Spring Data REST를 사용한 건에 대하여

@Entity
class Member(
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    val id: Long? = null,

    var name: String,
    var email: String,
    var department: String,
)

interface MemberRepository : JpaRepository<Member, Long>

@RepositoryRestResource(
    path = "users",                    // 엔드포인트 경로를 /api/users 로 변경
    collectionResourceRel = "users",   // 컬렉션 JSON 키 이름 변경
    itemResourceRel = "user",          // 단일 항목 JSON 키 이름 변경
)
interface MemberRepository : JpaRepository<Member, Long>

@RepositoryRestResource(exported = false) // 이 리포지토리는 REST API로 노출되지 않음
interface InternalLogRepository : JpaRepository<InternalLog, Long>

interface MemberRepository : JpaRepository<Member, Long> {

    @RestResource(exported = false)
    override fun deleteById(id: Long)  // DELETE 엔드포인트만 비활성화
}

interface MemberRepository : JpaRepository<Member, Long> {

    fun findByDepartment(@Param("department") department: String): List<Member>

    fun findByNameContaining(@Param("name") name: String): List<Member>

    @RestResource(path = "byEmail", rel = "byEmail")
    fun findByEmail(@Param("email") email: String): Member?
}

@Entity
class Post(
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    val id: Long? = null,

    var title: String,
    var content: String,

    @ManyToOne
    @JoinColumn(name = "member_id")
    var author: Member? = null,

    @OneToMany(mappedBy = "post", cascade = [CascadeType.ALL])
    val comments: MutableList<Comment> = mutableListOf(),
)

@Entity
class Comment(
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    val id: Long? = null,

    var content: String,

    @ManyToOne
    @JoinColumn(name = "post_id")
    var post: Post? = null,
)

interface PostRepository : JpaRepository<Post, Long>

interface CommentRepository : JpaRepository<Comment, Long>

@Projection(name = "summary", types = [Member::class])
interface MemberSummary {
    fun getName(): String
    fun getDepartment(): String
}

@Projection(name = "detail", types = [Post::class])
interface PostDetail {
    fun getTitle(): String
    fun getContent(): String
    fun getAuthor(): MemberSummary  // 연관된 Member를 인라인으로 포함
}

@RepositoryRestResource(excerptProjection = MemberSummary::class)
interface MemberRepository : JpaRepository<Member, Long>

@Component
@RepositoryEventHandler(Member::class)
class MemberEventHandler {

    private val log = LoggerFactory.getLogger(MemberEventHandler::class.java)

    @HandleBeforeCreate
    fun handleBeforeCreate(member: Member) {
        log.info("Member 생성 전: {}", member.name)
        // 예: 이름 공백 제거 등 전처리
        member.name = member.name.trim()
    }

    @HandleAfterCreate
    fun handleAfterCreate(member: Member) {
        log.info("Member 생성 완료: id={}, name={}", member.id, member.name)
        // 예: 알림 발송, 감사 로그 기록 등
    }

    @HandleBeforeSave
    fun handleBeforeSave(member: Member) {
        log.info("Member 수정 전: id={}", member.id)
    }

    @HandleBeforeDelete
    fun handleBeforeDelete(member: Member) {
        log.info("Member 삭제 전: id={}", member.id)
    }
}

@Component("beforeCreateMemberValidator")
class MemberValidator : Validator {

    override fun supports(clazz: Class<*>): Boolean {
        return Member::class.java.isAssignableFrom(clazz)
    }

    override fun validate(target: Any, errors: Errors) {
        val member = target as Member

        if (member.name.isBlank()) {
            errors.rejectValue("name", "name.required", "이름은 필수입니다.")
        }

        if (!member.email.contains("@")) {
            errors.rejectValue("email", "email.invalid", "올바른 이메일 형식이 아닙니다.")
        }
    }
}

@Configuration
class RestValidationConfig(
    private val memberValidator: MemberValidator,
) : RepositoryRestConfigurer {

    override fun configureValidatingRepositoryEventListener(
        listener: ValidatingRepositoryEventListener,
    ) {
        listener.addValidator("beforeCreate", memberValidator)
        listener.addValidator("beforeSave", memberValidator)
    }
}