Uploading Retrieving Photos

Watch Code

Building on our previous work with the StorageService, we'll now create a dedicated service for handling photo operations, which will generate unique identifiers for photos and maintain additional metadata about uploaded images.

The Photo Service Interface

Let's start by defining a clear contract for photo operations through an interface.

package com.devtiro.restaurant.services;

import com.devtiro.restaurant.domain.entities.Photo;
import org.springframework.core.io.Resource;
import org.springframework.web.multipart.MultipartFile;

import java.util.Optional;

public interface PhotoService {
    Photo uploadPhoto(MultipartFile file);
    Optional<Resource> getPhotoAsResource(String id);
}

The interface defines two main operations: uploading a new photo and retrieving an existing one.

The uploadPhoto method returns a Photo entity that contains metadata about the uploaded file.

The getPhotoAsResource method returns an Optional<Resource> to handle cases where the photo might not exist.

Implementing the Photo Service

Now let's implement the photo service, leveraging our existing StorageService.

@Service
@RequiredArgsConstructor
public class PhotoServiceImpl implements PhotoService {

    private final StorageService storageService;

    @Override
    public Photo uploadPhoto(MultipartFile file) {
        // Generate a unique ID for the photo
        String photoId = UUID.randomUUID().toString();

        // Store the file and get its URL
        String url = storageService.store(file, photoId);

        // Create and populate the photo entity
        Photo photo = new Photo();
        photo.setUrl(url);
        photo.setUploadDate(LocalDateTime.now());

        return photo;
    }

    @Override
    public Optional<Resource> getPhotoAsResource(String id) {
        return storageService.loadAsResource(id);
    }
}

The implementation delegates the actual file operations to the StorageService we created earlier.

For photo uploads, we generate a unique identifier using UUID to ensure no two photos have the same ID.

We store additional metadata like the upload date, which will be useful for tracking and managing photos.

Summary

Implemented PhotoService interface defining upload and retrieval operations
Created PhotoServiceImpl to manage photo storage and retrieval
Used UUID to generate unique identifiers for photos
Leveraged existing StorageService for file operations