diff --git "a/v1/backend/SPRING_LV_1_\354\275\251_\354\213\254\354\235\200_\353\215\260_\354\275\251_\353\202\234\353\213\244/src/main/java/com/example/kong/KongApplication.java" "b/v1/backend/SPRING_LV_1_\354\275\251_\354\213\254\354\235\200_\353\215\260_\354\275\251_\353\202\234\353\213\244/src/main/java/com/example/kong/KongApplication.java"
index b5ea21e..2f7072d 100644
--- "a/v1/backend/SPRING_LV_1_\354\275\251_\354\213\254\354\235\200_\353\215\260_\354\275\251_\353\202\234\353\213\244/src/main/java/com/example/kong/KongApplication.java"
+++ "b/v1/backend/SPRING_LV_1_\354\275\251_\354\213\254\354\235\200_\353\215\260_\354\275\251_\353\202\234\353\213\244/src/main/java/com/example/kong/KongApplication.java"
@@ -4,6 +4,7 @@
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 
+// 님이 있는 패키지 기준으로 컴포넌트 스캔을 시작합니다..
 @SpringBootApplication
 public class KongApplication {
 
diff --git "a/v1/backend/SPRING_LV_1_\354\275\251_\354\213\254\354\235\200_\353\215\260_\354\275\251_\353\202\234\353\213\244/src/main/java/com/example/kong/KongController.java" "b/v1/backend/SPRING_LV_1_\354\275\251_\354\213\254\354\235\200_\353\215\260_\354\275\251_\353\202\234\353\213\244/src/main/java/com/example/kong/KongController.java"
index 78474c7..16d275b 100644
--- "a/v1/backend/SPRING_LV_1_\354\275\251_\354\213\254\354\235\200_\353\215\260_\354\275\251_\353\202\234\353\213\244/src/main/java/com/example/kong/KongController.java"
+++ "b/v1/backend/SPRING_LV_1_\354\275\251_\354\213\254\354\235\200_\353\215\260_\354\275\251_\353\202\234\353\213\244/src/main/java/com/example/kong/KongController.java"
@@ -1,12 +1,17 @@
 package com.example.kong;
 
+import lombok.RequiredArgsConstructor;
 import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
 
 /* Spring Boot에서 컨트롤러는 어떻게 인식할까요? */
+@RestController //@Controller(이쪽으로 가면 View에염) + @ResponseBody(메서드 어노테이션) -> Http Response에 박아버려 View 찾지 마셈
+@RequiredArgsConstructor
 public class KongController {
 
-	private KongService kongService;
+	private final KongService kongService;
 
+	// 내장된 톰캣(Tomcat) 서버나 다른 서블릿 컨테이너 위에서 애플리케이션 실행 시 요청을 컨트롤러로 라우팅.
 	@GetMapping("/reaction")
 	public String reaction() {
 		return kongService.reactToDrink();
diff --git "a/v1/backend/SPRING_LV_1_\354\275\251_\354\213\254\354\235\200_\353\215\260_\354\275\251_\353\202\234\353\213\244/src/main/java/com/example/kong/KongService.java" "b/v1/backend/SPRING_LV_1_\354\275\251_\354\213\254\354\235\200_\353\215\260_\354\275\251_\353\202\234\353\213\244/src/main/java/com/example/kong/KongService.java"
index 27bd1ac..9231c88 100644
--- "a/v1/backend/SPRING_LV_1_\354\275\251_\354\213\254\354\235\200_\353\215\260_\354\275\251_\353\202\234\353\213\244/src/main/java/com/example/kong/KongService.java"
+++ "b/v1/backend/SPRING_LV_1_\354\275\251_\354\213\254\354\235\200_\353\215\260_\354\275\251_\353\202\234\353\213\244/src/main/java/com/example/kong/KongService.java"
@@ -3,12 +3,29 @@
 import com.example.kong.util.DrinkPrinter;
 import com.example.kong.util.DrinkProperties;
 import com.example.kong.util.Space;
+import lombok.RequiredArgsConstructor;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
 
 /* Spring Boot에서 서비스는 어떻게 인식할까요? */
+@Service // 동일하게 컴포넌트 스캔 Component 파생 어노테이션
+@RequiredArgsConstructor
 public class KongService {
 
 	/* 어떻게 주입받아야 할까요? */
-	private DrinkProperties drinkProperties;
+	/*
+	* @RequiredArgsConstructor
+	* final / @NonNull 필드들에 대해 생성자 자동 생성
+	* DI를 위해 사용, final 키워드가 붙은 모든 필드를 인자로 받아 의존성 주입
+	* 아래의 긴 코드들을 Lombok이 깨깟하게 정리
+	*
+	* @Autowired
+	* public KongService(DrinkProperties drinkProperties) {
+	* 	this.drinkProperties = drinkProperties;
+	* }
+	* */
+	private final DrinkProperties drinkProperties;
+
 
 	// 냄새가 나는 코드지만 예제를 위한 부분이니 신경쓰지 말아주세요..
 	public String reactToDrink() {
diff --git "a/v1/backend/SPRING_LV_1_\354\275\251_\354\213\254\354\235\200_\353\215\260_\354\275\251_\353\202\234\353\213\244/src/main/java/com/example/kong/util/DrinkProperties.java" "b/v1/backend/SPRING_LV_1_\354\275\251_\354\213\254\354\235\200_\353\215\260_\354\275\251_\353\202\234\353\213\244/src/main/java/com/example/kong/util/DrinkProperties.java"
index 82e67f8..e7ecea8 100644
--- "a/v1/backend/SPRING_LV_1_\354\275\251_\354\213\254\354\235\200_\353\215\260_\354\275\251_\353\202\234\353\213\244/src/main/java/com/example/kong/util/DrinkProperties.java"
+++ "b/v1/backend/SPRING_LV_1_\354\275\251_\354\213\254\354\235\200_\353\215\260_\354\275\251_\353\202\234\353\213\244/src/main/java/com/example/kong/util/DrinkProperties.java"
@@ -4,10 +4,28 @@
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Component;
 
+/*
+* 1. 클래스가 Spring Container에 의해 인스턴스화
+* 2. Spring Bean으로 관리되어야한다 명시화
+*
+* -> 컴포넌트 스캔, Spring Context에 bean으로 등록 및 생명주기 관리
+* @Autowired 같은 어노테이션을 통해 의존성 주입 가능
+* */
 @Component // 가 뭘까요?
-@Getter
+@Getter // Lombok -> Getter 선언. 외부에서도 값을 읽을 수 있다
 public class DrinkProperties {
 
+	/*
+	* 프로퍼티 파일, 환경 변수, 커맨드 라인 인자 등에서 값을 주입
+	* application.properties 또는 application.yml 파일에 정의된 프로퍼티 값을 클래스의 필드에 바인딩
+	*
+	* Spring이 관리하는 빈의 초기화 시점에서 applicaiont~ 에서 해당 값을 서치, 계층별로 나타내고 있다.
+	* 	-> 클래스 내부 필드에 바인딩(drink에 주입)
+	*
+	* BeanCreationException(생성할랬더니 그런거 없는디요?에러)를 방지하기 위해
+	* @Value("${spring.kong.what-kind-of-drink:coke}")
+	* 이런 식으로 default 값을 정해줄 수도 있다네용
+	* */
 	@Value("${spring.kong.what-kind-of-drink}") // 는 어떻게 값을 가져오는 걸까요?
 	private String drink;
 }
diff --git "a/v1/backend/SPRING_LV_1_\354\275\251_\354\213\254\354\235\200_\353\215\260_\354\275\251_\353\202\234\353\213\244/src/main/resources/application.yml" "b/v1/backend/SPRING_LV_1_\354\275\251_\354\213\254\354\235\200_\353\215\260_\354\275\251_\353\202\234\353\213\244/src/main/resources/application.yml"
index d1b299e..70f224e 100644
--- "a/v1/backend/SPRING_LV_1_\354\275\251_\354\213\254\354\235\200_\353\215\260_\354\275\251_\353\202\234\353\213\244/src/main/resources/application.yml"
+++ "b/v1/backend/SPRING_LV_1_\354\275\251_\354\213\254\354\235\200_\353\215\260_\354\275\251_\353\202\234\353\213\244/src/main/resources/application.yml"
@@ -1,3 +1,3 @@
 spring:
   kong:
-   what-kind-of-drink: 'coffee'
\ No newline at end of file
+   what-kind-of-drink: 'coke'
\ No newline at end of file
diff --git "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/LentController.java" "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/LentController.java"
deleted file mode 100644
index be46233..0000000
--- "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/LentController.java"
+++ /dev/null
@@ -1,14 +0,0 @@
-package com.example.lent;
-
-import com.example.lent.dto.LentRequest;
-import com.example.lent.dto.LentResponse;
-
-/*컨트롤러는 뭘까요?*/
-/*컨트롤러는 왜 인터페이스가 없어도 될까요?*/
-public class LentController {
-	private LentService lentService;
-
-	public LentResponse lent(LentRequest request) {
-		return null;
-	}
-}
diff --git "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/LentHistoryRepository.java" "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/LentHistoryRepository.java"
deleted file mode 100644
index 534a121..0000000
--- "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/LentHistoryRepository.java"
+++ /dev/null
@@ -1,11 +0,0 @@
-package com.example.lent;
-
-import com.example.lent.domain.LentHistory;
-
-import java.util.List;
-
-public interface LentHistoryRepository {
-	LentHistory save(LentHistory lentHistory);
-
-	List<LentHistory> findAll();
-}
diff --git "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/LentHistoryRepositoryImpl.java" "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/LentHistoryRepositoryImpl.java"
deleted file mode 100644
index 96cff00..0000000
--- "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/LentHistoryRepositoryImpl.java"
+++ /dev/null
@@ -1,23 +0,0 @@
-package com.example.lent;
-
-import com.example.lent.domain.LentHistory;
-
-import java.util.ArrayList;
-import java.util.List;
-
-/*리포지토리는 뭘까요?*/
-public class LentHistoryRepositoryImpl implements LentHistoryRepository {
-	private static Long ID_SEQUENCE = 1L;
-	/*실제 DB를 사용하지 않으므로 내부 Collection으로 대체합니다. - Collection이 뭘까요?*/
-	private static final List<LentHistory> TABLE = new ArrayList<>();
-
-	@Override
-	public LentHistory save(LentHistory lentHistory) {
-		return null;
-	}
-
-	@Override
-	public List<LentHistory> findAll() {
-		return null;
-	}
-}
diff --git "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/LentServiceImpl.java" "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/LentServiceImpl.java"
deleted file mode 100644
index 4ecff32..0000000
--- "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/LentServiceImpl.java"
+++ /dev/null
@@ -1,12 +0,0 @@
-package com.example.lent;
-
-import com.example.lent.dto.LentRequest;
-import com.example.lent.dto.LentResponse;
-
-/*서비스는 뭘까요?*/
-public class LentServiceImpl implements LentService {
-	@Override
-	public LentResponse lent(LentRequest request) {
-		return null;
-	}
-}
diff --git "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/controller/LentController.java" "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/controller/LentController.java"
new file mode 100644
index 0000000..a9965ea
--- /dev/null
+++ "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/controller/LentController.java"
@@ -0,0 +1,19 @@
+package com.example.lent.controller;
+
+import com.example.lent.dto.LentRequest;
+import com.example.lent.dto.LentResponse;
+import com.example.lent.service.LentService;
+
+/*컨트롤러는 뭘까요?*/
+/*컨트롤러는 왜 인터페이스가 없어도 될까요?*/
+public class LentController {
+    private final LentService lentService;
+
+    public LentController(LentService lentService) {
+        this.lentService = lentService;
+    }
+
+    public LentResponse lent(LentRequest request) {
+        return lentService.lent(request);
+    }
+}
diff --git "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/domain/Cabinet.java" "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/domain/Cabinet.java"
index d86aa42..9dc3396 100644
--- "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/domain/Cabinet.java"
+++ "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/domain/Cabinet.java"
@@ -1,21 +1,23 @@
 package com.example.lent.domain;
 
-import lombok.AllArgsConstructor;
 import lombok.Getter;
-import lombok.RequiredArgsConstructor;
 
 /*Entity가 뭘까요?*/
 @Getter
 public class Cabinet {
-	private Long cabinetId;
-	private CabinetStatus cabinetStatus;
+    private Long cabinetId;
+    private CabinetStatus cabinetStatus;
 
-	public Cabinet(CabinetStatus status) {
-		this.cabinetId = null;
-		this.cabinetStatus = status;
-	}
+    public Cabinet(CabinetStatus status) {
+        this.cabinetId = null;
+        this.cabinetStatus = status;
+    }
 
-	public void id(Long id) {
-		this.cabinetId = id;
-	}
+    public void id(Long id) {
+        this.cabinetId = id;
+    }
+
+    public void setStatus(CabinetStatus cabinetStatus) {
+        this.cabinetStatus = cabinetStatus;
+    }
 }
diff --git "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/domain/LentHistory.java" "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/domain/LentHistory.java"
index d7f3169..d4fb3b1 100644
--- "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/domain/LentHistory.java"
+++ "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/domain/LentHistory.java"
@@ -1,26 +1,29 @@
 package com.example.lent.domain;
 
-import lombok.AllArgsConstructor;
-import lombok.Getter;
-import lombok.RequiredArgsConstructor;
-
 import java.time.LocalDateTime;
+import lombok.Getter;
 
 /*Entity가 뭘까요?*/
 @Getter
 public class LentHistory {
-	private Long lentHistoryId;
-	private Long userId;
-	private Long cabinetId;
-	private String lentUserName;
-	private LocalDateTime createdAt;
-	private LocalDateTime expiredAt;
+    private Long lentHistoryId;
+    private Long userId;
+    private Long cabinetId;
+    private String lentUserName;
+    private LocalDateTime createdAt;
+    private LocalDateTime expiredAt;
+
+    public LentHistory(Long cabinetId, Long userId, String lentUserName, LocalDateTime createdAt,
+                       LocalDateTime expiredAt) {
+        this.cabinetId = cabinetId;
+        this.userId = userId;
+        this.lentUserName = lentUserName;
+        this.createdAt = createdAt;
+        this.expiredAt = expiredAt;
+    }
+
+    public void id(Long id) {
+        this.lentHistoryId = id;
+    }
 
-	public LentHistory(Long cabinetId, Long userId, String lentUserName, LocalDateTime createdAt, LocalDateTime expiredAt) {
-		this.cabinetId = cabinetId;
-		this.userId = userId;
-		this.lentUserName = lentUserName;
-		this.createdAt = createdAt;
-		this.expiredAt = expiredAt;
-	}
 }
diff --git "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/dto/LentResponse.java" "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/dto/LentResponse.java"
index dfc04a7..5b0639b 100644
--- "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/dto/LentResponse.java"
+++ "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/dto/LentResponse.java"
@@ -1,18 +1,16 @@
 package com.example.lent.dto;
 
+import java.time.LocalDateTime;
 import lombok.AllArgsConstructor;
 import lombok.Getter;
-import lombok.RequiredArgsConstructor;
-
-import java.time.LocalDateTime;
 
 /*DTO가 뭘까요?*/
 @AllArgsConstructor
 @Getter
 public class LentResponse {
-	private Long lentHistoryId;
-	private Long cabinetId;
-	private String userName;
-	private LocalDateTime lentAt;
-	private LocalDateTime expiredAt;
+    private Long lentHistoryId;
+    private Long cabinetId;
+    private String userName;
+    private LocalDateTime lentAt;
+    private LocalDateTime expiredAt;
 }
diff --git "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/repository/LentHistoryRepository.java" "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/repository/LentHistoryRepository.java"
new file mode 100644
index 0000000..dcbd781
--- /dev/null
+++ "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/repository/LentHistoryRepository.java"
@@ -0,0 +1,10 @@
+package com.example.lent.repository;
+
+import com.example.lent.domain.LentHistory;
+import java.util.List;
+
+public interface LentHistoryRepository {
+    LentHistory save(LentHistory lentHistory);
+
+    List<LentHistory> findAll();
+}
diff --git "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/repository/LentHistoryRepositoryImpl.java" "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/repository/LentHistoryRepositoryImpl.java"
new file mode 100644
index 0000000..53e319d
--- /dev/null
+++ "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/repository/LentHistoryRepositoryImpl.java"
@@ -0,0 +1,53 @@
+package com.example.lent.repository;
+
+import com.example.lent.domain.LentHistory;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/*리포지토리는 뭘까요?*/
+public class LentHistoryRepositoryImpl implements LentHistoryRepository {
+    private static Long ID_SEQUENCE = 1L;
+    /*실제 DB를 사용하지 않으므로 내부 Collection으로 대체합니다. - Collection이 뭘까요?*/
+    private static final List<LentHistory> TABLE = new ArrayList<>();
+
+    /**
+     * @param lentHistory cabinetId, userId, lentUserName, createAt, expiredAt
+     * @return
+     */
+    @Override
+    public LentHistory save(LentHistory lentHistory) {
+        // update
+        if (lentHistory.getLentHistoryId() != null) {
+            TABLE.removeIf(history -> history.getLentHistoryId().equals(lentHistory.getLentHistoryId()));
+            TABLE.add(lentHistory);
+            return lentHistory;
+        }
+        // new
+        lentHistory.id(ID_SEQUENCE++);
+        TABLE.add(lentHistory);
+        return lentHistory;
+    }
+
+    @Override
+    public List<LentHistory> findAll() {
+        /*
+         * unmodifiable vs copyOf vs new ArrayList<>(TABLE)
+         *
+         * unmodifiable~
+         * 복사본의 추가, 삭제, 갱신 등의 변경 작업은 불가.
+         * 사본 리스트를 변경하려고 하면 UnsupportedOperationException이 발생
+         * 원본 변경 시 복사본도 변경
+         *
+         * copyOf~
+         * 복사본의 추가, 삭제, 갱신 등의 변경 작업은 불가.
+         * 사본 리스트를 변경하려고 하면 UnsupportedOperationException이 발생
+         * 원본 변경해도 복사본은 독립적
+         *
+         * new Array~
+         * 변경 가능, 복사본은 독립적
+         * */
+        return Collections.unmodifiableList(TABLE);
+    }
+
+}
diff --git "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/LentService.java" "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/service/LentService.java"
similarity index 60%
rename from "v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/LentService.java"
rename to "v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/service/LentService.java"
index 1892b70..0c07095 100644
--- "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/LentService.java"
+++ "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/service/LentService.java"
@@ -1,8 +1,8 @@
-package com.example.lent;
+package com.example.lent.service;
 
 import com.example.lent.dto.LentRequest;
 import com.example.lent.dto.LentResponse;
 
 public interface LentService {
-	LentResponse lent(LentRequest request);
+    LentResponse lent(LentRequest request);
 }
diff --git "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/service/LentServiceImpl.java" "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/service/LentServiceImpl.java"
new file mode 100644
index 0000000..e9c7724
--- /dev/null
+++ "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/service/LentServiceImpl.java"
@@ -0,0 +1,78 @@
+package com.example.lent.service;
+
+import com.example.lent.domain.Cabinet;
+import com.example.lent.domain.CabinetStatus;
+import com.example.lent.domain.LentHistory;
+import com.example.lent.domain.User;
+import com.example.lent.dto.LentRequest;
+import com.example.lent.dto.LentResponse;
+import com.example.lent.repository.LentHistoryRepository;
+import com.example.lent.testutil.CabinetRepository;
+import com.example.lent.testutil.UserRepository;
+import java.util.List;
+
+/*서비스는 뭘까요?*/
+public class LentServiceImpl implements LentService {
+    private static final int LENT_DAYS = 31;
+    private final LentHistoryRepository lentHistoryRepository;
+    private final CabinetRepository cabinetRepository;
+    private final UserRepository userRepository;
+
+    public LentServiceImpl(LentHistoryRepository lentHistoryRepository, CabinetRepository cabinetRepository,
+                           UserRepository userRepository) {
+        this.lentHistoryRepository = lentHistoryRepository;
+        this.cabinetRepository = cabinetRepository;
+        this.userRepository = userRepository;
+    }
+
+    /**
+     * @param request -> cabinetId, userId, localDateTime
+     * @return LentResponse -> historyId, cabinetId, usrName, lentAt, expiredAt
+     */
+    @Override
+    public LentResponse lent(LentRequest request) {
+        Cabinet cabinet = cabinetRepository.findById(request.getCabinetId());
+        validateCabinetStatus(cabinet);
+
+        User user = userRepository.findById(request.getUserId());
+        validateUserStatus(user);
+
+        LentHistory lentHistory = new LentHistory(cabinet.getCabinetId(), user.getUserId(), user.getName(),
+                request.getCreatedAt(), request.getCreatedAt().plusDays(LENT_DAYS));
+        cabinet.setStatus(CabinetStatus.FULL);
+        cabinetRepository.save(cabinet);
+
+        if (!isAlreadyHasLentUser(user)) {
+            lentHistoryRepository.save(lentHistory);
+        }
+
+        return new LentResponse(lentHistory.getLentHistoryId(), lentHistory.getCabinetId(),
+                lentHistory.getLentUserName(), lentHistory.getCreatedAt(), lentHistory.getExpiredAt());
+    }
+
+    private boolean isAlreadyHasLentUser(User user) {
+        List<LentHistory> lentHistories = lentHistoryRepository.findAll();
+        boolean isAlreadyLentUser = lentHistories.stream()
+                .anyMatch(history -> history.getUserId().equals(user.getUserId()));
+        if (isAlreadyLentUser) {
+            throw new RuntimeException("이미 대여 중인 유저입니다.");
+        }
+        return false;
+    }
+
+    /**
+     * 궁금한 점 -> 1. 왜 interface를 사용할까? 2.Repository 내에서 Exception을 발생시키는 이유?
+     */
+    private void validateUserStatus(User user) {
+        if (user.isBanned()) {
+            throw new RuntimeException("사용 정지상태인 유저입니다.");
+        }
+    }
+
+    private void validateCabinetStatus(Cabinet cabinet) {
+        if (cabinet.getCabinetStatus() == CabinetStatus.FULL) {
+            throw new RuntimeException("이미 사용 중인 사물함입니다.");
+        }
+    }
+
+}
diff --git "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/testutil/CabinetRepository.java" "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/testutil/CabinetRepository.java"
index 1c98af8..e276de4 100644
--- "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/testutil/CabinetRepository.java"
+++ "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/main/java/com/example/lent/testutil/CabinetRepository.java"
@@ -1,28 +1,34 @@
 package com.example.lent.testutil;
 
 import com.example.lent.domain.Cabinet;
-
 import java.util.ArrayList;
 import java.util.List;
 
 public class CabinetRepository {
-	private static Long ID_SEQUENCE = 1L;
-	/*실제 DB를 사용하지 않으므로 내부 Collection으로 대체합니다. - Collection이 뭘까요?*/
-	private final List<Cabinet> TABLE = new ArrayList<>();
+    private static Long ID_SEQUENCE = 1L;
+    /*실제 DB를 사용하지 않으므로 내부 Collection으로 대체합니다. - Collection이 뭘까요?*/
+    private final List<Cabinet> TABLE = new ArrayList<>();
+
+    /*왜 copyOf를 사용할까요?*/
+    public List<Cabinet> findAll() {
+        return List.copyOf(TABLE);
+    }
 
-	/*왜 copyOf를 사용할까요?*/
-	public List<Cabinet> findAll() {
-		return List.copyOf(TABLE);
-	}
+    public Cabinet findById(Long id) {
+        return TABLE.stream()
+                .filter(c -> c.getCabinetId().equals(id))
+                .findFirst()
+                .orElseThrow(() -> new RuntimeException("존재하지 않는 Cabinet입니다."));
+    }
 
-	public Cabinet save(Cabinet cabinet) {
-		if (cabinet.getCabinetId() != null) {
-			TABLE.removeIf(c -> c.getCabinetId().equals(cabinet.getCabinetId()));
-			TABLE.add(cabinet);
-			return cabinet;
-		}
-		cabinet.id(ID_SEQUENCE++);
-		TABLE.add(cabinet);
-		return cabinet;
-	}
+    public Cabinet save(Cabinet cabinet) {
+        if (cabinet.getCabinetId() != null) {
+            TABLE.removeIf(c -> c.getCabinetId().equals(cabinet.getCabinetId()));
+            TABLE.add(cabinet);
+            return cabinet;
+        }
+        cabinet.id(ID_SEQUENCE++);
+        TABLE.add(cabinet);
+        return cabinet;
+    }
 }
diff --git "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/test/java/com/example/lent/LentTest.java" "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/test/java/com/example/lent/LentTest.java"
index 867c614..68aafdd 100644
--- "a/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/test/java/com/example/lent/LentTest.java"
+++ "b/v1/backend/SPRING_LV_2_\352\260\234\353\205\270\353\213\265_3\352\263\204\354\270\265/src/test/java/com/example/lent/LentTest.java"
@@ -1,117 +1,125 @@
 package com.example.lent;
 
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+import com.example.lent.controller.LentController;
 import com.example.lent.domain.Cabinet;
 import com.example.lent.domain.CabinetStatus;
 import com.example.lent.domain.LentHistory;
 import com.example.lent.domain.User;
 import com.example.lent.dto.LentRequest;
 import com.example.lent.dto.LentResponse;
+import com.example.lent.repository.LentHistoryRepository;
+import com.example.lent.repository.LentHistoryRepositoryImpl;
+import com.example.lent.service.LentService;
+import com.example.lent.service.LentServiceImpl;
 import com.example.lent.testutil.CabinetRepository;
 import com.example.lent.testutil.UserRepository;
+import java.time.LocalDateTime;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
-import java.time.LocalDateTime;
-
-import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.assertThatThrownBy;
-
 
 public class LentTest {
 
-	private LentController lentController;
-	private LentService lentService;
-	private UserRepository userRepository;
-	private LentHistoryRepository lentHistoryRepository;
-	private CabinetRepository cabinetRepository;
-
-	// 내부 구현을 작성하신 후에, 아래의 주석을 해제해주세요. - 의존성 주입이 뭘까요?
-	@BeforeEach
-	public void setUp() {
-		userRepository = new UserRepository();
-		cabinetRepository = new CabinetRepository();
-		lentHistoryRepository = new LentHistoryRepositoryImpl();
-		lentService = new LentServiceImpl(/*lentHistoryRepository, cabinetRepository, userRepository*/);
-		lentController = new LentController(/*lentService*/);
-	}
-
-	@DisplayName("지금부터 대여를 시작한다.")
-	@Test
-	void 테스트를_읽어보세요() {
-		// given
-		LocalDateTime now = LocalDateTime.now();
-		Long ignoreId = 9999L;
-		boolean banned = true;
-		boolean notBanned = false;
-
-		User wchae = createAndSave("wchae", notBanned);
-		User daewoole = createAndSave("daewoole", banned);
-		User jpark2 = createAndSave("jpark2", notBanned);
-
-		Cabinet cabinet1 = createAndSave(CabinetStatus.FULL);
-		Cabinet cabinet2 = createAndSave(CabinetStatus.AVAILABLE);
-		Cabinet cabinet3 = createAndSave(CabinetStatus.AVAILABLE);
-
-		createAndSaveLentHistory(jpark2, cabinet1, now.minusDays(10), 31);
-		assertThat(lentHistoryRepository.findAll().size()).isEqualTo(1); // NPE가 난다면 무슨 이유일까요?
-
-		LentRequest wrongRequestCabinetAlreadyOccupied = new LentRequest(cabinet1.getCabinetId(), wchae.getUserId(), now);
-		LentRequest wrongRequestUserAlreadyHasLent = new LentRequest(cabinet2.getCabinetId(), jpark2.getUserId(), now);
-		LentRequest wrongRequestUserBanned = new LentRequest(cabinet3.getCabinetId(), daewoole.getUserId(), now);
-		LentRequest validRequestByWchae = new LentRequest(cabinet3.getCabinetId(), wchae.getUserId(), now);
-
-
-		// 익셉션은 어떻게 throw 할까요?
-		assertThatThrownBy(() -> lentController.lent(wrongRequestCabinetAlreadyOccupied))
-				.isInstanceOf(RuntimeException.class)
-				.hasMessage("이미 사용 중인 사물함입니다.");
-		assertThatThrownBy(() -> lentController.lent(wrongRequestUserAlreadyHasLent))
-				.isInstanceOf(RuntimeException.class)
-				.hasMessage("이미 대여 중인 유저입니다.");
-		assertThatThrownBy(() -> lentController.lent(wrongRequestUserBanned))
-				.isInstanceOf(RuntimeException.class)
-				.hasMessage("사용 정지상태인 유저입니다.");
-		LentResponse response = lentController.lent(validRequestByWchae);
-
-		// 컨트롤러 응답 검사
-		assertThat(response.getLentHistoryId()).isNotNull();
-		assertThat(response.getCabinetId()).isEqualTo(validRequestByWchae.getCabinetId());
-		assertThat(response.getUserName()).isEqualTo(wchae.getName());
-		assertThat(response.getLentAt()).isEqualTo(validRequestByWchae.getCreatedAt());
-		assertThat(response.getExpiredAt()).isEqualTo(validRequestByWchae.getCreatedAt().plusDays(31));
-
-		// 대여기록 검사
-		LentHistory wchaeHistory = lentHistoryRepository.findAll().stream()
-				.filter(e -> e.getLentUserName().equals(wchae.getName()))
-				.findAny().orElseThrow(() -> new RuntimeException("테스트 실패 !! 대여 기록이 없습니다!!"));
-		assertThat(wchaeHistory.getCabinetId()).isEqualTo(validRequestByWchae.getCabinetId());
-		assertThat(wchaeHistory.getLentUserName()).isEqualTo(wchae.getName());
-		assertThat(wchaeHistory.getCreatedAt()).isEqualTo(validRequestByWchae.getCreatedAt());
-		assertThat(wchaeHistory.getExpiredAt()).isEqualTo(validRequestByWchae.getCreatedAt().plusDays(31));
-
-		// 대여된 사물함 검사
-		Cabinet cabinet = cabinetRepository.findAll().stream()
-				.filter(e -> e.getCabinetId().equals(wchaeHistory.getCabinetId()))
-				.findAny().orElseThrow(() -> new RuntimeException("테스트 실패 !! 사물함이 없습니다!!"));
-		assertThat(cabinet.getCabinetStatus()).isEqualTo(CabinetStatus.FULL);
-	}
-
-	private Cabinet createAndSave(CabinetStatus cabinetStatus) {
-		Cabinet cabinet = new Cabinet(cabinetStatus);
-		cabinetRepository.save(cabinet);
-		return cabinet;
-	}
-
-	private User createAndSave(String name, boolean isBanned) {
-		User user = new User(name, isBanned);
-		userRepository.save(user);
-		return user;
-	}
-
-	private LentHistory createAndSaveLentHistory(User user, Cabinet cabinet, LocalDateTime now, int days) {
-		LentHistory lentHistory = new LentHistory(user.getUserId(), cabinet.getCabinetId(), user.getName(), now, now.plusDays(days));
-		lentHistoryRepository.save(lentHistory);
-		return lentHistory;
-	}
+    private LentController lentController;
+    private LentService lentService;
+    private UserRepository userRepository;
+    private LentHistoryRepository lentHistoryRepository;
+    private CabinetRepository cabinetRepository;
+
+    // 내부 구현을 작성하신 후에, 아래의 주석을 해제해주세요. - 의존성 주입이 뭘까요?
+    @BeforeEach
+    public void setUp() {
+        userRepository = new UserRepository();
+        cabinetRepository = new CabinetRepository();
+        lentHistoryRepository = new LentHistoryRepositoryImpl();
+        lentService = new LentServiceImpl(lentHistoryRepository, cabinetRepository, userRepository);
+        lentController = new LentController(lentService);
+    }
+
+    @DisplayName("지금부터 대여를 시작한다.")
+    @Test
+    void 테스트를_읽어보세요() {
+        // given
+        LocalDateTime now = LocalDateTime.now();
+        Long ignoreId = 9999L;
+        boolean banned = true;
+        boolean notBanned = false;
+
+        User wchae = createAndSave("wchae", notBanned);
+        User daewoole = createAndSave("daewoole", banned);
+        User jpark2 = createAndSave("jpark2", notBanned);
+
+        Cabinet cabinet1 = createAndSave(CabinetStatus.FULL);
+        Cabinet cabinet2 = createAndSave(CabinetStatus.AVAILABLE);
+        Cabinet cabinet3 = createAndSave(CabinetStatus.AVAILABLE);
+
+        createAndSaveLentHistory(jpark2, cabinet1, now.minusDays(10), 31);
+        assertThat(lentHistoryRepository.findAll().size()).isEqualTo(1); // NPE가 난다면 무슨 이유일까요?
+
+        LentRequest wrongRequestCabinetAlreadyOccupied = new LentRequest(cabinet1.getCabinetId(), wchae.getUserId(),
+                now);
+        LentRequest wrongRequestUserAlreadyHasLent = new LentRequest(cabinet2.getCabinetId(), jpark2.getUserId(), now);
+        LentRequest wrongRequestUserBanned = new LentRequest(cabinet3.getCabinetId(), daewoole.getUserId(), now);
+        LentRequest validRequestByWchae = new LentRequest(cabinet3.getCabinetId(), wchae.getUserId(), now);
+
+        // 익셉션은 어떻게 throw 할까요?
+        assertThatThrownBy(() -> lentController.lent(wrongRequestCabinetAlreadyOccupied))
+                .isInstanceOf(RuntimeException.class)
+                .hasMessage("이미 사용 중인 사물함입니다.");
+        assertThatThrownBy(() -> lentController.lent(wrongRequestUserAlreadyHasLent))
+                .isInstanceOf(RuntimeException.class)
+                .hasMessage("이미 대여 중인 유저입니다.");
+        assertThatThrownBy(() -> lentController.lent(wrongRequestUserBanned))
+                .isInstanceOf(RuntimeException.class)
+                .hasMessage("사용 정지상태인 유저입니다.");
+        LentResponse response = lentController.lent(validRequestByWchae);
+
+        // 컨트롤러 응답 검사
+        assertThat(response.getLentHistoryId()).isNotNull();
+        assertThat(response.getCabinetId()).isEqualTo(validRequestByWchae.getCabinetId());
+        assertThat(response.getUserName()).isEqualTo(wchae.getName());
+        assertThat(response.getLentAt()).isEqualTo(validRequestByWchae.getCreatedAt());
+        assertThat(response.getExpiredAt()).isEqualTo(validRequestByWchae.getCreatedAt().plusDays(31));
+
+        // 대여기록 검사
+        LentHistory wchaeHistory =
+                lentHistoryRepository.findAll().stream()
+                        .filter(e -> e.getLentUserName().equals(wchae.getName()))
+                        .findAny()
+                        .orElseThrow(() -> new RuntimeException("테스트 실패 !! 대여 기록이 없습니다!!"));
+        assertThat(wchaeHistory.getCabinetId()).isEqualTo(validRequestByWchae.getCabinetId());
+        assertThat(wchaeHistory.getLentUserName()).isEqualTo(wchae.getName());
+        assertThat(wchaeHistory.getCreatedAt()).isEqualTo(validRequestByWchae.getCreatedAt());
+        assertThat(wchaeHistory.getExpiredAt()).isEqualTo(validRequestByWchae.getCreatedAt().plusDays(31));
+
+        // 대여된 사물함 검사
+        Cabinet cabinet = cabinetRepository.findAll().stream()
+                .filter(e -> e.getCabinetId().equals(wchaeHistory.getCabinetId()))
+                .findAny().orElseThrow(() -> new RuntimeException("테스트 실패 !! 사물함이 없습니다!!"));
+        assertThat(cabinet.getCabinetStatus()).isEqualTo(CabinetStatus.FULL);
+    }
+
+    private Cabinet createAndSave(CabinetStatus cabinetStatus) {
+        Cabinet cabinet = new Cabinet(cabinetStatus);
+        cabinetRepository.save(cabinet);
+        return cabinet;
+    }
+
+    private User createAndSave(String name, boolean isBanned) {
+        User user = new User(name, isBanned);
+        userRepository.save(user);
+        return user;
+    }
+
+    //의도.. 된건가요 찾느라 눈알 빠졌습니다 감사합니다
+    private LentHistory createAndSaveLentHistory(User user, Cabinet cabinet, LocalDateTime now, int days) {
+        LentHistory lentHistory = new LentHistory(cabinet.getCabinetId(), user.getUserId(), user.getName(), now,
+                now.plusDays(days));
+        lentHistoryRepository.save(lentHistory);
+        return lentHistory;
+    }
 }
diff --git "a/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/build.gradle" "b/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/build.gradle"
index 52fd554..ce0eab4 100644
--- "a/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/build.gradle"
+++ "b/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/build.gradle"
@@ -26,6 +26,11 @@ dependencies {
     compileOnly 'org.projectlombok:lombok'
     annotationProcessor 'org.projectlombok:lombok'
     testImplementation 'org.springframework.boot:spring-boot-starter-test'
+    //JPA
+    implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
+
+    // mariadb 의존성 추가
+    runtimeOnly 'org.mariadb.jdbc:mariadb-java-client:2.7.9'
 }
 
 tasks.named('test') {
diff --git "a/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/docker-compose.yml" "b/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/docker-compose.yml"
index 7e40108..5baf0b1 100644
--- "a/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/docker-compose.yml"
+++ "b/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/docker-compose.yml"
@@ -6,7 +6,7 @@ services:
     restart: always
     environment:
       MARIADB_ROOT_USER: root
-      MARIADB_ROOT_PASSWORD: example
+      MARIADB_ROOT_PASSWORD: Abcd123@
       MARIADB_DATABASE: test
     ports:
-      - "3306:3306"
\ No newline at end of file
+      - "3306:3306"
diff --git "a/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/MovieRepository.java" "b/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/MovieRepository.java"
deleted file mode 100644
index a1a811c..0000000
--- "a/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/MovieRepository.java"
+++ /dev/null
@@ -1,13 +0,0 @@
-package com.example.dongglee;
-
-import com.example.dongglee.domain.Movie;
-import org.springframework.stereotype.Repository;
-
-import java.util.List;
-
-@Repository
-public interface MovieRepository {
-	List<Movie> findAll();
-
-	Movie save(Movie movie);
-}
diff --git "a/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/MovieService.java" "b/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/MovieService.java"
deleted file mode 100644
index 7ce740d..0000000
--- "a/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/MovieService.java"
+++ /dev/null
@@ -1,29 +0,0 @@
-package com.example.dongglee;
-
-import com.example.dongglee.domain.Movie;
-import com.example.dongglee.dto.MovieCreateRequestDto;
-import lombok.RequiredArgsConstructor;
-import org.springframework.stereotype.Service;
-
-import java.util.List;
-
-@Service
-@RequiredArgsConstructor
-public class MovieService {
-
-	private final MovieRepository movieRepository;
-
-	public List<Movie> getAllMovies() {
-		return movieRepository.findAll();
-	}
-
-	public Movie createMovie(MovieCreateRequestDto dto) {
-		Movie movie = Movie.builder()
-				.director(dto.getDirector())
-				.title(dto.getTitle())
-				.filmedAt(dto.getFilmedAt())
-				.build();
-
-		return movieRepository.save(movie);
-	}
-}
diff --git "a/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/MovieController.java" "b/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/controller/MovieController.java"
similarity index 58%
rename from "v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/MovieController.java"
rename to "v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/controller/MovieController.java"
index d2a65f8..d547bc8 100644
--- "a/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/MovieController.java"
+++ "b/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/controller/MovieController.java"
@@ -1,29 +1,29 @@
-package com.example.dongglee;
+package com.example.dongglee.controller;
 
 import com.example.dongglee.domain.Movie;
 import com.example.dongglee.dto.MovieCreateRequestDto;
+import com.example.dongglee.service.MovieService;
+import java.util.List;
 import lombok.RequiredArgsConstructor;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 
-import java.util.List;
-
 @RestController
 @RequestMapping("/movies")
 @RequiredArgsConstructor
 public class MovieController {
 
-	private final MovieService movieService;
+    private final MovieService movieService;
 
-	@GetMapping
-	public List<Movie> getMovie() {
-		return movieService.getAllMovies();
-	}
+    @GetMapping
+    public List<Movie> getMovie() {
+        return movieService.getAllMovies();
+    }
 
-	@PostMapping
-	public Movie createMovie(MovieCreateRequestDto dto) {
-		return movieService.createMovie(dto);
-	}
+    @PostMapping
+    public Movie createMovie(MovieCreateRequestDto dto) {
+        return movieService.createMovie(dto);
+    }
 }
diff --git "a/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/domain/Movie.java" "b/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/domain/Movie.java"
index b6db6e3..813b9ee 100644
--- "a/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/domain/Movie.java"
+++ "b/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/domain/Movie.java"
@@ -1,15 +1,31 @@
 package com.example.dongglee.domain;
 
-import lombok.Builder;
-import lombok.Getter;
-
+import com.example.dongglee.dto.MovieCreateRequestDto;
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.Id;
 import java.time.LocalDateTime;
+import lombok.Getter;
 
-@Builder
+@Entity
 @Getter
 public class Movie {
-	private Long id;
-	private String director;
-	private String title;
-	private LocalDateTime filmedAt;
+    @Id
+    @GeneratedValue
+    @Column(name = "movie_id")
+    private Long id;
+
+    private String director;
+    private String title;
+    private LocalDateTime filmedAt;
+
+    public static Movie from(MovieCreateRequestDto dto) {
+        Movie movie = new Movie();
+
+        movie.director = dto.getDirector();
+        movie.title = dto.getTitle();
+        movie.filmedAt = dto.getFilmedAt();
+        return movie;
+    }
 }
diff --git "a/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/repository/MovieRepository.java" "b/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/repository/MovieRepository.java"
new file mode 100644
index 0000000..f378496
--- /dev/null
+++ "b/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/repository/MovieRepository.java"
@@ -0,0 +1,10 @@
+package com.example.dongglee.repository;
+
+import com.example.dongglee.domain.Movie;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface MovieRepository extends JpaRepository<Movie, Long> {
+
+}
diff --git "a/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/service/MovieService.java" "b/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/service/MovieService.java"
new file mode 100644
index 0000000..88c4361
--- /dev/null
+++ "b/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/java/com/example/dongglee/service/MovieService.java"
@@ -0,0 +1,25 @@
+package com.example.dongglee.service;
+
+import com.example.dongglee.domain.Movie;
+import com.example.dongglee.dto.MovieCreateRequestDto;
+import com.example.dongglee.repository.MovieRepository;
+import java.util.List;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+
+@Service
+@RequiredArgsConstructor
+public class MovieService {
+
+    private final MovieRepository movieRepository;
+
+    public List<Movie> getAllMovies() {
+        return movieRepository.findAll();
+    }
+
+    public Movie createMovie(MovieCreateRequestDto dto) {
+        Movie movie = Movie.from(dto);
+
+        return movieRepository.save(movie);
+    }
+}
diff --git "a/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/resources/application.yml" "b/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/resources/application.yml"
index 1114f65..7936260 100644
--- "a/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/resources/application.yml"
+++ "b/v1/backend/SPRING_LV_3_\352\271\200\354\230\201\355\225\234_\354\235\264\353\217\231\354\247\204_\352\267\270\353\246\254\352\263\240/src/main/resources/application.yml"
@@ -1,10 +1,20 @@
 spring:
   datasource:
     driver-class-name: org.mariadb.jdbc.Driver
-    url: jdbc:mariadb://localhost:3306/test?serverTimezone=Asia/Seoul&characterEncoding=UTF-8
+    url: jdbc:mariadb://localhost:3306/test?allowPublicKeyRetrieval=true&useSSL=false
     username: root
-    password: example
+    password: Abcd123@
+  #  datasource:
+  #    driver-class-name: org.h2.Driver
+  #    url: jdbc:h2:mem:;MODE=MySQL
+  #    username: root
+  #    password: test_password
 
   jpa:
     hibernate:
-      ddl-auto: create
\ No newline at end of file
+      ddl-auto: create
+    database-platform: org.hibernate.dialect.MariaDBDialect
+
+logging:
+  level:
+    org.springframework.jdbc.datasource: DEBUG
\ No newline at end of file