| /* |
| * 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.process.traversal.step.map; |
| |
| import org.apache.tinkerpop.gremlin.process.traversal.Traversal; |
| import org.apache.tinkerpop.gremlin.process.traversal.Traverser; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.Configuring; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.util.Parameters; |
| import org.apache.tinkerpop.gremlin.process.traversal.traverser.TraverserRequirement; |
| import org.apache.tinkerpop.gremlin.structure.Edge; |
| import org.apache.tinkerpop.gremlin.structure.Vertex; |
| import org.apache.tinkerpop.gremlin.structure.util.ElementHelper; |
| |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Set; |
| |
| /** |
| * @author Marko A. Rodriguez (http://markorodriguez.com) |
| */ |
| public class EdgeOtherVertexStep extends MapStep<Edge, Vertex> implements Configuring { |
| protected Parameters parameters = new Parameters(); |
| |
| public EdgeOtherVertexStep(final Traversal.Admin traversal) { |
| super(traversal); |
| } |
| |
| @Override |
| protected Vertex map(final Traverser.Admin<Edge> traverser) { |
| final List<Object> objects = traverser.path().objects(); |
| for (int i = objects.size() - 2; i >= 0; i--) { |
| if (objects.get(i) instanceof Vertex) { |
| return ElementHelper.areEqual((Vertex) objects.get(i), traverser.get().outVertex()) ? |
| traverser.get().inVertex() : |
| traverser.get().outVertex(); |
| } |
| } |
| throw new IllegalStateException("The path history of the traverser does not contain a previous vertex: " + traverser.path()); |
| } |
| |
| @Override |
| public Parameters getParameters() { |
| return this.parameters; |
| } |
| |
| @Override |
| public void configure(final Object... keyValues) { |
| this.parameters.set(null, keyValues); |
| } |
| |
| @Override |
| public Set<TraverserRequirement> getRequirements() { |
| return Collections.singleton(TraverserRequirement.PATH); |
| } |
| } |