feat(#85): 학생회비 납부자 엑셀 다운로드 구현

Author: tnals0924

src/main/kotlin/site/billilge/api/backend/domain/payer/controller/AdminPayerController.kt

@@ -1,15 +1,19 @@
 package site.billilge.api.backend.domain.payer.controller
 
+import org.springframework.core.io.InputStreamResource
+import org.springframework.http.ContentDisposition
+import org.springframework.http.HttpHeaders
 import org.springframework.http.ResponseEntity
 import org.springframework.web.bind.annotation.*
 import site.billilge.api.backend.domain.payer.dto.request.PayerDeleteRequest
 import site.billilge.api.backend.domain.payer.dto.request.PayerRequest
-import site.billilge.api.backend.domain.payer.dto.response.PayerExcelFileResponse
 import site.billilge.api.backend.domain.payer.dto.response.PayerFindAllResponse
 import site.billilge.api.backend.domain.payer.service.PayerService
 import site.billilge.api.backend.global.annotation.OnlyAdmin
 import site.billilge.api.backend.global.dto.PageableCondition
 import site.billilge.api.backend.global.dto.SearchCondition
+import java.time.LocalDate
+import java.time.format.DateTimeFormatter
 
 @RestController
 @RequestMapping("/admin/members/payers")
@@ -38,7 +42,18 @@ class AdminPayerController(
     }
 
     @GetMapping("/excel")
-    fun getExcelFileUrl(): ResponseEntity<PayerExcelFileResponse> {
-        return ResponseEntity.ok(payerService.getExcelFileUrl());
+    fun createPayerExcel(): ResponseEntity<InputStreamResource> {
+        val excel = payerService.createPayerExcel()
+        val currentDate = LocalDate.now()
+        val dateFormatter = DateTimeFormatter.ofPattern("yyyyMMdd")
+        val headers = HttpHeaders().apply {
+            contentDisposition = ContentDisposition.builder("attachment")
+                .filename("kmusw_payers_${dateFormatter.format(currentDate)}.xlsx")
+                .build()
+        }
+
+        return ResponseEntity.ok()
+            .headers(headers)
+            .body(InputStreamResource((excel)))
     }
 }

src/main/kotlin/site/billilge/api/backend/domain/payer/dto/response/PayerExcelFileResponse.kt

@@ -15,4 +15,6 @@ interface PayerRepository : JpaRepository<Payer, Long?> {
 
     @Query("SELECT p FROM Payer p WHERE p.name LIKE CONCAT('%', :name, '%')")
     fun findAllByNameContaining(@Param("name") name: String, pageable: Pageable): Page<Payer>
+
+    fun findAllByEnrollmentYear(enrollmentYear: String): List<Payer>
 }

src/main/kotlin/site/billilge/api/backend/domain/payer/event/PayerEvents.kt

@@ -1,7 +1,5 @@
 package site.billilge.api.backend.domain.payer.service
 
-import org.springframework.beans.factory.annotation.Value
-import org.springframework.context.ApplicationEventPublisher
 import org.springframework.data.domain.PageRequest
 import org.springframework.data.domain.Sort
 import org.springframework.stereotype.Service
@@ -10,25 +8,25 @@ import site.billilge.api.backend.domain.member.entity.Member
 import site.billilge.api.backend.domain.member.repository.MemberRepository
 import site.billilge.api.backend.domain.payer.dto.request.PayerDeleteRequest
 import site.billilge.api.backend.domain.payer.dto.request.PayerRequest
-import site.billilge.api.backend.domain.payer.dto.response.PayerExcelFileResponse
 import site.billilge.api.backend.domain.payer.dto.response.PayerFindAllResponse
 import site.billilge.api.backend.domain.payer.dto.response.PayerSummary
 import site.billilge.api.backend.domain.payer.entity.Payer
-import site.billilge.api.backend.domain.payer.event.PayerAddEvent
-import site.billilge.api.backend.domain.payer.event.PayerDeleteEvent
 import site.billilge.api.backend.domain.payer.repository.PayerRepository
 import site.billilge.api.backend.global.dto.PageableCondition
 import site.billilge.api.backend.global.dto.SearchCondition
-import java.time.LocalDate
+import site.billilge.api.backend.global.utils.ExcelGenerator
+import site.billilge.api.backend.global.utils.ExcelRow
+import java.io.ByteArrayInputStream
+import java.time.Year
 
 @Service
 @Transactional(readOnly = true)
 class PayerService(
-    private val publisher: ApplicationEventPublisher,
     private val payerRepository: PayerRepository,
+
     private val memberRepository: MemberRepository,
-    @Value("\${cloud.aws.s3.base-url}")
-    private val s3BaseUrl: String,
+
+    private val excelGenerator: ExcelGenerator
 ) {
     fun isPayer(name: String, studentId: String): Boolean {
         val enrollmentYear = studentId.substring(0, 4)
@@ -104,28 +102,35 @@ class PayerService(
         }
 
         payerRepository.saveAll(newPayers)
-
-        publisher.publishEvent(PayerAddEvent(newPayers.map { it.id }))
     }
 
     @Transactional
     fun deletePayers(request: PayerDeleteRequest) {
         val payerStudentIds = payerRepository.findAllByIds(request.payerIds)
             .mapNotNull { it.studentId }
-            .toList()
 
         memberRepository.findAllByStudentIds(payerStudentIds)
             .forEach { member ->
                 member.isFeePaid = false
             }
 
         payerRepository.deleteAllById(request.payerIds)
-
-        publisher.publishEvent(PayerDeleteEvent(request.payerIds))
     }
 
-    fun getExcelFileUrl(): PayerExcelFileResponse {
-        val currentYear = LocalDate.now().year
-        return PayerExcelFileResponse(s3BaseUrl + "/payers/payer_${currentYear}.xlsx")
+    fun createPayerExcel(): ByteArrayInputStream {
+        val startYear = 2015
+        val currentYear = Year.now().value
+        val headerTitles = arrayOf("이름", "학번")
+        val sheetData = mutableMapOf<String, Pair<Array<String>, List<ExcelRow>>>()
+
+        for (year in startYear..currentYear) {
+            val yearText = "$year"
+            val payersByYearExcelRow = payerRepository.findAllByEnrollmentYear(yearText)
+                .map { payer -> ExcelRow(payer.name, payer.studentId ?: "${yearText}XXXX") }
+
+            sheetData.put(yearText, headerTitles to payersByYearExcelRow)
+        }
+
+        return excelGenerator.generateByMultipleSheets(sheetData)
     }
 }