( )는 id(PK)를 기준으로 하나의 게시글을 조회한다면, 해당 메서드는 여러 개의 게시글(PostResponse)을 리스트(List)에 담아 리턴해주는 역할을 합니다.

⑦ count( )
전체 게시글 수를 조회하는 SELECT 쿼리를 호출합니다. 당장은 사용되지 않지만, 추후에 페이징 기능을 구현하면서 사용하게 됩니다.

 

DatabaseConfig 클래스 수정하기

package com.mysite.sbb;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.config.annotation.authentication.configuration.AuthenticationConfiguration;
import org.springframework.security.config.annotation.method.configuration.EnableMethodSecurity;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.security.web.SecurityFilterChain;
import org.springframework.security.web.header.writers.frameoptions.XFrameOptionsHeaderWriter;
import org.springframework.security.web.util.matcher.AntPathRequestMatcher;

@Configuration
@EnableWebSecurity
@EnableMethodSecurity(prePostEnabled = true)
public class SecurityConfig {
	@Bean
	SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
		http.authorizeHttpRequests((authorizeHttpRequests) -> authorizeHttpRequests
				.requestMatchers(new AntPathRequestMatcher("/**")).permitAll())
				.csrf((csrf) -> csrf.ignoringRequestMatchers(new AntPathRequestMatcher("/h2-console/**")))
				.headers((headers) -> headers.addHeaderWriter(
						new XFrameOptionsHeaderWriter(XFrameOptionsHeaderWriter.XFrameOptionsMode.SAMEORIGIN)))
				.formLogin((formLogin) -> formLogin.loginPage("/user/login").defaultSuccessUrl("/"))
				.logout((logout) -> logout.logoutRequestMatcher(new AntPathRequestMatcher("/user/logout"))
						.logoutSuccessUrl("/").invalidateHttpSession(true));
		return http.build();
	}

	@Bean
	PasswordEncoder passwordEncoder() {
		return new BCryptPasswordEncoder();
	}

	@Bean
	AuthenticationManager authenticationManager(AuthenticationConfiguration authenticationConfiguration)
			throws Exception {
		return authenticationConfiguration.getAuthenticationManager();
	}
}

 

이번에는 게시글을 관리할 tb_post 테이블을 생성하고, MyBatis를 이용해서 기본적인 CRUD 쿼리를 작성하고, JUnit을 이용해서 단위 테스트를 해보았습니다. 다음 글부터는 MVC 패턴의 모든 영역을 처리하게 되는데요. 개발 순서는 다음과 같습니다.

① 사용자의 요구를 처리하는 비즈니스 로직이 작성되는 모델(Model) 영역

② 사용자가 보는 화면을 의미하는 뷰(View) 영역

③ 모델(Model)과 뷰(View)의 연결고리 역할을 해주는 컨트롤러(Controller) 영역

모델(Model) 영역은 일반적으로 서비스 레이어(Service Layer)라고 표현하며, 뷰(View) 영역은 프레젠테이션 레이어(Presentation Layer) 또는 UI(User Interface)라고 표현합니다. 각 영역별 처리 방법은 다음 글에서 자세히 알아보도록 하겠습니다.
 
추가적으로 이번 글부터는 작업한 프로젝트를 압축해서 첨부하도록 하겠습니다.오늘도 글을 읽어주신 여러분께 진심으로 감사의 말씀을 전합니다. 좋은 하루 보내세요.

 

sbb.zip

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