Пример #1
0
  /**
   * Instantiates a new object and registers it with this context. Object class is determined from
   * the mapped entity. Object class must have a default constructor.
   *
   * <p><i>Note: in most cases {@link #newObject(Class)} method should be used, however this method
   * is helpful when generic persistent classes are used.</i>
   *
   * @since 3.0
   */
  public Persistent newObject(String entityName) {
    ClassDescriptor descriptor = getEntityResolver().getClassDescriptor(entityName);
    if (descriptor == null) {
      throw new IllegalArgumentException("Invalid entity name: " + entityName);
    }

    Persistent object;
    try {
      object = (Persistent) descriptor.createObject();
    } catch (Exception ex) {
      throw new CayenneRuntimeException("Error instantiating object.", ex);
    }

    // this will initialize to-many lists
    descriptor.injectValueHolders(object);

    ObjectId id = new ObjectId(entityName);

    // note that the order of initialization of persistence artifacts below
    // is
    // important - do not change it lightly
    object.setObjectId(id);

    injectInitialValue(object);

    return object;
  }
Пример #2
0
  /**
   * An internal version of {@link #localObject(Object)} that operates on ObjectId instead of
   * Persistent, and wouldn't attempt to look up an object in the parent channel.
   *
   * @since 3.1
   */
  Persistent findOrCreateObject(ObjectId id) {

    if (id == null) {
      throw new IllegalArgumentException("Null ObjectId");
    }

    // have to synchronize almost the entire method to prevent multiple
    // threads from
    // messing up dataobjects per CAY-845. Originally only parts of "else"
    // were
    // synchronized, but we had to expand the lock scope to ensure
    // consistent
    // behavior.
    synchronized (getGraphManager()) {
      Persistent cachedObject = (Persistent) getGraphManager().getNode(id);

      // return an existing object
      if (cachedObject != null) {

        int state = cachedObject.getPersistenceState();

        // TODO: Andrus, 1/24/2006 implement smart merge for modified
        // objects...
        if (state != PersistenceState.MODIFIED && state != PersistenceState.DELETED) {

          ClassDescriptor descriptor = getEntityResolver().getClassDescriptor(id.getEntityName());

          descriptor.injectValueHolders(cachedObject);
        }

        return cachedObject;
      }

      // create and register a hollow object
      ClassDescriptor descriptor = getEntityResolver().getClassDescriptor(id.getEntityName());
      Persistent localObject = (Persistent) descriptor.createObject();

      localObject.setObjectContext(this);
      localObject.setObjectId(id);

      getGraphManager().registerNode(id, localObject);
      localObject.setPersistenceState(PersistenceState.HOLLOW);

      return localObject;
    }
  }