UnsignedByteType.java

/*
 * @(#)$Id: UnsignedByteType.java,v 1.15 2001/08/14 22:17:58 Bear Exp $
 *
 * Copyright 2001 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * This software is the proprietary information of Sun Microsystems, Inc.  
 * Use is subject to license terms.
 * 
 */
package com.sun.msv.datatype.xsd;

import org.relaxng.datatype.ValidationContext;

/**
 * "unsignedByte" type.
 * 
 * type of the value object is <code>java.lang.Short</code>.
 * See http://www.w3.org/TR/xmlschema-2/#unsignedByte for the spec
 * 
 * @author <a href="mailto:kohsuke.kawaguchi@eng.sun.com">Kohsuke KAWAGUCHI</a>
 */
public class UnsignedByteType extends ShortType {
	public static final UnsignedByteType theInstance = new UnsignedByteType();
	private UnsignedByteType() { super("unsignedByte"); }

    /** upper bound value. this is the maximum possible valid value as an unsigned int */
    private static final short upperBound = 255;
	
	final public XSDatatype getBaseType() {
		return UnsignedShortType.theInstance;
	}

	public Object _createValue( String lexicalValue, ValidationContext context ) {
		// Implementation of JDK1.2.2/JDK1.3 is suitable enough
		try {
			Short v = (Short)super._createValue(lexicalValue,context);
			if( v==null )						return null;
			if( v.shortValue()<0 )               return null;
			if( v.shortValue()>upperBound )      return null;
			return v;
		} catch( NumberFormatException e ) {
			return null;
		}
	}
}