Spring Boot + MongoDB Id query

Question

I have a Spring Boot application combined with MongoDB as the persistance layer. I have the following structure:

public class Resource {

@Id
public String Id;
...
}

I also have a ResourceRepository:

@RepositoryRestResource(collectionResourceRel = "resources", path = "resources")
public interface ResourceRepository extends MongoRepository<Resource, String> {
     Resource findById(@Param("Id")String Id);
}

I found online that a way to have the id property returned in the JSON when you perform a GET request like http://localhost:8080/resources/ is to change the id property to Id (uppercase i). Indeed, if the property is lowercase, I don't get back an id field but if I change it to uppercase then I get it. For a reason, I need to get back the id property so I used the uppercase i. So far, so good.

However, when I tried to execute the query findById included in my repository I get an exception:

org.springframework.data.mapping.context.InvalidPersistentPropertyPath: No property id found on app.model.Resource!

If I change the Id property to id (lowercase i) I can execute successfully the /resources/search/findById?id=... GET request.

I tried creating a custom controller with a query that finds and returns a Resource based on the id that is given:

@Controller
@RequestMapping("/resource")
public class ResourceController {

    @Autowired
    MongoOperations mongoOperations;

    @RequestMapping(value="/findById/{resourceId}/", method= RequestMethod.GET)
    @ResponseBody
    public Resource findByResourceId(@PathVariable("resourceId") String resourceId) {
        Resource resource = mongoOperations.findOne(query(Criteria.where("Id").is(resourceId)), Resource.class,"DOJ");
    }
}

but I receive the same error:

org.springframework.data.mapping.context.InvalidPersistentPropertyPath: No property id found on app.model.Resource!

Any idea on how to both have the id property displyed in the JSon and be able to findById?

Look at the error spring data is not able to find property with name id (small i). Your property is Id (capital I). Sprint Data repositories work by convention and are looking for property with name id (small i). — rangalo
– rangalo, Commented Jan 26, 2018 at 14:42
Thanks @rangalo , I understand this however my question is not why I get the error but how can I expose ids and also be able to query using ids. — Thanos
– Thanos, Commented Jan 26, 2018 at 14:54
Change the field Id to id as per convention the field names start with small letters. If you don't want to do this or can't do this then you will have to use custom repositories instead of spring data repositories. — rangalo
– rangalo, Commented Jan 26, 2018 at 14:59

always_a_rookie · Accepted Answer · 2020-11-17 16:39:55Z

1

Well, I found the answer myself. Switch back to lowercase id so findById works and add the following class to the project:

@Configuration
public class SpringDataRestConfiguration extends RepositoryRestConfigurerAdapter  {

    @Override
    public void configureRepositoryRestConfiguration(RepositoryRestConfiguration config) {
        config.exposeIdsFor(Resource.class);
    }
}

As the name of the method suggests, this configuration makes Resource class objects to expose their ids in JSON.

UPDATE: If you are using the latest or relatively latest version of spring-boot, the RepositoryRestConfigurerAdapter class has been deprecated, and the java-doc suggests to use the interface RepositoryRestConfigurer directly.

So your code should look like this:

@Configuration
public class SpringDataRestConfiguration implements RepositoryRestConfigurer  
...

edited Nov 17, 2020 at 16:39

always_a_rookie

4,8801 gold badge30 silver badges51 bronze badges

answered Jan 26, 2018 at 15:11

Thanos

3,6753 gold badges26 silver badges35 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Spring Boot + MongoDB Id query

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related