DiscriminatorType.java

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.persister.entity;

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Map;

import org.hibernate.EntityMode;
import org.hibernate.HibernateException;
import org.hibernate.MappingException;
import org.hibernate.engine.jdbc.Size;
import org.hibernate.engine.spi.Mapping;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.engine.spi.SharedSessionContractImplementor;
import org.hibernate.internal.util.collections.ArrayHelper;
import org.hibernate.internal.util.compare.EqualsHelper;
import org.hibernate.type.AbstractType;
import org.hibernate.type.Type;

/**
 * TODO : javadoc
 *
 * @author Steve Ebersole
 */
public class DiscriminatorType extends AbstractType {
	private final Type underlyingType;
	private final Loadable persister;

	public DiscriminatorType(Type underlyingType, Loadable persister) {
		this.underlyingType = underlyingType;
		this.persister = persister;
	}

	public Class getReturnedClass() {
		return Class.class;
	}

	public String getName() {
		return getClass().getName();
	}

	public boolean isMutable() {
		return false;
	}

	public Object nullSafeGet(
			ResultSet rs,
			String[] names,
			SharedSessionContractImplementor session,
			Object owner) throws HibernateException, SQLException {
		return nullSafeGet( rs, names[0], session, owner );
	}

	public Object nullSafeGet(
			ResultSet rs,
			String name,
			SharedSessionContractImplementor session,
			Object owner) throws HibernateException, SQLException {
		final Object discriminatorValue = underlyingType.nullSafeGet( rs, name, session, owner );
		final String entityName = persister.getSubclassForDiscriminatorValue( discriminatorValue );
		if ( entityName == null ) {
			throw new HibernateException( "Unable to resolve discriminator value [" + discriminatorValue + "] to entity name" );
		}
		final EntityPersister entityPersister = session.getEntityPersister( entityName, null );
		return ( EntityMode.POJO == entityPersister.getEntityMode() ) ? entityPersister.getMappedClass() : entityName;
	}

	public void nullSafeSet(
			PreparedStatement st,
			Object value,
			int index,
			boolean[] settable,
			SharedSessionContractImplementor session) throws HibernateException, SQLException {
		nullSafeSet( st, value, index, session );
	}

	public void nullSafeSet(
			PreparedStatement st,
			Object value,
			int index,
			SharedSessionContractImplementor session) throws HibernateException, SQLException {
		String entityName = session.getFactory().getClassMetadata((Class) value).getEntityName();
		Loadable entityPersister = (Loadable) session.getFactory().getEntityPersister(entityName);
		underlyingType.nullSafeSet(st, entityPersister.getDiscriminatorValue(), index, session);
	}

	public String toLoggableString(Object value, SessionFactoryImplementor factory) throws HibernateException {
		return value == null ? "[null]" : value.toString();
	}

	public Object deepCopy(Object value, SessionFactoryImplementor factory)
			throws HibernateException {
		return value;
	}

	public Object replace(Object original, Object target, SharedSessionContractImplementor session, Object owner, Map copyCache)
			throws HibernateException {
		return original;
	}

	public boolean[] toColumnNullness(Object value, Mapping mapping) {
		return value == null
				? ArrayHelper.FALSE
				: ArrayHelper.TRUE;
	}

	public boolean isDirty(Object old, Object current, boolean[] checkable, SharedSessionContractImplementor session)
			throws HibernateException {
		return EqualsHelper.equals( old, current );
	}


	// simple delegation ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

	public int[] sqlTypes(Mapping mapping) throws MappingException {
		return underlyingType.sqlTypes( mapping );
	}

	@Override
	public Size[] dictatedSizes(Mapping mapping) throws MappingException {
		return underlyingType.dictatedSizes( mapping );
	}

	@Override
	public Size[] defaultSizes(Mapping mapping) throws MappingException {
		return underlyingType.defaultSizes( mapping );
	}

	public int getColumnSpan(Mapping mapping) throws MappingException {
		return underlyingType.getColumnSpan( mapping );
	}
}