[3주차] 예약 API 구현 및 분산락 적용

movie-application/build.gradle

@@ -6,4 +6,7 @@ dependencies {
 	implementation("org.springframework.boot:spring-boot-starter-web")
 	implementation ("org.springframework.boot:spring-boot-starter-data-jpa")
 	implementation("org.springframework.boot:spring-boot-starter-validation")
+
+	// Redis AOP 기반 분산 락 구현시 애노테이션 사용을 위해 추가
+	implementation 'org.redisson:redisson-spring-boot-starter:3.22.0'
 }

movie-application/src/main/java/com/example/application/dto/request/MovieSearchCriteria.java

@@ -0,0 +1,9 @@
+package com.example.application.dto.request;
+
+import com.example.domain.model.valueObject.Genre;
+
+public record MovieSearchCriteria(
+        String title,
+        Genre genre
+) {
+}

movie-application/src/main/java/com/example/application/dto/request/ReservationRequestDto.java

@@ -0,0 +1,9 @@
+package com.example.application.dto.request;
+
+import java.util.List;
+
+public record ReservationRequestDto(
+        Long screeningId,
+        Long memberId,
+        List<Long> seatIds
+) {}

movie-application/src/main/java/com/example/application/dto/response/ReservationResponseDto.java

@@ -0,0 +1,26 @@
+package com.example.application.dto.response;
+
+import com.example.domain.model.entity.Reservation;
+import java.time.LocalTime;
+import java.util.List;
+
+public record ReservationResponseDto(
+        String memberName,
+        String movieTitle,
+        String theaterName,
+        LocalTime screeningStartTime,
+        List<String> reservedSeats
+) {
+    public static ReservationResponseDto fromEntity(Reservation reservation) {
+        return new ReservationResponseDto(
+                reservation.getMember().getName(),
+                reservation.getScreening().getMovie().getTitle(),
+                reservation.getScreening().getTheater().getName(),
+                reservation.getScreening().getStartTime(),
+                reservation.getReservedSeats().stream()
+                        .map(rs -> rs.getScreeningSeat().getSeat().getSeatNumber().toString())
+                        .toList()
+        );
+    }
+}
+

movie-application/src/main/java/com/example/application/exception/GlobalExceptionHandler.java

@@ -12,7 +12,7 @@ public class GlobalExceptionHandler {
     public ResponseEntity<ErrorResponse> handleCustomException(CustomException ex) {
         ErrorResponse errorResponse = new ErrorResponse(
                 ex.getErrorCode().name(),
-                ex.getErrorCode().getMessage(),
+                ex.getCustomMessage(),
                 ex.getErrorCode().getStatusCode()
         );
         return ResponseEntity.status(ex.getErrorCode().getStatusCode()).body(errorResponse);

movie-application/src/main/java/com/example/application/lock/DistributedLock.java

@@ -0,0 +1,15 @@
+package com.example.application.lock;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target(ElementType.METHOD)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface DistributedLock {
+    String key();
+    long waitTime() default 2_000;   // 적당한 대기 시간을 고려해 잠금 시간의 2배 정도로 설정
+    long leaseTime() default 1_000; // 지연을 고려해 트랜잭션 평균 실행 시간의 2배 정도로 설정
+}
+

movie-application/src/main/java/com/example/application/lock/DistributedLockAspect.java

@@ -0,0 +1,47 @@
+package com.example.application.lock;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.aspectj.lang.ProceedingJoinPoint;
+import org.aspectj.lang.annotation.Around;
+import org.aspectj.lang.annotation.Aspect;
+import org.redisson.api.RLock;
+import org.redisson.api.RedissonClient;
+import org.springframework.stereotype.Component;
+
+import java.util.concurrent.TimeUnit;
+
+@Slf4j
+@Aspect
+@Component
+@RequiredArgsConstructor
+public class DistributedLockAspect {
+
+    private final RedissonClient redissonClient;
+
+    @Around("@annotation(distributedLock)")
+    public Object applyLock(ProceedingJoinPoint joinPoint, DistributedLock distributedLock) throws Throwable {
+        String lockKey = distributedLock.key();
+        long waitTime = distributedLock.waitTime();
+        long leaseTime = distributedLock.leaseTime();
+
+        RLock lock = redissonClient.getLock(lockKey);
+
+        boolean acquired = lock.tryLock(waitTime, leaseTime, TimeUnit.MILLISECONDS);
+        if (!acquired) {
+            log.warn("[Distributed Lock] 락 획득 실패: {}", lockKey);
+            throw new RuntimeException("Seat is already reserved by another transaction.");
+        }
+
+        try {
+            log.info("[Distributed Lock] 락 획득 성공: {}", lockKey);
+            return joinPoint.proceed();
+        } finally {
+            if (lock.isHeldByCurrentThread()) {
+                lock.unlock();
+                log.info("[Distributed Lock] 락 해제 완료: {}", lockKey);
+            }
+        }
+    }
+
+}

movie-application/src/main/java/com/example/application/lock/DistributedLockExecutor.java

@@ -0,0 +1,7 @@
+package com.example.application.lock;
+
+import java.util.function.Supplier;
+
+public interface DistributedLockExecutor {
+    <T> T executeWithLock(String key, long waitTime, long leaseTime, Supplier<T> task);
+}

movie-application/src/main/java/com/example/application/lock/RedissonDistributedLockExecutor.java

@@ -0,0 +1,39 @@
+package com.example.application.lock;
+
+import java.util.concurrent.TimeUnit;
+import java.util.function.Supplier;
+import org.redisson.api.RLock;
+import org.redisson.api.RedissonClient;
+import org.springframework.stereotype.Component;
+
+@Component
+public class RedissonDistributedLockExecutor implements DistributedLockExecutor {
+
+    private final RedissonClient redissonClient;
+
+    public RedissonDistributedLockExecutor(RedissonClient redissonClient) {
+        this.redissonClient = redissonClient;
+    }
+
+    @Override
+    public <T> T executeWithLock(String key, long waitTime, long leaseTime, Supplier<T> task) {
+        RLock lock = redissonClient.getLock(key);
+        boolean acquired = false;
+
+        try {
+            acquired = lock.tryLock(waitTime, leaseTime, TimeUnit.MILLISECONDS);
+            if (!acquired) {
+                throw new IllegalStateException("[ERROR] Unable to acquire lock for key: " + key);
+            }
+            return task.get();
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            throw new RuntimeException("[ERROR] Lock acquisition interrupted", e);
+        } finally {
+            if (acquired) {
+                lock.unlock();
+            }
+        }
+    }
+
+}

movie-application/src/main/java/com/example/application/port/in/MessageServicePort.java

@@ -0,0 +1,5 @@
+package com.example.application.port.in;
+
+public interface MessageServicePort {
+    void send(String message);
+}

movie-application/src/main/java/com/example/application/port/in/MovieServicePort.java

@@ -1,13 +1,13 @@
 package com.example.application.port.in;
 
 import com.example.application.dto.request.MovieRequestDto;
+import com.example.application.dto.request.MovieSearchCriteria;
 import com.example.application.dto.request.ScreeningRequestDto;
 import com.example.application.dto.response.MovieResponseDto;
-import com.example.domain.model.valueObject.Genre;
 import java.util.List;
 
 public interface MovieServicePort {
-    List<MovieResponseDto> findMovies(String title, Genre genre);
+    List<MovieResponseDto> findMovies(MovieSearchCriteria movieSearchCriteria);
     void createMovie(MovieRequestDto movieRequestDto);
     void addScreeningToMovie(Long movieId, ScreeningRequestDto screeningRequestDto);
 }

movie-application/src/main/java/com/example/application/port/in/ReservationServicePort.java

@@ -0,0 +1,8 @@
+package com.example.application.port.in;
+
+import com.example.application.dto.request.ReservationRequestDto;
+import com.example.application.dto.response.ReservationResponseDto;
+
+public interface ReservationServicePort {
+    ReservationResponseDto create(ReservationRequestDto reservationRequestDto);
+}

movie-application/src/main/java/com/example/application/port/out/MemberRepositoryPort.java

@@ -0,0 +1,8 @@
+package com.example.application.port.out;
+
+import com.example.domain.model.entity.Member;
+import java.util.Optional;
+
+public interface MemberRepositoryPort {
+    Optional<Member> findById(Long id);
+}

movie-application/src/main/java/com/example/application/port/out/MovieRepositoryPort.java

@@ -1,19 +1,13 @@
 package com.example.application.port.out;
 
+import com.example.application.dto.request.MovieSearchCriteria;
 import com.example.domain.model.entity.Movie;
-import com.example.domain.model.valueObject.Genre;
 import java.util.List;
 import java.util.Optional;
 import org.springframework.data.domain.Sort;
 
-/**
- * Represents a port for accessing movie data from a persistence layer.
- * This interface provides an abstraction that allows the application layer
- * to interact with various repository implementations
- * (e.g., databases, external APIs).
- */
 public interface MovieRepositoryPort {
-    List<Movie> findBy(String title, Genre genre, Sort sort);
+    List<Movie> findBy(MovieSearchCriteria movieSearchCriteria, Sort sort);
     void save(Movie movie);
     Optional<Movie> findById(Long id);
 }

movie-application/src/main/java/com/example/application/port/out/ReservationRepositoryPort.java

@@ -0,0 +1,13 @@
+package com.example.application.port.out;
+
+import com.example.domain.model.entity.Member;
+import com.example.domain.model.entity.Reservation;
+import com.example.domain.model.entity.Screening;
+import java.util.Optional;
+
+public interface ReservationRepositoryPort {
+    void save(Reservation reservation);
+    Optional<Reservation> findById(Long id);
+    void deleteAll();
+    int countByScreeningAndMember(Screening screening, Member member);
+}

movie-application/src/main/java/com/example/application/port/out/ReservationValidationPort.java

@@ -0,0 +1,11 @@
+package com.example.application.port.out;
+
+import com.example.domain.model.entity.ScreeningSeat;
+import com.example.domain.model.entity.Seat;
+import java.util.List;
+
+public interface ReservationValidationPort {
+    void validateMaxSeatsPerScreening(int existingReservations, int newSeatCount);
+    void validateSeatsAreConsecutive(List<Seat> seats);
+    void validateSeatsExist(List<Long> requestedSeatIds, List<ScreeningSeat> foundSeats);
+}

movie-application/src/main/java/com/example/application/port/out/ReservedSeatRepositoryPort.java

@@ -0,0 +1,8 @@
+package com.example.application.port.out;
+
+import com.example.domain.model.entity.ReservedSeat;
+import java.util.List;
+
+public interface ReservedSeatRepositoryPort {
+    void saveAll(List<ReservedSeat> reservedSeats);
+}

movie-application/src/main/java/com/example/application/port/out/ScreeningRepositoryPort.java

@@ -1,13 +1,11 @@
 package com.example.application.port.out;
 
 import com.example.domain.model.entity.Screening;
+import java.util.List;
+import java.util.Optional;
 
-/**
- * Represents a port for accessing movie data from a persistence layer.
- * This interface provides an abstraction that allows the application layer
- * to interact with various repository implementations
- * (e.g., databases, external APIs).
- */
 public interface ScreeningRepositoryPort {
     void save(Screening screening);
+    Optional<Screening> findById(Long id);
+    List<Screening> findAll();
 }

movie-application/src/main/java/com/example/application/port/out/ScreeningSeatRepositoryPort.java

@@ -0,0 +1,13 @@
+package com.example.application.port.out;
+
+import com.example.domain.model.entity.Screening;
+import com.example.domain.model.entity.ScreeningSeat;
+import java.util.List;
+
+public interface ScreeningSeatRepositoryPort {
+    List<ScreeningSeat> findByScreeningAndSeatIds(Screening screening, List<Long> seatIds);
+    void save(ScreeningSeat screeningSeat);
+    long count();
+    void resetAllReservations();
+    long countReservedSeats(Long screeningId);
+}

movie-application/src/main/java/com/example/application/port/out/SeatRepositoryPort.java

@@ -0,0 +1,8 @@
+package com.example.application.port.out;
+
+import com.example.domain.model.entity.Seat;
+import java.util.List;
+
+public interface SeatRepositoryPort {
+    List<Seat> findAll();
+}

movie-application/src/main/java/com/example/application/port/out/TheaterRepositoryPort.java

@@ -3,12 +3,6 @@
 import com.example.domain.model.entity.Theater;
 import java.util.Optional;
 
-/**
- * Represents a port for accessing movie data from a persistence layer.
- * This interface provides an abstraction that allows the application layer
- * to interact with various repository implementations
- * (e.g., databases, external APIs).
- */
 public interface TheaterRepositoryPort {
     Optional<Theater> findById(Long id);
 }

movie-application/src/main/java/com/example/application/service/MessageService.java

@@ -0,0 +1,23 @@
+package com.example.application.service;
+
+import com.example.application.port.in.MessageServicePort;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Service;
+
+@Slf4j
+@Service
+public class MessageService implements MessageServicePort {
+
+    @Override
+    public void send(String message) {
+        try {
+            log.info("[MessageService] 전송 시작: {}", message);
+            Thread.sleep(500); // 메시지 전송에 걸리는 시간 가정
+            log.info("[MessageService] 전송 완료: {}", message);
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt(); // 현재 스레드가 인터럽트 상태임을 유지하도록 설정
+            log.error("[MessageService] 전송 실패!", e);
+        }
+    }
+
+}

movie-application/src/main/java/com/example/application/service/MovieService.java

@@ -1,6 +1,7 @@
 package com.example.application.service;
 
 import com.example.application.dto.request.MovieRequestDto;
+import com.example.application.dto.request.MovieSearchCriteria;
 import com.example.application.dto.request.ScreeningRequestDto;
 import com.example.application.dto.response.MovieResponseDto;
 import com.example.application.port.in.MovieServicePort;
@@ -12,7 +13,6 @@
 import com.example.domain.model.entity.Movie;
 import com.example.domain.model.entity.Screening;
 import com.example.domain.model.entity.Theater;
-import com.example.domain.model.valueObject.Genre;
 import java.util.List;
 import lombok.RequiredArgsConstructor;
 import org.springframework.cache.annotation.Cacheable;
@@ -27,12 +27,13 @@ public class MovieService implements MovieServicePort {
     private final ScreeningRepositoryPort screeningRepositoryPort;
     private final TheaterRepositoryPort theaterRepositoryPort;
 
-    @Cacheable(value = "movies", key = "#title + '-' + #genre")
+    @Cacheable(value = "movies", key = "#movieSearchCriteria.title + '-' + #movieSearchCriteria.genre")
     @Override
-    public List<MovieResponseDto> findMovies(String title, Genre genre) {
+    public List<MovieResponseDto> findMovies(MovieSearchCriteria movieSearchCriteria) {
         Sort sort = Sort.by("releaseDate").descending();
 
-        return movieRepositoryPort.findBy(title, genre, sort).stream()
+        return movieRepositoryPort.findBy(movieSearchCriteria, sort
+                ).stream()
                 .map(MovieResponseDto::fromEntity)
                 .toList();
     }