* the key to check
* @return true if the key is valid otherwise false
*/
private void checkKey(String key) throws PropertyTypeException {
if (key == null || key.length() == 0) {
throw new PropertyTypeException( "Key must not be null" );
}
String[] keyParts = splitKey( key );
if (keyParts == null) {
throw new PropertyTypeException( "Key must be a QName in the form prefix:localName" );
}
if (registry.getNamespaceURI( keyParts[0] ) == null) {
throw new PropertyTypeException( "Key does not use a registered Namespace prefix" );
}
}