[Spring Boot] AWS S3로 파일 저장소 연동하기

build.gradle

implementation 'org.springframework.cloud:spring-cloud-starter-aws:2.2.6.RELEASE'

 

application.properties

cloud.aws.region.static=ap-northeast-2
cloud.aws.stack.auto=false
cloud.aws.s3.bucket=
cloud.aws.credentials.access-key=
cloud.aws.credentials.secret-key=

spring.servlet.multipart.max-file-size: 10MB
spring.servlet.multipart.max-request-size: 10MB

 

S3Config

@Configuration
public class S3Config {
    @Value("${cloud.aws.credentials.access-key}")
    private String accessKey;
    @Value("${cloud.aws.credentials.secret-key}")
    private String secretKey;
    @Value("${cloud.aws.region.static}")
    private String region;

    @Bean
    public AmazonS3Client amazonS3Client() {
        BasicAWSCredentials awsCreds = new BasicAWSCredentials(accessKey,secretKey);
        return (AmazonS3Client) AmazonS3ClientBuilder.standard()
                    .withRegion(region)
                    .withCredentials(new AWSStaticCredentialsProvider(awsCreds))
                    .build();
    }
}

 

S3Uploader

@Component
@RequiredArgsConstructor
public class S3Uploader {
    private final AmazonS3Client amazonS3Client;
    @Value("${cloud.aws.s3.bucket}")
    private String bucket;

    public String uploadFiles(MultipartFile multipartFile, String dirName) throws IOException {
        File uploadFile = convert(multipartFile)  // 파일 변환할 수 없으면 에러
                .orElseThrow(() -> new IllegalArgumentException("error: MultipartFile -> File convert fail"));
        return upload(uploadFile, dirName);
    }

    public String upload(File uploadFile, String filePath) {
        String fileName = filePath + "/" + UUID.randomUUID() + uploadFile.getName();   // S3에 저장된 파일 이름
        String uploadImageUrl = putS3(uploadFile, fileName); // s3로 업로드
        removeNewFile(uploadFile);
        return uploadImageUrl;
    }

    // S3로 업로드
    private String putS3(File uploadFile, String fileName) {
        amazonS3Client.putObject(new PutObjectRequest(bucket, fileName, uploadFile).withCannedAcl(CannedAccessControlList.PublicRead));
        return amazonS3Client.getUrl(bucket, fileName).toString();
    }

    // 로컬에 저장된 이미지 지우기
    private void removeNewFile(File targetFile) {
        if (targetFile.delete()) {
            System.out.println("File delete success");
            return;
        }
        System.out.println("File delete fail");
    }

    // 로컬에 파일 업로드 하기
    private Optional<File> convert(MultipartFile file) throws IOException {
        File convertFile = new File(System.getProperty("user.dir") + "/" + file.getOriginalFilename());
        if (convertFile.createNewFile()) { // 바로 위에서 지정한 경로에 File이 생성됨 (경로가 잘못되었다면 생성 불가능)
            try (FileOutputStream fos = new FileOutputStream(convertFile)) { // FileOutputStream 데이터를 파일에 바이트 스트림으로 저장하기 위함
                fos.write(file.getBytes());
            }
            return Optional.of(convertFile);
        }
        return Optional.empty();
    }
}

 

 

PostController

@RestController
@RequiredArgsConstructor
public class PostController {

    private final S3Uploader s3Uploader;

    @PostMapping("/post")
    public String postImg (@RequestPart(value = "img") MultipartFile multipartFile) throws IOException {
        
        
        return s3Uploader.uploadFiles(multipartFile, "버킷 폴더이름");
    }
}