/*
* 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.openjpa.persistence.graph;
import java.io.Serializable;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.MappedSuperclass;
/**
* Persistent Graph is a marker for persistent version of a {@link Graph}.
* <br>
* A persistent graph does not declare how the persistent state of the graph is captured and hence is abstract.
* But Persistent Graph is unique to be persistent in a JPA sense, because JPA does <em>not</em> represent
* container instances such as {@link java.util.Set} or {@link java.util.List} as <em>first class</em> type --
* i.e. their instances do not carry a persistent identity. But declaring a graph as persistent type amounts
* to represent the graph as a first class persistent type with its own persistent identity.
* <br>
* Persistent Graph defines a auto-generated persistent identity.
*
* @author Pinaki Poddar
*
* @param <E> type of element.
*/
@SuppressWarnings("serial")
@MappedSuperclass
public abstract class PersistentGraph<E> extends AbstractGraph<E> implements Serializable {
@Id
@GeneratedValue
private long id;
public final long getId() {
return id;
}
}