/**
* 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;
}
/**
* 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;
}
}
