[feat/#50] presigned url 구현

src/main/java/com/moplus/moplus_server/domain/problem/controller/ImageUploadController.java

@@ -0,0 +1,39 @@
+package com.moplus.moplus_server.domain.problem.controller;
+
+import com.moplus.moplus_server.domain.problem.domain.problem.ProblemImageType;
+import com.moplus.moplus_server.domain.problem.service.ImageUploadService;
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+@Tag(name = "이미지 업로드 API", description = "이미지 업로드 관련 API")
+@RestController
+@RequiredArgsConstructor
+@RequestMapping("/api/v1/images")
+public class ImageUploadController {
+
+    private final ImageUploadService imageUploadService;
+
+    @Operation(summary = "이미지 업로드를 위한 presigned URL 발급")
+    @GetMapping("/problem/{problemId}/presigned-url")
+    public ResponseEntity<String> getProblemImagePresignedUrl(
+            @PathVariable("problemId") String problemId,
+            @RequestParam(value = "image-type") ProblemImageType imageType) {
+        String presignedUrl = imageUploadService.generateProblemImagePresignedUrl(problemId, imageType);
+        return ResponseEntity.ok(presignedUrl);
+    }
+
+    @Operation(summary = "이미지 업로드 완료 후 URL 조회")
+    @GetMapping("/{fileName}")
+    public ResponseEntity<String> getImageUrl(
+            @PathVariable("fileName") String fileName) {
+        String imageUrl = imageUploadService.getImageUrl(fileName);
+        return ResponseEntity.ok(imageUrl);
+    }
+}

src/main/java/com/moplus/moplus_server/domain/problem/domain/problem/ProblemImageType.java

@@ -0,0 +1,19 @@
+package com.moplus.moplus_server.domain.problem.domain.problem;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@Getter
+@RequiredArgsConstructor
+public enum ProblemImageType {
+    MAIN_PROBLEM("main-problem", "문제 이미지"),
+    MAIN_ANALYSIS("main-analysis", "분석 이미지"),
+    MAIN_HANDWRITING_EXPLANATION("main-handwriting-explanation", "손글씨 설명 이미지"),
+    READING_TIP("reading-tip", "읽기 팁 이미지"),
+    SENIOR_TIP("senior-tip", "선배 팁 이미지"),
+    PRESCRIPTION("prescription", "처방전 이미지"),
+    CHILD_PROBLEM("child-problem", "하위 문제 이미지");
+
+    private final String type;
+    private final String description;
+} 

src/main/java/com/moplus/moplus_server/domain/problem/repository/ProblemRepository.java

@@ -16,6 +16,12 @@ default void existsByIdElseThrow(Long id) {
         }
     }
 
+    default void existsByProblemAdminIdElseThrow(ProblemAdminId problemAdminId) {
+        if (!existsByProblemAdminId(problemAdminId)) {
+            throw new NotFoundException(ErrorCode.PROBLEM_NOT_FOUND);
+        }
+    }
+
     default Problem findByIdElseThrow(Long id) {
         return findById(id).orElseThrow(() -> new NotFoundException(ErrorCode.PROBLEM_NOT_FOUND));
     }

src/main/java/com/moplus/moplus_server/domain/problem/service/ImageUploadService.java

@@ -0,0 +1,39 @@
+package com.moplus.moplus_server.domain.problem.service;
+
+import com.amazonaws.HttpMethod;
+import com.moplus.moplus_server.domain.problem.domain.problem.ProblemAdminId;
+import com.moplus.moplus_server.domain.problem.domain.problem.ProblemImageType;
+import com.moplus.moplus_server.domain.problem.repository.ProblemRepository;
+import com.moplus.moplus_server.global.utils.s3.S3Util;
+import java.util.UUID;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+
+@Service
+@RequiredArgsConstructor
+public class ImageUploadService {
+
+    private static final String PROBLEM_IMAGE_PREFIX = "problems/";
+    private final S3Util s3Util;
+    private final ProblemRepository problemRepository;
+
+    public String generateProblemImagePresignedUrl(String problemId, ProblemImageType imageType) {
+        problemRepository.existsByProblemAdminIdElseThrow(new ProblemAdminId(problemId));
+        String fileName = generateProblemImageFileName(problemId, imageType);
+        return s3Util.getS3PresignedUrl(fileName, HttpMethod.PUT);
+    }
+
+    private String generateProblemImageFileName(String problemId, ProblemImageType imageType) {
+        String uuid = UUID.randomUUID().toString();
+        return String.format("%s%s/%s/%s.jpg",
+                PROBLEM_IMAGE_PREFIX,
+                problemId,
+                imageType.getType(),
+                uuid
+        );
+    }
+
+    public String getImageUrl(String fileName) {
+        return s3Util.getS3ObjectUrl(fileName);
+    }
+} 

src/main/java/com/moplus/moplus_server/global/error/exception/ErrorCode.java

@@ -28,10 +28,10 @@ public enum ErrorCode {
     PRACTICE_TEST_NOT_FOUND(HttpStatus.NOT_FOUND, "해당 모의고사를 찾을 수 없습니다"),
 
     //문항
-    PROBLEM_NOT_FOUND(HttpStatus.NOT_FOUND, "해당 문제를 찾을 수 없습니다"),
-    PROBLEM_ALREADY_EXIST(HttpStatus.CONFLICT, "해당 문제는 이미 존재합니다"),
-    INVALID_MULTIPLE_CHOICE_ANSWER(HttpStatus.BAD_REQUEST, "객관식 문제의 정답은 1~5 사이의 숫자여야 합니다"),
-    INVALID_SHORT_NUMBER_ANSWER(HttpStatus.BAD_REQUEST, "주관식 문제의 정답은 0~999 사이의 숫자여야 합니다"),
+    PROBLEM_NOT_FOUND(HttpStatus.NOT_FOUND, "해당 문항을 찾을 수 없습니다"),
+    PROBLEM_ALREADY_EXIST(HttpStatus.CONFLICT, "해당 문항는 이미 존재합니다"),
+    INVALID_MULTIPLE_CHOICE_ANSWER(HttpStatus.BAD_REQUEST, "객관식 문항의 정답은 1~5 사이의 숫자여야 합니다"),
+    INVALID_SHORT_NUMBER_ANSWER(HttpStatus.BAD_REQUEST, "주관식 문항의 정답은 0~999 사이의 숫자여야 합니다"),
     INVALID_CONFIRM_PROBLEM(HttpStatus.BAD_REQUEST, "유효하지 않은 문항들 : "),
     INVALID_DIFFICULTY(HttpStatus.BAD_REQUEST, "난이도는 1~10 사이의 숫자여야 합니다"),
 

src/main/java/com/moplus/moplus_server/global/utils/s3/S3Util.java

@@ -1,10 +1,13 @@
 package com.moplus.moplus_server.global.utils.s3;
 
+import com.amazonaws.HttpMethod;
 import com.amazonaws.services.s3.AmazonS3;
+import com.amazonaws.services.s3.model.GeneratePresignedUrlRequest;
 import com.amazonaws.services.s3.model.PutObjectRequest;
 import com.moplus.moplus_server.global.error.exception.ErrorCode;
 import com.moplus.moplus_server.global.error.exception.NotFoundException;
 import java.io.File;
+import java.util.Date;
 import lombok.RequiredArgsConstructor;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Component;
@@ -29,5 +32,24 @@ public String getS3ObjectUrl(String fileName) {
         return amazonS3.getUrl(bucketName, fileName).toString();
     }
 
+    public String getS3PresignedUrl(String fileName, HttpMethod httpMethod) {
+
+        GeneratePresignedUrlRequest generatePresignedUrlRequest =
+                new GeneratePresignedUrlRequest(bucketName, fileName)
+                        .withMethod(httpMethod)
+                        .withExpiration(getPreSignedUrlExpiration());
+
+        return amazonS3.generatePresignedUrl(generatePresignedUrlRequest).toString();
+    }
+
+    private Date getPreSignedUrlExpiration() {
+        final int PRESIGNED_EXPIRATION = 1000 * 60 * 30; //30분
+
+        Date expiration = new Date();
+        var expTimeMillis = expiration.getTime();
+        expTimeMillis += PRESIGNED_EXPIRATION;
+        expiration.setTime(expTimeMillis);
+        return expiration;
+    }
 
 }