Hibernate example source code file (Tools.java)

This example Hibernate source code file (Tools.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

arraylist, class, hibernateproxy, iterator, k,v, list, list, map, object, object, string, string, t, t, util

The Hibernate Tools.java source code

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008, Red Hat Middleware LLC 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 Middleware LLC.
 *
 * 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.envers.tools;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
import javassist.util.proxy.ProxyFactory;
import org.hibernate.Session;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.persister.entity.EntityPersister;
import org.hibernate.proxy.HibernateProxy;

/**
 * @author Adam Warski (adam at warski dot org)
 * @author Hern�n Chanfreau
 * @author Lukasz Antoniak (lukasz dot antoniak at gmail dot com)
 */
public class Tools {
    public static <K,V> Map newHashMap() {
        return new HashMap<K,V>();
    }

    public static <E> Set newHashSet() {
        return new HashSet<E>();
    }

    public static <K,V> Map newLinkedHashMap() {
        return new LinkedHashMap<K,V>();
    }

	public static boolean entitiesEqual(SessionImplementor session, String entityName, Object obj1, Object obj2) {
        Object id1 = getIdentifier(session, entityName, obj1);
		Object id2 = getIdentifier(session, entityName, obj2);

        return objectsEqual(id1, id2);
    }	

	public static Object getIdentifier(SessionImplementor session, String entityName, Object obj) {
		if (obj == null) {
			return null;
		}

		if (obj instanceof HibernateProxy) {
			HibernateProxy hibernateProxy = (HibernateProxy) obj;
			return hibernateProxy.getHibernateLazyInitializer().getIdentifier();
		}

		return session.getEntityPersister(entityName, obj).getIdentifier(obj, session);
	}	    


    public static Object getTargetFromProxy(SessionFactoryImplementor sessionFactoryImplementor, HibernateProxy proxy) {
        if (!proxy.getHibernateLazyInitializer().isUninitialized()) {
            return proxy.getHibernateLazyInitializer().getImplementation();
        }

        SessionImplementor sessionImplementor = proxy.getHibernateLazyInitializer().getSession();
        Session tempSession = sessionImplementor==null
				? sessionFactoryImplementor.openTemporarySession()
				: sessionImplementor.getFactory().openTemporarySession();
        try {
			Object target = tempSession.get(
					proxy.getHibernateLazyInitializer().getEntityName(),
					proxy.getHibernateLazyInitializer().getIdentifier()
			);
			return target;
        }
		finally {
            tempSession.close();
        }
    }

    /**
     * @param clazz Class wrapped with a proxy or not.
     * @param <T> Class type.
     * @return Returns target class in case it has been wrapped with a proxy. If {@code null} reference is passed,
     *         method returns {@code null}. 
     */
    @SuppressWarnings({"unchecked"})
    public static <T> Class getTargetClassIfProxied(Class clazz) {
        if (clazz == null) {
            return null;
        } else if (ProxyFactory.isProxyClass(clazz)) {
            // Get the source class of Javassist proxy instance.
            return (Class<T>) clazz.getSuperclass();
        }
        return clazz;
    }

    public static boolean objectsEqual(Object obj1, Object obj2) {
        if (obj1 == null) {
            return obj2 == null;
        }

        return obj1.equals(obj2);
    }

    public static <T> List iteratorToList(Iterator iter) {
        List<T> ret = new ArrayList();
        while (iter.hasNext()) {
            ret.add(iter.next());
        }

        return ret;
    }

    public static boolean iteratorsContentEqual(Iterator iter1, Iterator iter2) {
        while (iter1.hasNext() && iter2.hasNext()) {
            if (!iter1.next().equals(iter2.next())) {
                return false;
            }
        }

        //noinspection RedundantIfStatement
        if (iter1.hasNext() || iter2.hasNext()) {
            return false;
        }

        return true;
    }

    /**
     * Transforms a list of arbitrary elements to a list of index-element pairs.
     * @param list List to transform.
     * @return A list of pairs: ((0, element_at_index_0), (1, element_at_index_1), ...)
     */
    public static <T> List> listToIndexElementPairList(List list) {
        List<Pair ret = new ArrayList>();
        Iterator<T> listIter = list.iterator();
        for (int i=0; i<list.size(); i++) {
            ret.add(Pair.make(i, listIter.next()));
        }

        return ret;
    }

    /**
     * @param properties Properties from which to read.
     * @param propertyName The name of the property.
     * @param legacyPropertyName Legacy name of the property. The value of this property is read if value for
     * {@code propertyName} is not set.
     * @param defaultValue Default value returned if a value neither for {@code propertyName} or
     * {@code legacyPropertyName} is set.
     * @return The value of the property, legacy proparty or the default value, if neither of the values are not set.
     */
    public static String getProperty(Properties properties, String propertyName, String legacyPropertyName, String defaultValue) {
        String value = properties.getProperty(propertyName, null);
        if (value == null) {
            return properties.getProperty(legacyPropertyName, defaultValue);
        } else {
            return value;
        }
    }

    /**
     * @return Java class mapped to specified entity name.
     */
    public static Class getEntityClass(SessionImplementor sessionImplementor, Session session, String entityName) {
        EntityPersister entityPersister = sessionImplementor.getFactory().getEntityPersister(entityName);
        return entityPersister.getMappedClass();
    }
}