Download the Enums Collection with Google Data Warehouse

Question

I am using a Goole application datastore with Java and trying to load an object with an enumeration list. Each time I load an object, List is NULL. An object

@PersistenceCapable(identityType = IdentityType.APPLICATION)
public class ObjectToSave {

    @PrimaryKey
    @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
    private Long id;

    @Persistent
    private List<AnEnum> anEnumList;

    //public getters and setters
}

The listing is simple

public enum AnEnum {
    VALUE_1,
    VALUE_2;
}

Code to save

ObjectToSave objectToSave = new ObjectToSave();
List<AnEnum> anEnumList = new ArrayList<AnEnum>();
anEnumList.add(AnEnum.VALUE_1);
objectToSave.setAnEnumList(anEnumList);
PersistenceManager pm = pmfInstance.getPersistenceManager();
try {
    pm.makePersistent(objectToSave);
} finally {
    pm.close();
}

Download Code -

PersistenceManager pm = pmfInstance.getPersistenceManager();
try {
    Key key = KeyFactory.createKey(ObjectToSave.class.getSimpleName(), id);
    ObjectToSave objectToSave = pm.getObjectById(ObjectToSave.class, key);
} finally {
    pm.close();
}

I can view the data in the data warehouse using http: // localhost: 8080 / _ah / admin and see that my list is saved, but it does not exist when the object is loaded.

I created my project with the Eclipse plugin and did not make any changes to the data warehouse settings, as far as I know. So why id my Enum list null?

Answer 1

, "" , . JDO. DFG "" PM.

- (DataNucleus)

Answer 2

ObjectToSave? null, , () List<AnEnum> anEnumList, .