Create Controller

Create ProductDTO

  1. Create a directory named dto and a new file named ProductDto within it.

    Architect

  2. Define the ProductDTO as follows:

public record ProductDto(
    String id, String name, String code, float price, String model,
    @JsonInclude(JsonInclude.Include.NON_NULL)
    String url
) {
    public ProductDto(Product product) {
        this(product.getId(), product.getProductName(), product.getCode(),
                product.getPrice(), product.getModel(), product.getProductUrl());
    }

    static public Product toProduct(ProductDto productDto) {
        Product product = new Product();
        product.setId(product.getId());
        product.setProductName(productDto.name);
        product.setCode(productDto.code());
        product.setModel(productDto.model());
        product.setPrice(productDto.price());
        product.setProductUrl(productDto.url());
        return product;
    }
}

Architect

Create Controller

  1. In the ProductsController class, initialize productsRepository:
    • Declare productsRepository as a dependency injection through the constructor, used to access data from products in the database.
    • Initialize productsRepository in the constructor using @Autowired, allowing Spring to automatically inject productsRepository into the controller.
   private final ProductsRepository productsRepository;

   @Autowired
   public ProductsController(ProductsRepository productsRepository) {
       this.productsRepository = productsRepository;
   }

Architect

  1. Create the getAllProducts method. This method is annotated with @GetMapping, indicating that it handles HTTP GET requests to the specified path (/products). The method includes:

    • Logging the information “Get all products”.
    • Creating an empty list productsDto to store ProductDto objects.
    • Using productsRepository.getAll().items().subscribe(...) to retrieve a list of products from the repository.
    • For each product retrieved from the repository, it creates a corresponding ProductDto and adds it to productsDto.
    • Finally, the method returns a ResponseEntity<List<ProductDto>> containing the created productsDto list with an HTTP status of HttpStatus.OK.
    @GetMapping
public ResponseEntity<List<ProductDto>> getAllProducts() {
    LOG.info("Get all products");
    List<ProductDto> productsDto = new ArrayList<>();

    productsRepository.getAll().items().subscribe(product -> {
        productsDto.add(new ProductDto(product));
    }).join();

    return new ResponseEntity<>(productsDto, HttpStatus.OK);
}

![Architect](/images/8/controller/04.png/?featherlight=false&width=60pc)

5. Create the **getProductById** method. This method is annotated with **@GetMapping("{id}")**, indicating that it handles HTTP GET requests to "/products/{id}", where `{id}` is a path variable.

   - This method retrieves the `id` from the path and uses `productsRepository.getById(id).join()` to wait for and retrieve the `Product` from the repository.
   - If the `product` is not `null`, it returns the `ProductDto` of that product with an HTTP status of `HttpStatus.OK`.
   - If the `product` is `null`, it returns an error message "Product not found" with an HTTP status of `HttpStatus.NOT_FOUND`.

   ```java
   @GetMapping("{id}")
   public ResponseEntity<?> getProductById(@PathVariable("id") String id) {
       Product product = productsRepository.getById(id).join();
       if (product != null) {
           return new ResponseEntity<>(new ProductDto(product), HttpStatus.OK);
       } else {
           return new ResponseEntity<>("Product not found", HttpStatus.NOT_FOUND);
       }
   }

Architect

  1. Create the createProduct method. This method is annotated with @PostMapping, indicating that it handles HTTP POST requests to “/products”.

    • This method creates a Product from the ProductDto sent in the request (productDto), assigns a new id using UUID.randomUUID().toString(), and then saves productCreated to productsRepository using productsRepository.create(productCreated).join().
    • After successfully creating the product, it logs information about the created product and returns the ProductDto of that product with an HTTP status of HttpStatus.CREATED.
   @PostMapping
   public ResponseEntity<ProductDto> createProduct(@RequestBody ProductDto productDto) {
       Product productCreated = ProductDto.toProduct(productDto);
       productCreated.setId(UUID.randomUUID().toString());
       productsRepository.create(productCreated).join();

       LOG.info("Product created - ID: {}", productCreated.getId());
       return new ResponseEntity<>(new ProductDto(productCreated), HttpStatus.CREATED);
   }

Architect

  1. Create the deleteProductById method. This method is annotated with @DeleteMapping("{id}"), indicating that it handles HTTP DELETE requests to “/products/{id}”.

    • This method uses productsRepository.deleteById(id).join() to delete the product from the repository.
    • If the product is successfully deleted (productDeleted is not null), it logs information about the deleted product and returns the ProductDto of that product with an HTTP status of HttpStatus.OK.
    • If no product is found to delete (productDeleted is null), it returns an error message “Product not found” with an HTTP status of HttpStatus.NOT_FOUND..
   @DeleteMapping("{id}")
   public ResponseEntity<?> deleteProductById(@PathVariable("id") String id) {
       Product productDeleted = productsRepository.deleteById(id).join();
       if (productDeleted != null) {
           LOG.info("Product deleted - ID: {}", productDeleted.getId());
           return new ResponseEntity<>(new ProductDto(productDeleted), HttpStatus.OK);
       } else {
           return new ResponseEntity<>("Product not found", HttpStatus.NOT_FOUND);
       }
   }

Architect

  1. Create the updateProduct method. This method is annotated with @PutMapping("{id}"), indicating that it handles HTTP PUT requests to “/products/{id}”.

    • This method updates the information of a product based on the specified id. It uses 88productsRepository.update(…).join()88 to update the product in the repository.
    • If the product is updated successfully, it logs information about the updated product and returns the ProductDto of that product with an HTTP status of 88HttpStatus.OK88.
    • If no product is found to update (productsRepository.update(…) throws a CompletionException), it returns an error message “Product not found” with an HTTP status of HttpStatus.NOT_FOUND.
   @PutMapping("{id}")
   public ResponseEntity<?> updateProduct(@RequestBody ProductDto productDto,
                                          @PathVariable("id") String id) {
       try {
           Product productUpdated = productsRepository
                   .update(ProductDto.toProduct(productDto), id).join();
           LOG.info("Product updated - ID: {}", productUpdated.getId());
           return new ResponseEntity<>(new ProductDto(productUpdated), HttpStatus.OK);
       } catch (CompletionException e) {
           return new ResponseEntity<>("Product not found", HttpStatus.NOT_FOUND);
       }
   }

Architect