Spring Data Neo4j - Handling simple objects as NodeEntity properties

[dreamage]

Hi,

I'm just playing around with spring-data neo4j ... Suppose I have a Profile class containing a set of Address

@NodeEntity
class Profile {

@GraphId Long id;
String name;
Set<Address> addresses;

}

class Address {

String doorNumber;
String street;
String city;

}

I want to be able to build a Profile object, and using a ProfileRepository, call repository.save(myProfile) and have the addresses automatically saved. But Address is a simple object. Do I have to make Address an NodeEntity and give it an ID property ? I tried it and when I get back the Profile object back from the repository, there is one address in the list and all the fields are null except ID.

What are my options ?

Thanks

[MichaelHunger]

You can add a Spring-Converter to your spring config which is able to convert between Address and String e.g to JSON.

// Could be either a GenericConverter or a Converter<Address,String> + Converter<String,Address>

<bean id="conversionService" class="org.springframework.context.support.ConversionServiceFactoryBean">
        <property name="converters">
            <set>
                <bean class="org.example.converter.AddressToStringConverter"/>
            </set>
        </property>
    </bean>

Michael

[dreamage]

Thanks Michael.
I will try the conversion solution, but I still have a problem using both classes (Profile, Address) as NodeEntities. The case is simpler now, Profile only contains one Address annotated with @RelatedTo.

@NodeEntity
class Profile {

@GraphId Long id;
String name;
@RelatedTo
Address address;

}
@NodeEntity
class Address {

@GraphId Long id;
String doorNumber;
String street;
String city;

}

If I retrieve a profile by id and call profile.getAddress, the Address returned only have the id property set, everything else is null. If I retrieve the Address object directly by id using the AddressRepository, all the data is there. It's working fine in the advanced aspectj mode, but when using the simpler pojo mode, I get a bunch of null fields. Any thoughts ?

[dreamage]

I created a small project with a test to illustrate the problem.

https://github.com/dreamagex/neo4j-profileaddress-test

[MichaelHunger]

If you use simple mapping mode, you have to add @Fetch to the Address or the Collection<Address> field to be loaded eagerly.

Sorry for not seeing that as the issue immediately.


Michael

[dreamage]

I thought the address field would have been replaced with a proxy for lazy loading ? Because the way I see it, if you don't put @Fetch on a field, it's pretty useless, isn't it ?

[MichaelHunger]

I didn't want to go into the ugly realm of lazy proxies.

You can always load those objects/collections with template.fetch() later if you need them.

Michael

[bytor99999]

You know, I have tried template.fetch before and that didn't load my associated objects. I had to do a separate Cypher query to get the associated objects myself.

Mark

[MichaelHunger]

Do you have a test-case for that?

It should do it.

Michael

[dreamage]

I updated my example with Neo4jTemplate.fetch and it's working just fine. Thanks Michael.