Add S3 bucket management and file upload/download features

pom.xml

@@ -31,6 +31,11 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-log4j2</artifactId>
         </dependency>
+        <dependency>
+            <groupId>software.amazon.awssdk</groupId>
+            <artifactId>s3</artifactId>
+            <version>2.25.70</version>
+        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>

src/main/java/com/app/config/AwsS3Config.java

@@ -0,0 +1,45 @@
+package com.app.config;
+
+
+import lombok.extern.log4j.Log4j2;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import software.amazon.awssdk.auth.credentials.AwsBasicCredentials;
+import software.amazon.awssdk.auth.credentials.StaticCredentialsProvider;
+import software.amazon.awssdk.core.client.config.ClientOverrideConfiguration;
+import software.amazon.awssdk.regions.Region;
+import software.amazon.awssdk.services.s3.S3Client;
+
+@Configuration
+@ConditionalOnProperty(name = "aws.s3.enabled", havingValue = "true")
+@Log4j2
+public class AwsS3Config {
+
+    @Value("${aws.s3.region:us-east-1}")
+    private String awsRegion;
+    @Value("${aws.s3.accessKeyId:us-east-1}")
+    private String accessKeyId;
+    @Value("${aws.s3.secretAccessKey}")
+    private String secretAccessKey;
+
+    @Bean
+    public S3Client s3Client() {
+        try {
+            log.info("Trying to S3Client create.");
+            return S3Client.builder()
+                    .region(Region.of(awsRegion))
+                    .credentialsProvider(StaticCredentialsProvider.create(AwsBasicCredentials.create(accessKeyId, secretAccessKey)))
+                    .overrideConfiguration(ClientOverrideConfiguration.builder()
+                            .retryPolicy(r -> r.numRetries(3))
+                            .build())
+                    .build();
+        } catch (Exception e) {
+            log.error("Failed to create S3Client.", e);
+            throw e;
+        } finally {
+            log.info("S3Client created successfully.");
+        }
+    }
+}

src/main/java/com/app/controller/S3Controller.java

@@ -0,0 +1,88 @@
+package com.app.controller;
+
+import com.app.service.S3Service;
+import lombok.RequiredArgsConstructor;
+import org.springframework.core.io.InputStreamResource;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+import org.springframework.web.multipart.MultipartFile;
+import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.List;
+import java.util.Map;
+import java.util.zip.ZipOutputStream;
+
+@RestController
+@RequiredArgsConstructor
+@RequestMapping("/api/files")
+public class S3Controller {
+
+    private final S3Service s3Service;
+
+    @PostMapping("/upload")
+    public ResponseEntity<String> uploadFile(@RequestPart("file") MultipartFile file,
+                                             @RequestParam(value = "isReadPublicly", defaultValue = "false") boolean isReadPublicly) {
+        boolean isUploaded = s3Service.uploadFile(file, isReadPublicly);
+        if (isUploaded) {
+            return ResponseEntity.ok("File uploaded successfully: " + file.getOriginalFilename());
+        } else {
+            return ResponseEntity.status(500).body("Failed to upload file: " + file.getOriginalFilename());
+        }
+    }
+
+    @GetMapping("/download/{key}")
+    public ResponseEntity<InputStreamResource> downloadFile(@PathVariable String key) {
+        InputStream fileStream = s3Service.downloadFileAsStream(key);
+        InputStreamResource resource = new InputStreamResource(fileStream);
+        return ResponseEntity.ok()
+                .header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=" + key)
+                .contentType(MediaType.APPLICATION_OCTET_STREAM)
+                .body(resource);
+    }
+
+    @GetMapping("/create-bucket")
+    public ResponseEntity<String> createBucket(@RequestParam String bucketName) {
+        return ResponseEntity.ok(s3Service.createBucket(bucketName));
+    }
+
+    @GetMapping("/bucket-list")
+    public ResponseEntity<List<String>> getBucketList() {
+        return ResponseEntity.ok(s3Service.getBucketList());
+    }
+
+    @GetMapping("/list-buckets-with-regions")
+    public Map<String, String> listBucketsWithRegions() {
+        return s3Service.listBucketsWithRegions();
+    }
+
+    @GetMapping("/download-all-files-zip")
+    public ResponseEntity<StreamingResponseBody> downloadAllFilesAsZip(@RequestParam String bucketName) {
+
+        // Streaming response to handle large files efficiently
+        StreamingResponseBody responseBody = outputStream -> {
+            try (ZipOutputStream zos = new ZipOutputStream(outputStream)) {
+                s3Service.streamAllFilesAsZip(bucketName, zos);
+            } catch (IOException e) {
+                throw new RuntimeException("Error while streaming files to output stream", e);
+            }
+        };
+
+        // Set headers for ZIP file download
+        HttpHeaders headers = new HttpHeaders();
+        headers.add("Content-Disposition", "attachment; filename=all-files.zip");
+        headers.add("Content-Type", "application/zip");
+
+        return new ResponseEntity<>(responseBody, headers, HttpStatus.OK);
+    }
+
+    @GetMapping("/move-files")
+    public String moveFiles(@RequestParam String sourceBucketName, @RequestParam String destinationBucketName) {
+        s3Service.moveFiles(sourceBucketName, destinationBucketName);
+        return "Files are being moved from " + sourceBucketName + " to " + destinationBucketName;
+    }
+}

src/main/java/com/app/service/S3Service.java

@@ -0,0 +1,25 @@
+package com.app.service;
+
+import org.springframework.web.multipart.MultipartFile;
+
+import java.io.InputStream;
+import java.util.List;
+import java.util.Map;
+import java.util.zip.ZipOutputStream;
+
+public interface S3Service {
+
+    boolean uploadFile(MultipartFile file, boolean isReadPublicly);
+
+    InputStream downloadFileAsStream(String key);
+
+    String createBucket(String bucketName);
+
+    List<String> getBucketList() throws RuntimeException;
+
+    Map<String, String> listBucketsWithRegions();
+
+    void streamAllFilesAsZip(String bucketName, ZipOutputStream zos);
+
+    void moveFiles(String sourceBucketName, String destinationBucketName);
+}