Hibernate example source code file (StringTypeDescriptor.java)

This example Hibernate source code file (StringTypeDescriptor.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

abstracttypedescriptor, class, clob, hibernateexception, io, jdbc, reader, sql, string, string, stringreader, stringtypedescriptor, stringtypedescriptor, wrapperoptions, wrapperoptions, x, x

The Hibernate StringTypeDescriptor.java source code

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2010, 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.type.descriptor.java;

import java.io.Reader;
import java.io.StringReader;
import java.sql.Clob;
import java.sql.SQLException;

import org.hibernate.HibernateException;
import org.hibernate.type.descriptor.CharacterStream;
import org.hibernate.type.descriptor.WrapperOptions;

/**
 * Descriptor for {@link String} handling.
 *
 * @author Steve Ebersole
 */
public class StringTypeDescriptor extends AbstractTypeDescriptor<String> {
	public static final StringTypeDescriptor INSTANCE = new StringTypeDescriptor();

	public StringTypeDescriptor() {
		super( String.class );
	}

	public String toString(String value) {
		return value;
	}

	public String fromString(String string) {
		return string;
	}

	@SuppressWarnings({ "unchecked" })
	public <X> X unwrap(String value, Class type, WrapperOptions options) {
		if ( value == null ) {
			return null;
		}
		if ( String.class.isAssignableFrom( type ) ) {
			return (X) value;
		}
		if ( Reader.class.isAssignableFrom( type ) ) {
			return (X) new StringReader( value );
		}
		if ( CharacterStream.class.isAssignableFrom( type ) ) {
			return (X) new CharacterStreamImpl( value );
		}
		if ( Clob.class.isAssignableFrom( type ) ) {
			return (X) options.getLobCreator().createClob( value );
		}
		if ( DataHelper.isNClob( type ) ) {
			return (X) options.getLobCreator().createNClob( value );
		}

		throw unknownUnwrap( type );
	}

	public <X> String wrap(X value, WrapperOptions options) {
		if ( value == null ) {
			return null;
		}
		if ( String.class.isInstance( value ) ) {
			return (String) value;
		}
		if ( Reader.class.isInstance( value ) ) {
			return DataHelper.extractString( (Reader) value );
		}
		if ( Clob.class.isInstance( value ) || DataHelper.isNClob( value.getClass() ) ) {
			try {
				return DataHelper.extractString( ( (Clob) value ).getCharacterStream() );
			}
			catch ( SQLException e ) {
				throw new HibernateException( "Unable to access lob stream", e );
			}
		}

		throw unknownWrap( value.getClass() );
	}
}