[BE/#17] Feat : 도메인 클래스 생성 (Comment, Assignee)

DB의 테이블과 같은 구성을 가진 도메인 클래스 생성
- Comment
- Assignee (다대다 관계 테이블, 불 필요시 추후 삭제할 수 있다.)

BE/src/main/java/com/codesquad/issuetracker/ragdoll/domain/Assignee.java

@@ -0,0 +1,46 @@
+package com.codesquad.issuetracker.ragdoll.domain;
+
+public class Assignee {
+
+    private Integer id;
+
+    private Long issueId;
+
+    private Long userId;
+
+    public Assignee() {}
+
+    private Assignee(Integer id, Long issueId, Long userId) {
+        this.id = id;
+        this.issueId = issueId;
+        this.userId = userId;
+    }
+
+    public static Assignee create(Integer id, Long issueId, Long userId) {
+        return new Assignee(id, issueId, userId);
+    }
+
+    public Integer getId() {
+        return id;
+    }
+
+    public void setId(Integer id) {
+        this.id = id;
+    }
+
+    public Long getIssueId() {
+        return issueId;
+    }
+
+    public void setIssueId(Long issueId) {
+        this.issueId = issueId;
+    }
+
+    public Long getUserId() {
+        return userId;
+    }
+
+    public void setUserId(Long userId) {
+        this.userId = userId;
+    }
+}

BE/src/main/java/com/codesquad/issuetracker/ragdoll/domain/Comment.java

@@ -0,0 +1,109 @@
+package com.codesquad.issuetracker.ragdoll.domain;
+
+import java.time.LocalDateTime;
+
+public class Comment {
+
+    private Long id;
+
+    private String description;
+
+    private LocalDateTime createdDateTime;
+
+    private Long issueId;
+
+    private Long userId;
+
+    public Comment() {}
+
+    private Comment(Long id, String description, LocalDateTime createdDateTime, Long issueId, Long userId) {
+        this.id = id;
+        this.description = description;
+        this.createdDateTime = createdDateTime;
+        this.issueId = issueId;
+        this.userId = userId;
+    }
+
+    public static Comment create(Long id, String description, LocalDateTime createdDateTime, Long issueId, Long userId) {
+        return new Comment(id, description, createdDateTime, issueId, userId);
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+    public LocalDateTime getCreatedDateTime() {
+        return createdDateTime;
+    }
+
+    public void setCreatedDateTime(LocalDateTime createdDateTime) {
+        this.createdDateTime = createdDateTime;
+    }
+
+    public Long getIssueId() {
+        return issueId;
+    }
+
+    public void setIssueId(Long issueId) {
+        this.issueId = issueId;
+    }
+
+    public Long getUserId() {
+        return userId;
+    }
+
+    public void setUserId(Long userId) {
+        this.userId = userId;
+    }
+
+    public static class Builder {
+        private Long id;
+        private String description;
+        private LocalDateTime createdDateTime;
+        private Long issueId;
+        private Long userId;
+
+        public Builder() {}
+
+        public Builder id(Long id) {
+            this.id = id;
+            return this;
+        }
+
+        public Builder description(String description) {
+            this.description = description;
+            return this;
+        }
+
+        public Builder createdDateTime(LocalDateTime createdDateTime) {
+            this.createdDateTime = createdDateTime;
+            return this;
+        }
+
+        public Builder issuId(Long issueId) {
+            this.issueId = issueId;
+            return this;
+        }
+
+        public Builder userId(Long userId) {
+            this.userId = userId;
+            return this;
+        }
+
+        public Comment build() {
+            return new Comment(id, description, createdDateTime, issueId, userId);
+        }
+    }
+}