add :: 조기귀가신청 중복확인

src/main/kotlin/dsm/pick2024/domain/application/exception/AlreadyApplyingForEarlyReturnException.kt

@@ -0,0 +1,8 @@
+package dsm.pick2024.domain.application.exception
+
+import dsm.pick2024.global.error.exception.ErrorCode
+import dsm.pick2024.global.error.exception.PickException
+
+object AlreadyApplyingForEarlyReturnException : PickException(
+    ErrorCode.ALREADY_APPLYING_EARLY_RETURN
+)

src/main/kotlin/dsm/pick2024/domain/application/persistence/EarlyReturnPersistenceAdapter.kt

@@ -15,4 +15,7 @@ class EarlyReturnPersistenceAdapter(
     override fun save(earlyReturn: EarlyReturn) {
         earlyReturnRepository.save(earlyReturnMapper.toEntity(earlyReturn))
     }
+
+    override fun existsByUsername(username: String) =
+        earlyReturnRepository.existsByUsername(username)
 }

src/main/kotlin/dsm/pick2024/domain/application/persistence/repository/EarlyReturnRepository.kt

@@ -4,4 +4,6 @@ import dsm.pick2024.domain.application.entity.EarlyReturnJpaEntity
 import org.springframework.data.jpa.repository.JpaRepository
 import java.util.UUID
 
-interface EarlyReturnRepository : JpaRepository<EarlyReturnJpaEntity, UUID>
+interface EarlyReturnRepository : JpaRepository<EarlyReturnJpaEntity, UUID> {
+    fun existsByUsername(username: String): Boolean
+}

src/main/kotlin/dsm/pick2024/domain/application/port/out/EarlyReturnPort.kt

@@ -1,3 +1,5 @@
 package dsm.pick2024.domain.application.port.out
 
-interface EarlyReturnPort : SaveEarlyReturnPort
+interface EarlyReturnPort :
+    SaveEarlyReturnPort,
+    ExistsEarlyReturnByUsernamePort

src/main/kotlin/dsm/pick2024/domain/application/port/out/ExistsEarlyReturnByUsernamePort.kt

@@ -0,0 +1,5 @@
+package dsm.pick2024.domain.application.port.out
+
+interface ExistsEarlyReturnByUsernamePort {
+    fun existsByUsername(username: String): Boolean?
+}

src/main/kotlin/dsm/pick2024/domain/application/service/CreateEarlyReturnService.kt

@@ -2,7 +2,9 @@ package dsm.pick2024.domain.application.service
 
 import dsm.pick2024.domain.application.domain.EarlyReturn
 import dsm.pick2024.domain.application.enums.Status
+import dsm.pick2024.domain.application.exception.AlreadyApplyingForEarlyReturnException
 import dsm.pick2024.domain.application.port.`in`.CreateEarlyReturnUseCase
+import dsm.pick2024.domain.application.port.out.ExistsEarlyReturnByUsernamePort
 import dsm.pick2024.domain.application.port.out.SaveEarlyReturnPort
 import dsm.pick2024.domain.application.presentation.dto.request.CreateEarlyReturnRequest
 import dsm.pick2024.domain.user.port.`in`.UserFacadeUseCase
@@ -12,12 +14,18 @@ import org.springframework.transaction.annotation.Transactional
 @Service
 class CreateEarlyReturnService(
     private val saveEarlyReturnPort: SaveEarlyReturnPort,
+    private val existsEarlyReturnByUsernamePort: ExistsEarlyReturnByUsernamePort,
     private val userFacadeUseCase: UserFacadeUseCase
 ) : CreateEarlyReturnUseCase {
 
     @Transactional
     override fun createEarlyReturn(request: CreateEarlyReturnRequest) {
         val user = userFacadeUseCase.currentUser()
+
+        if (existsEarlyReturnByUsernamePort.existsByUsername(user.name) == true) {
+            throw AlreadyApplyingForEarlyReturnException
+        }
+
         saveEarlyReturnPort.save(
             EarlyReturn(
                 username = user.name,

src/main/kotlin/dsm/pick2024/global/error/exception/ErrorCode.kt

@@ -17,6 +17,8 @@ enum class ErrorCode(
     SELF_STUDY_NOT_FOUND(404, "Self Study Not Found"),
     EXISTS_SELF_STUDY_TEACHER(409, "Exists Self Study Teacher"),
 
+    ALREADY_APPLYING_EARLY_RETURN(409, "Already applying For Early Return Application"),
+
     ALREADY_APPLYING_MOVEMENT(409, "Already applying for movement"),
 
     INVALID_TOKEN(401, "Invalid Token"),