S3Controller.java

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;
    }
}