spring data jpa : Persistable

spring-data-jpa/src/main/java/com/example/springdatajpa/controller/MemberController.java

@@ -36,7 +36,7 @@ public class MemberController {
         return memberRepository.findAll(pageable).map(MemberDto::new);
     }
 
-    @PostConstruct
+//    @PostConstruct
     public void init() {
         for (int i = 0; i < 100; i++) {
             memberRepository.save(new Member("member" + i, i));

spring-data-jpa/src/main/java/com/example/springdatajpa/entity/Item.java

@@ -0,0 +1,40 @@
+package com.example.springdatajpa.entity;
+
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+import org.springframework.data.annotation.CreatedDate;
+import org.springframework.data.domain.Persistable;
+import org.springframework.data.jpa.domain.support.AuditingEntityListener;
+
+import javax.persistence.Entity;
+import javax.persistence.EntityListeners;
+import javax.persistence.Id;
+import java.time.LocalDateTime;
+
+@Entity
+@EntityListeners(AuditingEntityListener.class)
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+public class Item implements Persistable<String> {
+
+    // @GeneratedValue 사용하지 않을 경우 -> jpa 기본전략에 의해 persist 가 아닌 merge 수행
+    @Id
+    private String itemId;
+
+    public Item(String itemId) {
+        this.itemId = itemId;
+    }
+
+    @CreatedDate
+    private LocalDateTime createdDate;
+
+    @Override
+    public String getId() {
+        return itemId;
+    }
+
+    @Override
+    public boolean isNew() {
+        // 새로운 객체인지 판단을 생성 날짜 유무로 한다.
+        return createdDate == null;
+    }
+}

spring-data-jpa/src/main/java/com/example/springdatajpa/repository/ItemRepository.java

@@ -0,0 +1,7 @@
+package com.example.springdatajpa.repository;
+
+import com.example.springdatajpa.entity.Item;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface ItemRepository extends JpaRepository<Item, String> {
+}

spring-data-jpa/src/test/java/com/example/springdatajpa/entity/ItemTest.java

@@ -0,0 +1,21 @@
+package com.example.springdatajpa.entity;
+
+import com.example.springdatajpa.repository.ItemRepository;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+@SpringBootTest
+class ItemTest {
+
+    @Autowired
+    ItemRepository itemRepository;
+
+    @Test
+    void save() {
+        itemRepository.save(new Item("A"));
+    }
+
+}