Hibernate example source code file (IdentifierValue.java)

This example Hibernate source code file (IdentifierValue.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Hibernate tags/keywords

any, boolean, id, identifiervalue, identifiervalue, io, none, null, override, override, serializable, serializable, string, string, undefined

The Hibernate IdentifierValue.java source code

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008-2011, Red Hat Inc. or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.hibernate.engine.spi;

import java.io.Serializable;

import org.jboss.logging.Logger;

import org.hibernate.internal.CoreMessageLogger;

/**
 * A strategy for determining if an identifier value is an identifier of
 * a new transient instance or a previously persistent transient instance.
 * The strategy is determined by the <tt>unsaved-value attribute in
 * the mapping file.
 *
 * @author Gavin King
 */
public class IdentifierValue implements UnsavedValueStrategy {

    private static final CoreMessageLogger LOG = Logger.getMessageLogger(CoreMessageLogger.class, IdentifierValue.class.getName());

	private final Serializable value;

	/**
	 * Always assume the transient instance is newly instantiated
	 */
	public static final IdentifierValue ANY = new IdentifierValue() {
		@Override
        public final Boolean isUnsaved(Object id) {
            LOG.trace("ID unsaved-value strategy ANY");
			return Boolean.TRUE;
		}
		@Override
        public Serializable getDefaultValue(Object currentValue) {
			return (Serializable) currentValue;
		}
		@Override
        public String toString() {
			return "SAVE_ANY";
		}
	};

	/**
	 * Never assume the transient instance is newly instantiated
	 */
	public static final IdentifierValue NONE = new IdentifierValue() {
		@Override
        public final Boolean isUnsaved(Object id) {
            LOG.trace("ID unsaved-value strategy NONE");
			return Boolean.FALSE;
		}
		@Override
        public Serializable getDefaultValue(Object currentValue) {
			return (Serializable) currentValue;
		}
		@Override
        public String toString() {
			return "SAVE_NONE";
		}
	};

	/**
	 * Assume the transient instance is newly instantiated if the identifier
	 * is null.
	 */
	public static final IdentifierValue NULL = new IdentifierValue() {
		@Override
        public final Boolean isUnsaved(Object id) {
            LOG.trace("ID unsaved-value strategy NULL");
			return id==null;
		}
		@Override
        public Serializable getDefaultValue(Object currentValue) {
			return null;
		}
		@Override
        public String toString() {
			return "SAVE_NULL";
		}
	};

	/**
	 * Assume nothing.
	 */
	public static final IdentifierValue UNDEFINED = new IdentifierValue() {
		@Override
        public final Boolean isUnsaved(Object id) {
            LOG.trace("ID unsaved-value strategy UNDEFINED");
			return null;
		}
		@Override
        public Serializable getDefaultValue(Object currentValue) {
			return null;
		}
		@Override
        public String toString() {
			return "UNDEFINED";
		}
	};

	protected IdentifierValue() {
		this.value = null;
	}

	/**
	 * Assume the transient instance is newly instantiated if
	 * its identifier is null or equal to <tt>value
	 */
	public IdentifierValue(Serializable value) {
		this.value = value;
	}

	/**
	 * Does the given identifier belong to a new instance?
	 */
	public Boolean isUnsaved(Object id) {
        LOG.trace("ID unsaved-value: " + value);
		return id==null || id.equals(value);
	}

	public Serializable getDefaultValue(Object currentValue) {
		return value;
	}

	@Override
    public String toString() {
		return "identifier unsaved-value: " + value;
	}
}