How to use

selectOneObject

method

in

org.eclipse.persistence.descriptors.InterfacePolicy

  /**
   * INTERNAL:
   * Select one object of any concrete subclass.
   */
  @Override
  protected Object selectOneObject(ReadObjectQuery query) throws DescriptorException {
    if (this.descriptor.isAbstract()) {
      return null;
    }
    return super.selectOneObject(query);
  }
}

  /**
   * INTERNAL:
   * Select one object of any concrete subclass.
   */
  @Override
  protected Object selectOneObject(ReadObjectQuery query) throws DescriptorException {
    if (this.descriptor.isAbstract()) {
      return null;
    }
    return super.selectOneObject(query);
  }
}

/**
 * INTERNAL:
 * Select one object of any concrete subclass.
 */
public Object selectOneObjectUsingMultipleTableSubclassRead(ReadObjectQuery query) throws DatabaseException, QueryException {
  int size = this.childDescriptors.size();
  for (int index = 0; index < size; index++) {
    ClassDescriptor descriptor = this.childDescriptors.get(index);
    Object object = descriptor.getInterfacePolicy().selectOneObject(query);
    if (object != null) {
      return object;
    }
  }
  return null;
}

/**
 * INTERNAL:
 * Select one object of any concrete subclass.
 */
public Object selectOneObjectUsingMultipleTableSubclassRead(ReadObjectQuery query) throws DatabaseException, QueryException {
  int size = this.childDescriptors.size();
  for (int index = 0; index < size; index++) {
    ClassDescriptor descriptor = this.childDescriptors.get(index);
    Object object = descriptor.getInterfacePolicy().selectOneObject(query);
    if (object != null) {
      return object;
    }
  }
  return null;
}

/**
 * INTERNAL:
 * Select one object of any concrete subclass.
 */
public Object selectOneObjectUsingMultipleTableSubclassRead(ReadObjectQuery query) throws DatabaseException, QueryException {
  Object object = null;
  for (Enumeration childDescriptors = getChildDescriptors().elements(); childDescriptors.hasMoreElements() && (object == null);) {
    ClassDescriptor descriptor = (ClassDescriptor)childDescriptors.nextElement();
    object = descriptor.getInterfacePolicy().selectOneObject(query);
  }
  return object;
}