Expose Custom repository via REST [DATAREST-845]

urbanq opened DATAREST-845 and commented

it would be nice to have a possibility to expose methods from Custom repositoy via REST.

I found a workaround, that might be helpful:

// extend org.springframework.data.repository.core.support.DefaultRepositoryInformation
class DefaultRepositoryInformation implements RepositoryInformation {
...
	public Set<Method> getCustomQueryMethods() {
		Set<Method> result = new HashSet<>( );
		for (Method method : getRepositoryInterface().getMethods()) {
			method = ClassUtils.getMostSpecificMethod(method, getRepositoryInterface());
			if (isCustomMethod(method)) {
				result.add(method);
			}
		}
		return Collections.unmodifiableSet(result);
	}
...
}

and:

// extend org.springframework.data.rest.core.mapping.RepositoryResourceMappings
public class RepositoryResourceMappings extends PersistentEntitiesResourceMappings {
...
	@Override
	public SearchResourceMappings getSearchResourceMappings( Class<?> domainType ) {
		Assert.notNull(domainType, "Type must not be null!");

		if (searchCache.containsKey(domainType)) {
			return searchCache.get(domainType);
		}

		RepositoryInformation repositoryInformation = repositories.getRepositoryInformationFor(domainType);
		List<MethodResourceMapping> mappings = new ArrayList<MethodResourceMapping>();
		ResourceMetadata resourceMapping = getMetadataFor(domainType);

		if (resourceMapping.isExported()) {
			for (Method queryMethod : repositoryInformation.getQueryMethods()) {
				RepositoryMethodResourceMapping methodMapping = new RepositoryMethodResourceMapping(queryMethod,
						resourceMapping, repositoryInformation);
				if (methodMapping.isExported()) {
					mappings.add(methodMapping);
				}
			}
			//////////////////////////////////
			// method BODY EXTENSION STARTS //
			for ( Method queryMethod : repositoryInformation.getCustomQueryMethods( ) ) {
				RepositoryMethodResourceMapping methodMapping = new RepositoryMethodResourceMapping( queryMethod,
						resourceMapping, repositoryInformation );
				if ( methodMapping.isExported( ) ) {
					mappings.add( methodMapping );
				}
			}
			// method BODY EXTENSION ENDS   //
			//////////////////////////////////
		}

		SearchResourceMappings searchResourceMappings = new SearchResourceMappings(mappings);
		searchCache.put(domainType, searchResourceMappings);
		return searchResourceMappings;
	}
...
}

Reference URL: http://stackoverflow.com/questions/21116539/custom-jpa-repository-method-published-by-spring-data-rest

Start by reading DefaultRepositoryInformation and RepositoryResourceMappings, especially getCustomQueryMethods and getSearchResourceMappings, along with the provided workaround. Determine how custom repository methods should be included in REST search mappings, then verify that exposed custom methods are available through the REST API and do not disrupt existing query mappings.