[feat] 지원서 엑셀 파일 생성 시각 API 구현 (#107)

* [chore] 지원서 엑셀 파일 생성 시각 API

* [test] 지원서 엑셀 파일 생성 시각 API (#105)

src/main/java/ceos/backend/domain/application/ApplicationController.java

@@ -165,4 +165,11 @@ public ResponseEntity<FileSystemResource> getApplicationExcel() {
                                 "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"))
                 .body(resource);
     }
+
+    @Operation(summary = "지원서 엑셀 파일 생성 시각 확인")
+    @GetMapping(value = "/file/creationtime")
+    public GetCreationTime getApplicationExcelCreationTime() {
+        log.info("지원서 엑셀 파일 생성 시각 확인");
+        return applicationExcelService.getApplicationExcelCreationTime();
+    }
 }

src/main/java/ceos/backend/domain/application/service/ApplicationExcelService.java

@@ -171,4 +171,13 @@ public void createApplicationExcelFile() throws IOException {
         // 워크북 및 자원 해제
         workbook.close();
     }
+
+    @Transactional(readOnly = true)
+    public GetCreationTime getApplicationExcelCreationTime() {
+        Recruitment recruitment = recruitmentRepository.findAll().get(0);
+        LocalDateTime applicationExcelCreatedAt = recruitment.getApplicationExcelCreatedAt();
+
+        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm");
+        return GetCreationTime.from(applicationExcelCreatedAt.format(formatter));
+    }
 }

src/test/java/ceos/backend/domain/application/ApplicationControllerTest.java

@@ -0,0 +1,25 @@
+package ceos.backend.domain.application;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
+import org.springframework.test.web.servlet.result.MockMvcResultMatchers;
+
+@SpringBootTest
+@AutoConfigureMockMvc
+public class ApplicationControllerTest {
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    @DisplayName("지원서 엑셀 파일 생성 시각 API - 권한 X")
+    @Test
+    void getApplicationExcelCreationTime() throws Exception {
+        mockMvc.perform(MockMvcRequestBuilders.get("/applications/file/creationtime"))
+                .andExpect(MockMvcResultMatchers.status().is(401));
+    }
+}

src/test/java/ceos/backend/domain/application/ApplicationExcelServiceTest.java

@@ -0,0 +1,24 @@
+package ceos.backend.domain.application;
+
+import ceos.backend.domain.application.dto.response.GetCreationTime;
+import ceos.backend.domain.application.service.ApplicationExcelService;
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+public class ApplicationExcelServiceTest {
+
+    @Autowired
+    ApplicationExcelService applicationExcelService;
+
+    @DisplayName("지원서 엑셀 파일 생성 시각")
+    @Test
+    public void getApplicationExcelCreationTime() throws Exception {
+        GetCreationTime creationTime = applicationExcelService.getApplicationExcelCreationTime();
+        Assertions.assertThat(creationTime.getCreateAt().charAt(4)).isEqualTo('-');
+        Assertions.assertThat(creationTime.getCreateAt().charAt(7)).isEqualTo('-');
+    }
+}