✨Feat: 알람기능 관련 엔티티 구현

Author: imjuyongp

src/main/java/com/be/sportizebe/domain/notification/entity/JoinClubRequest.java

@@ -0,0 +1,54 @@
+package com.be.sportizebe.domain.notification.entity;
+
+import com.be.sportizebe.domain.club.entity.Club;
+import com.be.sportizebe.domain.user.entity.User;
+import com.be.sportizebe.global.common.BaseTimeEntity;
+import jakarta.persistence.*;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Entity
+@Getter
+@Builder
+@AllArgsConstructor
+@NoArgsConstructor
+@Table(name = "join_club_request", uniqueConstraints = {
+    @UniqueConstraint(columnNames = {"user_id", "club_id"})
+})
+public class JoinClubRequest extends BaseTimeEntity {
+
+  public enum JoinClubRequestStatus {
+    PENDING,   // 대기
+    ACCEPTED,  // 승인
+    REJECTED   // 거절
+  }
+
+  @Id
+  @GeneratedValue(strategy = GenerationType.IDENTITY)
+  private Long id;
+
+  @ManyToOne(fetch = FetchType.LAZY)
+  @JoinColumn(name = "user_id", nullable = false)
+  private User user; // 가입 신청자
+
+  @ManyToOne(fetch = FetchType.LAZY)
+  @JoinColumn(name = "club_id", nullable = false)
+  private Club club; // 가입 신청 대상 동호회
+
+  @Enumerated(EnumType.STRING)
+  @Column(nullable = false)
+  @Builder.Default
+  private JoinClubRequestStatus status = JoinClubRequestStatus.PENDING;
+
+  // 가입 승인 시 상태 변경
+  public void accept() {
+    this.status = JoinClubRequestStatus.ACCEPTED;
+  }
+
+  // 가입 거절 시 상태 변경
+  public void reject() {
+    this.status = JoinClubRequestStatus.REJECTED;
+  }
+}

src/main/java/com/be/sportizebe/domain/notification/entity/Notification.java

@@ -0,0 +1,61 @@
+package com.be.sportizebe.domain.notification.entity;
+
+import com.be.sportizebe.domain.user.entity.User;
+import com.be.sportizebe.global.common.BaseTimeEntity;
+import jakarta.persistence.*;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Entity
+@Getter
+@Builder
+@AllArgsConstructor
+@NoArgsConstructor
+@Table(name = "notifications", indexes = {
+    @Index(name = "idx_notification_receiver", columnList = "receiver_id"),
+    @Index(name = "idx_notification_is_read", columnList = "receiver_id, is_read")
+})
+public class Notification extends BaseTimeEntity {
+
+  public enum NotificationType {
+    JOIN_REQUEST,   // 가입 신청 (동호회장에게)
+    JOIN_APPROVED,  // 가입 승인 (신청자에게)
+    JOIN_REJECTED,  // 가입 거절 (신청자에게)
+    CHAT,           // 새 채팅 메시지
+    COMMENT         // 새 댓글
+  }
+
+  @Id
+  @GeneratedValue(strategy = GenerationType.IDENTITY)
+  private Long id;
+
+  @ManyToOne(fetch = FetchType.LAZY)
+  @JoinColumn(name = "receiver_id", nullable = false)
+  private User receiver; // 알림 수신자
+
+  @Enumerated(EnumType.STRING)
+  @Column(nullable = false)
+  private NotificationType type;
+
+  @Column(nullable = false)
+  private String message; // 알림 메시지
+
+  @Column(nullable = false)
+  @Builder.Default
+  private Boolean isRead = false;
+
+  // 가입 신청 관련 알림용 (JOIN_REQUEST, JOIN_APPROVED, JOIN_REJECTED)
+  @ManyToOne(fetch = FetchType.LAZY)
+  @JoinColumn(name = "join_request_id")
+  private JoinClubRequest joinClubRequest;
+
+  // 댓글 알림용 - targetId와 targetType으로 다형성 처리
+  // COMMENT: postId, CHAT: chatRoomId 등
+  private Long targetId;
+
+  public void markAsRead() {
+    this.isRead = true;
+  }
+}