Setting: 배포 환경을 세팅한다.

src/main/java/com/thirdparty/ticketing/domain/common/ErrorCode.java

@@ -42,6 +42,13 @@ public enum ErrorCode {
     */
     NOT_FOUND_SEAT_GRADE(HttpStatus.NOT_FOUND, "SG404-1", "존재하지 않는 구역입니다."),
 
+    /*
+       Seat Error
+    */
+    NOT_FOUND_SEAT(HttpStatus.NOT_FOUND, "S404-1", "존재하지 않는 좌석입니다."),
+    NOT_SELECTABLE_SEAT(HttpStatus.FORBIDDEN, "S403-1", "이미 선택된 좌석입니다."),
+    INVALID_SEAT_STATUS(HttpStatus.FORBIDDEN, "S403-2", "요청을 수행할 수 없는 좌석의 상태입니다."),
+
     /*
        Payment Error
     */

src/main/java/com/thirdparty/ticketing/domain/common/LettuceRepository.java

@@ -0,0 +1,24 @@
+package com.thirdparty.ticketing.domain.common;
+
+import java.time.Duration;
+
+import org.springframework.data.redis.core.StringRedisTemplate;
+import org.springframework.stereotype.Repository;
+
+import lombok.RequiredArgsConstructor;
+
+@Repository
+@RequiredArgsConstructor
+public class LettuceRepository {
+    private final StringRedisTemplate redisTemplate;
+
+    // 1. lock을 생성
+    // 2. 60초가 유지되는 key는 자리번호 value는 유저 id를 생성
+    public Boolean seatLock(String key) {
+        return redisTemplate.opsForValue().setIfAbsent(key, "lock", Duration.ofMinutes(1));
+    }
+
+    public void unlock(String string) {
+        redisTemplate.delete(string);
+    }
+}

src/main/java/com/thirdparty/ticketing/domain/member/Member.java

@@ -1,6 +1,7 @@
 package com.thirdparty.ticketing.domain.member;
 
 import java.time.ZonedDateTime;
+import java.util.Objects;
 
 import jakarta.persistence.Column;
 import jakarta.persistence.Entity;
@@ -53,4 +54,17 @@ public Member(String email, String password, MemberRole memberRole, ZonedDateTim
         this.password = password;
         this.memberRole = memberRole;
     }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Member member = (Member) o;
+        return Objects.equals(memberId, member.memberId);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hashCode(memberId);
+    }
 }

src/main/java/com/thirdparty/ticketing/domain/seat/Seat.java

@@ -3,6 +3,8 @@
 import jakarta.persistence.*;
 
 import com.thirdparty.ticketing.domain.BaseEntity;
+import com.thirdparty.ticketing.domain.common.ErrorCode;
+import com.thirdparty.ticketing.domain.common.TicketingException;
 import com.thirdparty.ticketing.domain.member.Member;
 import com.thirdparty.ticketing.domain.zone.Zone;
 
@@ -43,6 +45,8 @@ public class Seat extends BaseEntity {
     @Column(length = 16, nullable = false)
     private SeatStatus seatStatus = SeatStatus.SELECTABLE;
 
+    @Version private Long version;
+
     public Seat(String seatCode, SeatStatus seatStatus) {
         this.seatCode = seatCode;
         this.seatStatus = seatStatus;
@@ -51,4 +55,30 @@ public Seat(String seatCode, SeatStatus seatStatus) {
     public boolean isSelectable() {
         return seatStatus.isSelectable();
     }
+
+    public void assignByMember(Member member) {
+        if (!isSelectable()) {
+            throw new TicketingException(ErrorCode.NOT_SELECTABLE_SEAT);
+        }
+        this.member = member;
+        this.seatStatus = SeatStatus.SELECTED;
+    }
+
+    public void markAsPendingPayment() {
+        if (!seatStatus.isSelected()) {
+            throw new TicketingException(ErrorCode.INVALID_SEAT_STATUS);
+        }
+        this.seatStatus = SeatStatus.PENDING_PAYMENT;
+    }
+
+    public void markAsPaid() {
+        if (!seatStatus.isPendingPayment()) {
+            throw new TicketingException(ErrorCode.INVALID_SEAT_STATUS);
+        }
+        this.seatStatus = SeatStatus.PAID;
+    }
+
+    public boolean isAssignedByMember(Member loginMember) {
+        return loginMember.equals(member);
+    }
 }

src/main/java/com/thirdparty/ticketing/domain/seat/SeatStatus.java

@@ -9,4 +9,16 @@ public enum SeatStatus {
     public boolean isSelectable() {
         return this == SELECTABLE;
     }
+
+    public boolean isSelected() {
+        return this == SELECTED;
+    }
+
+    public boolean isPendingPayment() {
+        return this == PENDING_PAYMENT;
+    }
+
+    public boolean isPaid() {
+        return this == PAID;
+    }
 }

src/main/java/com/thirdparty/ticketing/domain/seat/repository/SeatRepository.java

@@ -1,8 +1,13 @@
 package com.thirdparty.ticketing.domain.seat.repository;
 
 import java.util.List;
+import java.util.Optional;
+
+import jakarta.persistence.LockModeType;
 
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Lock;
+import org.springframework.data.jpa.repository.Query;
 import org.springframework.stereotype.Repository;
 
 import com.thirdparty.ticketing.domain.seat.Seat;
@@ -11,4 +16,12 @@
 @Repository
 public interface SeatRepository extends JpaRepository<Seat, Long> {
     List<Seat> findByZone(Zone zone);
+
+    @Query("SELECT s FROM Seat as s WHERE s.id = :seatId")
+    @Lock(LockModeType.OPTIMISTIC)
+    Optional<Seat> findByIdWithOptimistic(Long seatId);
+
+    @Query("SELECT s FROM Seat as s WHERE s.id = :seatId")
+    @Lock(LockModeType.PESSIMISTIC_WRITE)
+    Optional<Seat> findByIdWithPessimistic(Long seatId);
 }

src/main/java/com/thirdparty/ticketing/domain/ticket/controller/TicketController.java

@@ -2,6 +2,7 @@
 
 import jakarta.validation.Valid;
 
+import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PostMapping;
@@ -15,13 +16,15 @@
 import com.thirdparty.ticketing.domain.ticket.dto.TicketPaymentRequest;
 import com.thirdparty.ticketing.domain.ticket.service.TicketService;
 
-import lombok.RequiredArgsConstructor;
-
 @RestController("/api")
-@RequiredArgsConstructor
 public class TicketController {
+
     private final TicketService ticketService;
 
+    public TicketController(@Qualifier("lettuceCacheTicketService") TicketService ticketService) {
+        this.ticketService = ticketService;
+    }
+
     @GetMapping("/members/tickets")
     public ResponseEntity<ItemResult<TicketElement>> selectMyTickets(
             @LoginMember String memberEmail) {
@@ -31,15 +34,17 @@ public ResponseEntity<ItemResult<TicketElement>> selectMyTickets(
 
     @PostMapping("/seats/select")
     public ResponseEntity<Void> selectSeat(
+            @LoginMember String memberEmail,
             @RequestBody @Valid SeatSelectionRequest seatSelectionRequest) {
-        ticketService.selectSeat(seatSelectionRequest);
+        ticketService.selectSeat(memberEmail, seatSelectionRequest);
         return ResponseEntity.ok().build();
     }
 
     @PostMapping("/tickets")
     public ResponseEntity<Void> payTicket(
+            @LoginMember String memberEmail,
             @RequestBody @Valid TicketPaymentRequest ticketPaymentRequest) {
-        ticketService.reservationTicket(ticketPaymentRequest);
+        ticketService.reservationTicket(memberEmail, ticketPaymentRequest);
         return ResponseEntity.ok().build();
     }
 }

src/main/java/com/thirdparty/ticketing/domain/ticket/dto/SeatSelectionRequest.java

@@ -9,5 +9,5 @@
 public class SeatSelectionRequest {
     @NotNull(message = "좌석 ID를 요청하지 않았습니다.")
     @Min(value = 1, message = "좌석 ID는 1 이상이어야 합니다.")
-    private Long seatId;
+    private final Long seatId;
 }

src/main/java/com/thirdparty/ticketing/domain/ticket/dto/TicketPaymentRequest.java

@@ -9,5 +9,5 @@
 public class TicketPaymentRequest {
     @NotNull(message = "좌석 ID를 요청하지 않았습니다.")
     @Min(value = 1, message = "좌석 ID는 1 이상이어야 합니다.")
-    private Long seatId;
+    private final Long seatId;
 }

src/main/java/com/thirdparty/ticketing/domain/ticket/policy/LockSeatStrategy.java

@@ -0,0 +1,9 @@
+package com.thirdparty.ticketing.domain.ticket.policy;
+
+import java.util.Optional;
+
+import com.thirdparty.ticketing.domain.seat.Seat;
+
+public interface LockSeatStrategy {
+    Optional<Seat> getSeatWithLock(Long seatId);
+}

src/main/java/com/thirdparty/ticketing/domain/ticket/policy/OptimisticLockSeatStrategy.java

@@ -0,0 +1,23 @@
+package com.thirdparty.ticketing.domain.ticket.policy;
+
+import java.util.Optional;
+
+import org.springframework.context.annotation.Primary;
+import org.springframework.stereotype.Component;
+
+import com.thirdparty.ticketing.domain.seat.Seat;
+import com.thirdparty.ticketing.domain.seat.repository.SeatRepository;
+
+import lombok.RequiredArgsConstructor;
+
+@Primary
+@Component
+@RequiredArgsConstructor
+public class OptimisticLockSeatStrategy implements LockSeatStrategy {
+    private final SeatRepository seatRepository;
+
+    @Override
+    public Optional<Seat> getSeatWithLock(Long seatId) {
+        return seatRepository.findByIdWithOptimistic(seatId);
+    }
+}

src/main/java/com/thirdparty/ticketing/domain/ticket/policy/PessimisticLockSeatStrategy.java

@@ -0,0 +1,21 @@
+package com.thirdparty.ticketing.domain.ticket.policy;
+
+import java.util.Optional;
+
+import org.springframework.stereotype.Component;
+
+import com.thirdparty.ticketing.domain.seat.Seat;
+import com.thirdparty.ticketing.domain.seat.repository.SeatRepository;
+
+import lombok.RequiredArgsConstructor;
+
+@Component
+@RequiredArgsConstructor
+public class PessimisticLockSeatStrategy implements LockSeatStrategy {
+    private final SeatRepository seatRepository;
+
+    @Override
+    public Optional<Seat> getSeatWithLock(Long seatId) {
+        return seatRepository.findByIdWithPessimistic(seatId);
+    }
+}

src/main/java/com/thirdparty/ticketing/domain/ticket/service/CacheTicketService.java

@@ -17,8 +17,8 @@ public CacheTicketService(
     }
 
     @Override
-    public void selectSeat(SeatSelectionRequest seatSelectionRequest) {}
+    public void selectSeat(String memberEmail, SeatSelectionRequest seatSelectionRequest) {}
 
     @Override
-    public void reservationTicket(TicketPaymentRequest ticketPaymentRequest) {}
+    public void reservationTicket(String memberEmail, TicketPaymentRequest ticketPaymentRequest) {}
 }

src/main/java/com/thirdparty/ticketing/domain/ticket/service/LettuceCacheTicketService.java

@@ -0,0 +1,69 @@
+package com.thirdparty.ticketing.domain.ticket.service;
+
+import org.springframework.stereotype.Service;
+
+import com.thirdparty.ticketing.domain.common.LettuceRepository;
+import com.thirdparty.ticketing.domain.member.repository.MemberRepository;
+import com.thirdparty.ticketing.domain.payment.PaymentProcessor;
+import com.thirdparty.ticketing.domain.seat.repository.SeatRepository;
+import com.thirdparty.ticketing.domain.ticket.dto.SeatSelectionRequest;
+import com.thirdparty.ticketing.domain.ticket.dto.TicketPaymentRequest;
+import com.thirdparty.ticketing.domain.ticket.repository.TicketRepository;
+
+@Service
+public class LettuceCacheTicketService extends TicketService {
+    private final CacheTicketService cacheTicketService;
+    private final LettuceRepository lettuceRepository;
+
+    public LettuceCacheTicketService(
+            MemberRepository memberRepository,
+            TicketRepository ticketRepository,
+            SeatRepository seatRepository,
+            PaymentProcessor paymentProcessor,
+            CacheTicketService cacheTicketService,
+            LettuceRepository lettuceRepository) {
+        super(memberRepository, ticketRepository, seatRepository, paymentProcessor);
+        this.cacheTicketService = cacheTicketService;
+        this.lettuceRepository = lettuceRepository;
+    }
+
+    @Override
+    public void selectSeat(String memberEmail, SeatSelectionRequest seatSelectionRequest) {
+        int limit = 5;
+        try {
+            while (limit > 0
+                    && !lettuceRepository.seatLock(seatSelectionRequest.getSeatId().toString())) {
+                limit -= 1;
+                Thread.sleep(300);
+            }
+
+            if (limit > 0) {
+                cacheTicketService.selectSeat(memberEmail, seatSelectionRequest);
+            }
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        } finally {
+            lettuceRepository.unlock(seatSelectionRequest.getSeatId().toString());
+        }
+    }
+
+    @Override
+    public void reservationTicket(String memberEmail, TicketPaymentRequest ticketPaymentRequest) {
+        int limit = 5;
+        try {
+            while (limit > 0
+                    && !lettuceRepository.seatLock(ticketPaymentRequest.getSeatId().toString())) {
+                limit -= 1;
+                Thread.sleep(300);
+            }
+
+            if (limit > 0) {
+                cacheTicketService.reservationTicket(memberEmail, ticketPaymentRequest);
+            }
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        } finally {
+            lettuceRepository.unlock(ticketPaymentRequest.getSeatId().toString());
+        }
+    }
+}