record classes in java скачать в хорошем качестве

record classes in java

Java 16 record class.. replacement of lombok.. it will write constructors, getters , (no setters since it's by default immutable)hash code, equal, tostriing , everything for you!!! Why records are a bad fit for JPA entities 1)records are immutable and it should not be used as JPA entity 2)All fields are final 3)JPA and Hibernate need to set values like id, createdAt, updatedAt after object creation 4)Records do not support a no-args constructor Hibernate uses proxies and bytecode enhancement Records are final Hibernate cannot create proxy subclasses Lifecycle annotations don’t work properly Annotations like CreationTimestamp and UpdateTimestamp rely on mutability Even though some experimental hacks exist, records should not be used as JPA entities in production systems. Entities are mutable classes Records are used for DTOs only This separation is considered best practice in modern Spring Boot projects. Best Industry standerd Rules: 1)controller should accept DTO and not entity 2)Controller Returns DTO Not Entity 3)Records should not be used as Entity, because all fields are final , and we want to update them actually 4)record classes are perfect example of DTO which we can use as request and response for controller and service layer steps: 1)dont use @Data annotation for Product entity , it will generate hashcode and equals which can cause issues with JPA entities. instead, use @Getter and @Setter annotations 2)Step 2: Create Record DTOs (Best Use Case for Records) Request DTO using record public record ProductRequest( String name, double price ) {} Response DTO using record public record ProductResponse( Long id, String name, double price, LocalDateTime createdAt, LocalDateTime updatedAt ) {} This is where records shine Immutable Clean Perfect for API contracts Step 3: Service Layer Mapping service methods should accept DTO request create a new entity class nad get details from request and set to entity and return a DTO example: public ProductResponse createProduct(ProductRequest request) { Product product = new Product(); product.setName(request.name()); product.setPrice(request.price()); Product saved = repository.save(product); return new ProductResponse( saved.getId(), saved.getName(), saved.getPrice(), saved.getCreatedAt(), saved.getUpdatedAt() ); } Step 4: Controller Returns DTO Not Entity example: @PostMapping public ProductResponse create(@RequestBody ProductRequest request) { return service.createProduct(request); }