Lab#SB00-7: Styling

Spring Boot Library Management API Rest and NoSQL-MongoDB refartor

Spring Boot

📘 Spring Boot Lab#SB00-7: API Rest and NoSQL-MongoDB: refactor

1 Overview

1.1 Clean and Improve Code for Book Image REST Controller in Spring Boot

Here are some suggestions for cleaning up and improving the code:

• Use descriptive and meaningful variable names:
  • Change bookImageRepository to repository or imageRepo.
  • Change bookImage to image.
  • Change optionalBookImage to optionalImage.
• Use constructor injection instead of field injection for better testability and maintainability.
  • Remove the @Autowired annotation and add a constructor that takes BookImageRepository as a parameter.
  • Initialize the bookImageRepository field with the constructor parameter.
• Use try-with-resources for handling resources that need to be closed, such as the MultipartFile.
• Extract common code into private methods to reduce duplication.
• Add validation to ensure that required parameters are not null or empty.
• Use Java 8 Optional methods instead of calling .get() and checking for null.
• Add error handling and return appropriate error responses.
• Use HTTP verbs consistently and according to their intended purpose.
• Use ResponseEntity<T> to return responses with the appropriate HTTP status codes and headers.

Here’s an updated version of the code:

@RestController
@RequestMapping("api/image")
public class BookImageRestController {

    private final BookImageRepository imageRepo;

    public BookImageRestController(BookImageRepository imageRepo) {
        this.imageRepo = imageRepo;
    }

    @PostMapping("upload")
    public ResponseEntity<BookImage> saveBookImage(@RequestParam String name, @RequestParam MultipartFile file) throws IOException {
        if (name == null || name.trim().isEmpty() || file == null) {
            return ResponseEntity.badRequest().build();
        }
        try (InputStream inputStream = file.getInputStream()) {
            BookImage image = new BookImage();
            image.setName(name);
            image.setImage(new Binary(inputStream.readAllBytes()));
            BookImage savedImage = imageRepo.save(image);
            return ResponseEntity.ok(savedImage);
        }
    }

    @GetMapping("/{id}")
    public ResponseEntity<byte[]> getBookImage(@PathVariable String id) {
        Optional<BookImage> optionalImage = imageRepo.findById(id);
        if (optionalImage.isPresent()) {
            BookImage image = optionalImage.get();
            HttpHeaders headers = new HttpHeaders();
            headers.setContentType(MediaType.IMAGE_JPEG);
            return ResponseEntity.ok().headers(headers).body(image.getImage().getData());
        } else {
            return ResponseEntity.notFound().build();
        }
    }

    @PutMapping("/{id}")
    public ResponseEntity<BookImage> updateBookImage(@PathVariable String id, @RequestParam String name, @RequestParam MultipartFile file) throws IOException {
        if (name == null || name.trim().isEmpty() || file == null) {
            return ResponseEntity.badRequest().build();
        }
        Optional<BookImage> optionalImage = imageRepo.findById(id);
        if (optionalImage.isPresent()) {
            try (InputStream inputStream = file.getInputStream()) {
                BookImage image = optionalImage.get();
                image.setName(name);
                image.setImage(new Binary(inputStream.readAllBytes()));
                BookImage updatedImage = imageRepo.save(image);
                return ResponseEntity.ok(updatedImage);
            }
        } else {
            return ResponseEntity.notFound().build();
        }
    }

    @DeleteMapping("/{id}")
    public ResponseEntity<Void> deleteBookImage(@PathVariable String id) {
        Optional<BookImage> optionalImage = imageRepo.findById(id);
        if (optionalImage.isPresent()) {
            imageRepo.delete(optionalImage.get());
            return ResponseEntity.ok().build();
        } else {
            return ResponseEntity.notFound().build();
        }
    }
}