Spring Data REST，QueryDSL和HashMaps - 在引用HashMap属性时从URL中为Null谓词

Question

I have an entity object that I'm persisting in MongoDB using Spring Data MongoDB and exposing a REST API to query it. The Entity looks like the following :

Entity.java

 @Document
 public class Entity {
      @Id
      String id;
      Map<String, String> properties;
   }

Corresponding Spring Data repository is as below. It leverages Spring Data MongoDB's integration with QueryDsl:

EntityRepository.java

public interface EntityRepository extends MongoRepository<Entity, String>
                                         ,QueryDslPredicateExecutor<Entity> {
}

Here's the controller through which I query the stored Entities:

EntityController.java

@RestController
@RequestMapping(value = "/entities")
public class EntityController {

    private static final Logger logger = LoggerFactory.getLogger(EntityController.class);

    @Autowired
    EntityRepository entityRepository;

    @RequestMapping(method = RequestMethod.GET)
    public Page<Entity> findAllEntities(Pageable pageable) throws ResourceQueryException {
        return entityRepository.findAll(pageable);
    }

    @RequestMapping(method = RequestMethod.GET, value = "/q")
    public Page<Entity> filterEntities(
            @QuerydslPredicate(root = Entity.class) Predicate predicate,
            Pageable pageable) {
        return entityRepository.findAll(predicate,pageable);
    }

}

When I hit the url localhost:8080/entities/q?id=xxx it works as expected. However, when I hit the url localhost:8080/entities/q?properties.p1=v1 (query keys and values of the Map property), I get a null Predicate in my method, due to which all Entities are being returned.

How do I get this to work properly?

Answer 1

You should store your properties field as List of key-value pairs then it would be possible to search in it.

Your query should work with next structure:

{  id : "1233454",
   properties : [ 
        { "key : "key", "value" : "value" }
   ]
}