org.springframework.data.jpa.domain.AbstractPersistable.java Source code

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Here is the source code for org.springframework.data.jpa.domain.AbstractPersistable.java

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/*
 * Copyright 2008-2019 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
 *
 *      https://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.springframework.data.jpa.domain;

import java.io.Serializable;

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

import org.springframework.data.domain.Persistable;
import org.springframework.data.util.ProxyUtils;
import org.springframework.lang.Nullable;

/**
 * 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
 * @author Thomas Darimont
 * @author Mark Paluch
 * @param <PK> the type of the identifier.
 */
@MappedSuperclass
public abstract class AbstractPersistable<PK extends Serializable> implements Persistable<PK> {

    private static final long serialVersionUID = -5554308939380869754L;

    @Id
    @GeneratedValue
    private @Nullable PK id;

    /*
     * (non-Javadoc)
     * @see org.springframework.data.domain.Persistable#getId()
     */
    @Nullable
    @Override
    public PK getId() {
        return id;
    }

    /**
     * Sets the id of the entity.
     *
     * @param id the id to set
     */
    protected void setId(@Nullable PK id) {
        this.id = id;
    }

    /**
     * Must be {@link Transient} in order to ensure that no JPA provider complains because of a missing setter.
     *
     * @see org.springframework.data.domain.Persistable#isNew()
     */
    @Transient // DATAJPA-622
    @Override
    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(ProxyUtils.getUserClass(obj))) {
            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;
    }
}