ExampleAssembler

The ExampleAssembler is responsible for the conversion of entities into representations, essentially mapping data from the ExampleEntity to ExampleRepresentation in a systematic, standardized manner.

This transformation is necessary to decouple the database model from the external model.

• The @Component annotation tells the Spring Framework to auto-detect these classes for dependency injection.

@Component
public class ExampleAssembler
    extends AbstractRepresentationAssembler<ExampleEntity, ExampleRepresentation> {
  @Override
  public @NonNull ExampleRepresentation toModel(@NonNull ExampleEntity entity) {
    return ExampleRepresentation.builder().id(entity.getId()).content(entity.getContent()).build();
  }
}

This class extends AbstractRepresentationAssembler<ExampleEntity, ExampleRepresentation>, which means it inherits the behavior of the abstract base class, but with a specific implementation defined for the toModel() method.

This is an overridden method from the parent AbstractRepresentationAssembler class. It’s designed to convert an instance of ExampleEntity to ExampleRepresentation. Here, @NonNull annotation, provided by the Lombok library, ensures that the entity argument passed to this method cannot be null, preventing possible null pointer exceptions.

The method uses a builder pattern to construct a new ExampleRepresentation object. This builder pattern is a part of the Lombok library that simplifies the construction of complex objects. Here, it’s used to set the id and content of the ExampleRepresentation with the corresponding values from the ExampleEntity