| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.apache.tinkerpop.gremlin.structure.util; |
| |
| import org.apache.tinkerpop.gremlin.structure.Edge; |
| import org.apache.tinkerpop.gremlin.structure.Property; |
| import org.apache.tinkerpop.gremlin.structure.Vertex; |
| |
| /** |
| * A marker interface that identifies an object as something that an {@link Attachable} can connect to. |
| * |
| * @author Stephen Mallette (http://stephen.genoprime.com) |
| */ |
| public interface Host { |
| |
| /** |
| * Extracts the {@link Vertex} that is holding the specified object. |
| * |
| * @throws IllegalStateException if the object is not a graph element type |
| */ |
| public static Vertex getHostingVertex(final Object object) { |
| Object obj = object; |
| while (true) { |
| if (obj instanceof Vertex) |
| return (Vertex) obj; |
| else if (obj instanceof Edge) |
| return ((Edge) obj).outVertex(); |
| else if (obj instanceof Property) |
| obj = ((Property) obj).element(); |
| else |
| throw new IllegalStateException("The host of the object is unknown: " + obj.toString() + ':' + obj.getClass().getCanonicalName()); |
| } |
| } |
| } |