Children are not fetch with Parent in jdo - google-app-engine

Question

i am using gwt with jdo datanucleus. i have requirement to get child with parent. but i am not getting child when access parent.
my code is as following
my parent class is
#PersistenceCapable(identityType = IdentityType.APPLICATION, table = "user")
public class User implements Serializable {
private static final long serialVersionUID = 2660867968471555842L;
#PrimaryKey
#Persistent
private String email;
#Persistent(defaultFetchGroup = "true",mappedBy="user")
private UserProfile profile;
public User() {}
public User(String email) {
this.email = email;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public UserProfile getProfile() {
return profile;
}
public void setProfile(UserProfile profile) {
this.profile = profile;
}
}
and my child class is
#PersistenceCapable(identityType = IdentityType.APPLICATION,table = "user_profile")
public class UserProfile implements Serializable {
private static final long serialVersionUID = -6818036410894395030L;
#PrimaryKey
#Persistent(defaultFetchGroup="true")
private User user;
#Persistent
private String name;
public UserProfile() {}
public UserProfile(User user) {
this.user = user;
user.setProfile(this);
}
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
i am fetching data by following query
PersistenceManager pm = PMF.get().getPersistenceManager();
User user=null;
try{
String userId ="abc#abc.com";
Query userQuery = pm.newQuery(User.class);
userQuery.setFilter("email == '" + userId + "'");
userQuery.setUnique(true);
user = (User) userQuery.execute();
} catch (Exception e) {
throw new IllegalAccessError("Failed to get the User..");
}finally{
pm.close();
}
but i am getting userprofile null in object user.
where is the problem ?
how to load children with parent ?

Answer 1

I'm not sure if you found your answer, but for those that stumble across this I just wanted to share how I got it working.
#PersistenceCapable(detachable = "true")
#FetchGroup(name = "fooGroup", members = { #Persistent(name = "list") })
public class ParentClass {
#Persistent(mappedBy = "parent")
#Element(dependent = "true") //can not exist without parent
private List<ChildClass> list;
}
#PersistenceCapable(detachable = "true")
public class ChildClass {
#Persistent
private ParentClass parent;
}
and then to do the fetching:
PersistenceManager pm = PMF.get("eventual-reads-shortdeadlines").getPersistenceManager();
pm.setDetachAllOnCommit(true);
pm.getFetchPlan().addGroup("fooGroup");
Transaction tx = pm.currentTransaction();
try {
tx.begin();
Query query = pm.newQuery(ParentClass.class);
list = (List<ParentClass>) query.execute();
tx.commit();
} catch (Exception ex) {
...
} finally {
if (pm != null) {
if(pm.currentTransaction().isActive()){
pm.currentTransaction().rollback();
}
pm.close();
}
}
Your ParentClass's should now have all the ChildClass's for each. Hope that helps!