Feature/288 presigned 이미지 업로드 방식 구현

src/main/java/com/somemore/global/imageupload/service/ImageUploadService.java

@@ -5,16 +5,18 @@
 import com.somemore.global.imageupload.usecase.ImageUploadUseCase;
 import com.somemore.global.imageupload.util.ImageUploadUtils;
 import com.somemore.global.imageupload.validator.ImageUploadValidator;
-import jakarta.annotation.PostConstruct;
 import lombok.RequiredArgsConstructor;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Service;
 import org.springframework.web.multipart.MultipartFile;
 import software.amazon.awssdk.core.sync.RequestBody;
 import software.amazon.awssdk.services.s3.S3Client;
 import software.amazon.awssdk.services.s3.model.PutObjectRequest;
+import software.amazon.awssdk.services.s3.presigner.S3Presigner;
+import software.amazon.awssdk.services.s3.presigner.model.GetObjectPresignRequest;
 
 import java.io.IOException;
+import java.time.Duration;
 
 import static com.somemore.global.exception.ExceptionMessage.UPLOAD_FAILED;
 
@@ -23,6 +25,7 @@
 public class ImageUploadService implements ImageUploadUseCase {
 
     private final S3Client s3Client;
+    private final S3Presigner s3Presigner;
     private final ImageUploadValidator imageUploadValidator;
 
     @Value("${cloud.aws.s3.bucket}")
@@ -34,11 +37,28 @@ public class ImageUploadService implements ImageUploadUseCase {
     @Value("${default.image.url}")
     private String defaultImageUrl;
 
-    public static String DEFAULT_IMAGE_URL;
+    public static final String DEFAULT_IMAGE_URL = "";
+    private static final Duration GET_URL_EXPIRATION_DURATION = Duration.ofMinutes(3);
 
-    @PostConstruct
-    private void init() {
-        DEFAULT_IMAGE_URL = defaultImageUrl;
+
+    @Override
+    public String getPresignedUrl(String filename) {
+        if(imageUploadValidator.isEmptyFileName(filename)) {
+            return null;
+        }
+
+        String uniqueFilename = ImageUploadUtils.generateUniqueFileName(filename);
+
+        GetObjectPresignRequest getObjectPresignRequest = GetObjectPresignRequest.builder()
+                .signatureDuration(GET_URL_EXPIRATION_DURATION)
+                .getObjectRequest(builder -> builder
+                        .bucket(bucket)
+                        .key(uniqueFilename))
+                .build();
+
+        return s3Presigner.presignGetObject(getObjectPresignRequest)
+                .url()
+                .toString();
     }
 
     @Override

src/main/java/com/somemore/global/imageupload/usecase/ImageUploadUseCase.java

@@ -4,4 +4,5 @@
 
 public interface ImageUploadUseCase {
     String uploadImage(ImageUploadRequestDto requestDto);
+    String getPresignedUrl(String filename);
 }

src/main/java/com/somemore/global/imageupload/util/ImageUploadUtils.java

@@ -11,9 +11,14 @@ private ImageUploadUtils() {
     }
 
     public static String generateUniqueFileName(String originalFileName) {
+
         String uuid = UUID.randomUUID().toString();
+
         String fileExtension = extractFileExtension(originalFileName);
-        return uuid + fileExtension;
+
+        String fileNameWithoutExtension = originalFileName.substring(0, originalFileName.lastIndexOf("."));
+
+        return uuid + "_" + fileNameWithoutExtension + fileExtension;
     }
 
     private static String extractFileExtension(String fileName) {

src/main/java/com/somemore/global/imageupload/validator/DefaultImageUploadValidator.java

@@ -25,6 +25,11 @@ public void validateFileType(MultipartFile file) {
         }
     }
 
+    @Override
+    public boolean isEmptyFileName(String fileName) {
+        return fileName == null || fileName.isEmpty();
+    }
+
     @Override
     public boolean isEmptyFile(MultipartFile file) {
         return file == null || file.isEmpty();

src/main/java/com/somemore/global/imageupload/validator/ImageUploadValidator.java

@@ -9,4 +9,6 @@ public interface ImageUploadValidator {
     void validateFileType(MultipartFile file);
 
     boolean isEmptyFile(MultipartFile file);
+
+    boolean isEmptyFileName(String fileName);
 }

src/test/java/com/somemore/global/imageupload/service/ImageUploadServiceTest.java

@@ -1,9 +1,7 @@
 package com.somemore.global.imageupload.service;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.junit.jupiter.api.Assertions.assertNotNull;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.*;
 import static org.mockito.BDDMockito.given;
 import static org.mockito.Mockito.any;
 import static org.mockito.Mockito.mock;
@@ -17,6 +15,8 @@
 import com.somemore.support.IntegrationTestSupport;
 import java.io.IOException;
 import java.io.InputStream;
+import java.net.URL;
+
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
@@ -28,6 +28,9 @@
 import software.amazon.awssdk.core.sync.RequestBody;
 import software.amazon.awssdk.services.s3.S3Client;
 import software.amazon.awssdk.services.s3.model.PutObjectRequest;
+import software.amazon.awssdk.services.s3.presigner.S3Presigner;
+import software.amazon.awssdk.services.s3.presigner.model.GetObjectPresignRequest;
+import software.amazon.awssdk.services.s3.presigner.model.PresignedGetObjectRequest;
 
 class ImageUploadServiceTest extends IntegrationTestSupport {
 
@@ -76,6 +79,7 @@ void testUploadImage_success() {
     @DisplayName("이미지 형식이 올바르지 않다면 업로드 할 수 없다.")
     @Test
     void testUploadImage_failure() throws IOException {
+
         // given
         when(multipartFile.getInputStream()).thenThrow(new IOException());
 
@@ -88,6 +92,7 @@ void testUploadImage_failure() throws IOException {
     @DisplayName("이미지 파일이 없다면 기본 이미지 링크를 반환한다.")
     @Test
     void uploadImageWithEmptyFile() {
+
         // given
         MultipartFile emptyFile = new MockMultipartFile("file", new byte[0]);
         given(imageUploadValidator.isEmptyFile(emptyFile)).willReturn(true);
@@ -99,4 +104,53 @@ void uploadImageWithEmptyFile() {
         // then
         assertThat(imgUrl).isEqualTo(ImageUploadService.DEFAULT_IMAGE_URL);
     }
+
+    @DisplayName("유효한 파일명으로 사전 서명된 URL을 생성할 수 있다.")
+    @Test
+    void getPresignedUrl_success() {
+
+        // given
+        String filename = "testImage.jpg";
+
+        when(imageUploadValidator.isEmptyFileName(filename)).thenReturn(false);
+
+        S3Presigner mockPresigner = mock(S3Presigner.class);
+        ReflectionTestUtils.setField(imageUploadService, "s3Presigner", mockPresigner);
+
+        PresignedGetObjectRequest mockPresignedRequest = mock(PresignedGetObjectRequest.class);
+        URL mockUrl = mock(URL.class);
+
+        when(mockUrl.toString()).thenReturn("https://test-bucket.s3.amazonaws.com/unique-test-image.jpg");
+        when(mockPresignedRequest.url()).thenReturn(mockUrl);
+        when(mockPresigner.presignGetObject(any(GetObjectPresignRequest.class))).thenReturn(mockPresignedRequest);
+
+        // when
+        String presignedUrl = imageUploadService.getPresignedUrl(filename);
+
+        // then
+        assertNotNull(presignedUrl);
+        assertTrue(presignedUrl.startsWith("https://test-bucket.s3.amazonaws.com/"));
+        assertTrue(presignedUrl.endsWith(".jpg"));
+
+        verify(imageUploadValidator, times(1)).isEmptyFileName(filename);
+        verify(mockPresigner, times(1)).presignGetObject(any(GetObjectPresignRequest.class));
+    }
+
+    @DisplayName("파일명 검증에 실패하면 null을 반환한다.")
+    @Test
+    void getPresignedUrl_invalidFileName() {
+
+        // given
+        String filename = "";
+
+        when(imageUploadValidator.isEmptyFileName(filename)).thenReturn(true);
+
+        // when
+        String presignedUrl = imageUploadService.getPresignedUrl(filename);
+
+        // then
+        assertNull(presignedUrl);
+
+        verify(imageUploadValidator, times(1)).isEmptyFileName(filename);
+    }
 }

src/test/java/com/somemore/global/imageupload/validator/DefaultImageUploadValidatorTest.java

@@ -93,4 +93,43 @@ void shouldThrowExceptionWhenFileTypeIsNull() {
         // then
         assertEquals(ImageUploadException.class, exception.getClass());
     }
+
+    @Test
+    @DisplayName("파일 이름이 비어있는지 확인할 수 있다.")
+    void shouldReturnTrueWhenFileNameIsEmpty() {
+        // given
+        String emptyFileName = "";
+
+        // when
+        boolean isEmptyFileName = imageUploadValidator.isEmptyFileName(emptyFileName);
+
+        // then
+        assertThat(isEmptyFileName).isTrue();
+    }
+
+    @Test
+    @DisplayName("파일 이름이 null이면 true를 반환한다.")
+    void shouldReturnTrueWhenFileNameIsNull() {
+        // given
+        String nullFileName = null;
+
+        // when
+        boolean isEmptyFileName = imageUploadValidator.isEmptyFileName(nullFileName);
+
+        // then
+        assertThat(isEmptyFileName).isTrue();
+    }
+
+    @Test
+    @DisplayName("파일 이름이 비어있지 않으면 false를 반환한다.")
+    void shouldReturnFalseWhenFileNameIsNotEmpty() {
+        // given
+        String validFileName = "testImage.jpg";
+
+        // when
+        boolean isEmptyFileName = imageUploadValidator.isEmptyFileName(validFileName);
+
+        // then
+        assertThat(isEmptyFileName).isFalse();
+    }
 }