How to add custom methods to Spring Data Rest JPA implementation and leverage HATEOS support?

Question

I have a Spring Data Rest Repository controller that utilizes JPA for the query implementation, and I need to add some custom query methods that cannot be done using the sta

Answer 1

A simple implementation could look like this:

@BasePathAwareController
class CustomInvocationsController implements ResourceProcessor {

  private final YourRepository repository;

  public CustomInvocationsController(YourRepository repository) {
    this.repository = repository;
  }

  @RequestMapping(…)
  ResponseEntity handleRequest(PersistentEntityResourceAssembler assembler)

    // invoke repository
    // Use assembler to build a representation
    // return ResponseEntity
  }

  @Override
  public RepositorySearchesResource process(RepositorySearchesResource resource) {
    // add Link to point to the custom handler method
  }
}

A few things to note:

• using @BasePathAwareController instead of a plain @Controller makes sure whatever you're mapping the handler method to, it will consider the base path you've configured on Spring Data REST, too.
• within the request mapping, use everything you already know from Spring MVC, choose an appropriate HTTP method.
• PersistentEntityResourceAssembler basically abstracts setting up a representation model within a PersistentEntityResource so that the Spring Data REST specific treatment of associations etc. kicks in (associations becoming links etc.
• implement ResourceProcessor to post-process RepositorySearchesResource which is returned for the resource rendering all searches. Currently, there's no way to determine which domain type that resource was rendered. I filed and fixed DATAREST-515 to improve that.