com.acme.model.AbstractPersistable.java Source code

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Here is the source code for com.acme.model.AbstractPersistable.java

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/*
 * Copyright 2008-2011 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.acme.model;

import java.io.Serializable;

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

import org.springframework.data.domain.Persistable;

/**
 * Abstract base class for entities. Allows parameterization of id type, chooses auto-generation and implements
 * {@link #equals(Object)} and {@link #hashCode()} based on that id.
 * 
 * @author Oliver Gierke
 * @param <PK> the the of the entity
 */
@MappedSuperclass
public abstract class AbstractPersistable<PK extends Serializable> implements Persistable<PK> {

    private static final long serialVersionUID = -5554308939380869754L;

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "id_key_gen")
    @SequenceGenerator(name = "id_key_gen", sequenceName = "id_key_seq", allocationSize = 1)
    protected PK id;
    @Version
    private Integer version;

    /*
     * (non-Javadoc)
     * 
     * @see org.springframework.data.domain.Persistable#getId()
     */
    public PK getId() {

        return id;
    }

    /**
     * Sets the id of the entity.
     * 
     * @param id the id to set
     */
    public void setId(final PK id) {

        this.id = id;
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.springframework.data.domain.Persistable#isNew()
     */
    public boolean isNew() {

        return null == getId();
    }

    /*
     * (non-Javadoc)
     * 
     * @see java.lang.Object#toString()
     */
    @Override
    public String toString() {

        return String.format("Entity of type %s with id: %s", this.getClass().getName(), getId());
    }

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

        if (null == obj) {
            return false;
        }

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

        if (!getClass().equals(obj.getClass())) {
            return false;
        }

        AbstractPersistable<?> that = (AbstractPersistable<?>) obj;

        return null == this.getId() ? false : this.getId().equals(that.getId());
    }

    /*
     * (non-Javadoc)
     * 
     * @see java.lang.Object#hashCode()
     */
    @Override
    public int hashCode() {

        int hashCode = 17;

        hashCode += null == getId() ? 0 : getId().hashCode() * 31;

        return hashCode;
    }

    public Integer getVersion() {
        return version;
    }

    public void setVersion(Integer version) {
        this.version = version;
    }
}