Hi,
I tried to create an object child relationship, both (object and child) are
getting saved properly but while retrieving them back I am getting
nullPointerException for child. Please help, following is my code:
@PersistenceCapable(identityType = IdentityType.APPLICATION)
public class Data{
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
Long id;
@Persistent
MyData mydata;
}
@PersistenceCapable(identityType = IdentityType.APPLICATION)
public class MyData{
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private Key key;
@Persistent(defaultFetchGroup = "true")
String myValue;
}
public class Main extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse resp)
throws IOException{
/*
Data data = new Data();
data.mydata = new MyData();
data.mydata.myValue = "some value";
PersistenceManager pm = PMF.get().getPersistenceManager();
pm.makePersistent(data);
resp.getWriter().print("Done");
*/
PersistenceManager pm = PMF.get().getPersistenceManager();
Data data = pm.getObjectById(Data.class, 3);
resp.getWriter().print(data.mydata.myValue); //
NullPointerException
pm.close();
}
}
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