Accepting a Spring Data REST URI in custom controller

Question

I have a Spring Data Rest webmvc application that I'd like to add some custom functionality to for batch operations.

I've created a controller, and blended it into the uri namespace, but I'd like for it to be able to accept URI's like the custom /search queries do, rather than simply an ID.

I have tried registering a custom <String, Long> converter (my entity has a Long ID type, but that seems to get ignored. Is there any way to configure my controller such that it adopts that behavior from the auto-implemented SDR controllers?

Even if there is some sort of method I can call that will auto-resolve a URI to an entity, that would work just as well (as I can then simply accept a String in my controller)

Here's where I'm at.

@Configuration
public class CustomWebConfiguration extends WebMvcConfigurationSupport {

    //irrelevant code omitted

    @Bean
    public DomainClassConverter<?> domainClassConverter() {
        DomainClassConverter<FormattingConversionService> dc = new DomainClassConverter<FormattingConversionService>(mvcConversionService());
        return dc;
    }

    @Override
    public void addFormatters(FormatterRegistry registry) {
          registry.addConverter(String.class, Long.class, testConverter());
    }

    @Bean 
    Converter<String, Long> testConverter() {
        return new Converter<String, Long>() {

            @Override
            public Long convert(String source) {
                //this code does _not_ get run at any point
                if (source.indexOf('/') == -1) { return Long.parseLong(source); }

                source = source.substring(source.lastIndexOf('/') + 1);
                Long id = Long.parseLong(source);

                return id;
            }   
        };
    }
}

SDR Config

@Configuration
@EnableHypermediaSupport(type = { HypermediaType.HAL })
public class CustomRestConfiguration extends RepositoryRestMvcConfiguration {

    @Override
    public RepositoryRestConfiguration config() {
      RepositoryRestConfiguration config = super.config();
      config.setBasePath("/api");
      config.exposeIdsFor(ApplicationMembership.class);
      return config;
    }


}

And my (contrived) controller:

ApplicationType is one of my entities that are correctly managed by SDR/repository magic

@BasePathAwareController
@RepositoryRestController
@RequestMapping("applications/special")
public class ApplicationExtensionController {
    @RequestMapping("a")
    public ResponseEntity<?> reply(@RequestParam("type") ApplicationType type) {
        return new ResponseEntity<String>(type.getIcon(), HttpStatus.OK);
    }
}

I've looked around quite a bit but can't quite manage to make anything work. When I create a <String, ApplicationType> converter that utilizes the repository, it also does not get called, as the DomainClassConverter just calls its underlying <String, Long> converter (which obviously fails, as it cannot correctly parse out types/1 into a long.

Appreciate the help!

Forgot to mention

• Spring Data Rest 2.4.0
• Spring HATEOAS 0.19.0
• Spring 4.2.1

Using JPA repositories

Answer 1

As it turns out, I was on the right track with adding a converter, unfortunately I was doing it in the wrong configuration method.

I was able to get the desired functionality by moving my testConverter() bean to the RepositoryRestMvcConfiguration extension config class and then adding

@Override
public void configureConversionService(ConfigurableConversionService service) {
    service.addConverter(testConverter());
}

And working as intended. I feel a bit silly now for throwing that in the wrong spot in the first place, but hopefully this will help someone else out!