| /* |
| * 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; |
| |
| import org.apache.tinkerpop.gremlin.structure.util.empty.EmptyVertexProperty; |
| |
| import java.util.Iterator; |
| |
| /** |
| * A {@code VertexProperty} is similar to a {@link Property} in that it denotes a key/value pair associated with an |
| * {@link Vertex}, however it is different in the sense that it also represents an entity that it is an {@link Element} |
| * that can have properties of its own. |
| * <p/> |
| * A property is much like a Java8 {@code Optional} in that a property can be not present (i.e. empty). |
| * The key of a property is always a String and the value of a property is an arbitrary Java object. |
| * Each underlying graph engine will typically have constraints on what Java objects are allowed to be used as values. |
| * |
| * @author Matthias Broecheler (me@matthiasb.com) |
| * @author Marko A. Rodriguez (http://markorodriguez.com) |
| * @author Stephen Mallette (http://stephen.genoprime.com) |
| */ |
| public interface VertexProperty<V> extends Property<V>, Element { |
| |
| public static final String DEFAULT_LABEL = "vertexProperty"; |
| |
| public enum Cardinality { |
| single, list, set |
| } |
| |
| /** |
| * Gets the {@link Vertex} that owns this {@code VertexProperty}. |
| */ |
| @Override |
| public Vertex element(); |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public default Graph graph() { |
| return this.element().graph(); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public default String label() { |
| return this.key(); |
| } |
| |
| /** |
| * Constructs an empty {@code VertexProperty}. |
| */ |
| public static <V> VertexProperty<V> empty() { |
| return EmptyVertexProperty.instance(); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public <U> Iterator<Property<U>> properties(final String... propertyKeys); |
| |
| |
| /** |
| * Common exceptions to use with a property. |
| */ |
| public static class Exceptions { |
| |
| private Exceptions() { |
| } |
| |
| public static UnsupportedOperationException userSuppliedIdsNotSupported() { |
| return new UnsupportedOperationException("VertexProperty does not support user supplied identifiers"); |
| } |
| |
| public static UnsupportedOperationException userSuppliedIdsOfThisTypeNotSupported() { |
| return new UnsupportedOperationException("VertexProperty does not support user supplied identifiers of this type"); |
| } |
| |
| public static UnsupportedOperationException multiPropertiesNotSupported() { |
| return new UnsupportedOperationException("Multiple properties on a vertex is not supported"); |
| } |
| |
| public static UnsupportedOperationException identicalMultiPropertiesNotSupported() { |
| return new UnsupportedOperationException("Multiple properties on a vertex is supported, but a single key may not hold the same value more than once"); |
| } |
| |
| public static UnsupportedOperationException metaPropertiesNotSupported() { |
| return new UnsupportedOperationException("Properties on a vertex property is not supported"); |
| } |
| } |
| } |