AbstractEntity.java

/*
 * Copyright 2012 the original author or authors.
 *
 * Licensed 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 com.oreilly.springdata.jpa.core;

import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.MappedSuperclass;

/**
 * Base class to derive entity classes from.
 * 
 * @author Oliver Gierke
 */
@MappedSuperclass
public class AbstractEntity {

	@Id
	@GeneratedValue(strategy = GenerationType.AUTO)
	private Long id;

	/**
	 * Returns the identifier of the entity.
	 * 
	 * @return the id
	 */
	public Long getId() {
		return id;
	}

	/* 
	 * (non-Javadoc)
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	@Override
	public boolean equals(Object obj) {

		if (this == obj) {
			return true;
		}

		if (this.id == null || obj == null || !(this.getClass().equals(obj.getClass()))) {
			return false;
		}

		AbstractEntity that = (AbstractEntity) obj;

		return this.id.equals(that.getId());
	}

	/* 
	 * (non-Javadoc)
	 * @see java.lang.Object#hashCode()
	 */
	@Override
	public int hashCode() {
		return id == null ? 0 : id.hashCode();
	}
}