Spring Data JPA with MVC repository - spring

Question

I am building a Spring repository for some JPA-annotated entities. I have created a repository:
public interface AppRepository extends PagingAndSortingRepository<App, String>
{
}
The App class looks as follows:
#Entity
public class App implements Serializable
{
#Id
private String appId;
#OneToMany(mappedBy = "app")
private List<AgentUser> agentusers;
#OneToMany(mappedBy = "app")
private List<AppFacet> appfacets;
// getters and setters go here
}
where the AgentUser and the AppFacet hold a reference property called app towards an App object. In the AgentUser class, I have changed the RestResource rel:
#Entity
public class AgentUser
{
...
#ManyToOne
#JoinColumn(name = "AppId")
#RestResource(rel = "agentUserToApp", exported = false)
private App app;
// other properties go here
}
I am getting the following error message while querying the /apps path:
org.springframework.http.converter.HttpMessageNotWritableException: Could not write content: Infinite recursion (StackOverflowError) (through reference chain: org.springframework.hateoas.PagedResources["_embedded"]);
Do you know what could be causing it? Please note that I only have one App object in a database, for testing purposes and no other kind of object.
Update
The trace is:
com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:677)
com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:156)
com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:129)
com.fasterxml.jackson.databind.ObjectMapper.writeValue(ObjectMapper.java:2240)
org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:231)
org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:208)
org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:161)
org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:101)
org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:167)
And after that, a lot of:
org.springframework.data.mapping.model.BasicPersistentEntity.doWithAssociations(BasicPersistentEntity.java:352)
org.springframework.data.rest.webmvc.mapping.LinkCollectingAssociationHandler.doWithAssociation(LinkCollectingAssociationHandler.java:101)

Answer 1

The problem resides in that, whenever you have links to some entities, you must implement a repository for that entity too, in order to generate the proper links.