NumberType.java

/*
 * @(#)$Id: NumberType.java,v 1.19 2002/10/08 22:01:27 kk122374 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 java.math.BigDecimal;
import java.math.BigInteger;
import org.relaxng.datatype.ValidationContext;
import com.sun.msv.datatype.SerializationContext;

/**
 * "decimal" type.
 * 
 * type of the value object is <code>java.math.BigDecimal</code>.
 * See http://www.w3.org/TR/xmlschema-2/#decimal for the spec.
 * It was once known as "number" type.
 * 
 * @author <a href="mailto:kohsuke.kawaguchi@eng.sun.com">Kohsuke KAWAGUCHI</a>
 */
public class NumberType extends BuiltinAtomicType implements Comparator {
	public static final NumberType theInstance = new NumberType();
	private NumberType() { super("decimal"); }
	
	final public XSDatatype getBaseType() {
		return SimpleURType.theInstance;
	}
	
	/** constant */
	private static final BigInteger the10 = new BigInteger("10");

	protected boolean checkFormat( String content, ValidationContext context ) {
		final int len = content.length();
		int i=0;
		char ch;
		boolean atLeastOneDigit = false;
		
		if(len==0)	return false;		// length 0 is not allowed
		
		// leading optional sign
		ch = content.charAt(0);
		if(ch=='-' || ch=='+')	i++;
		
		while(i<len) {
			ch = content.charAt(i++);
			if('0'<=ch && ch<='9') {
				atLeastOneDigit = true;
				continue;
			}
			if(ch=='.')	break;
			return false;		// other characters are error
		}
		
		while(i<len) {
			// fractional part
			ch = content.charAt(i++);
			if('0'<=ch && ch<='9') {
				atLeastOneDigit = true;
				continue;
			}
			return false;	// other characters are error
		}
		
		return atLeastOneDigit;	// at least one digit must be present.
	}
	
	public Object _createValue( String content, ValidationContext context ) {
		// BigDecimal accepts expressions like "1E4",
		// but XML Schema doesn't.
			
		// so call checkFormat to make sure that
		// format is XML Schema spec compliant.
		if(!checkFormat(content,context))		return null;

        return load(content);
    }
    
    public static BigDecimal load( String content ) {
		try	{
			// XML Schema allows optional leading '+' sign,
			// but BigDecimal doesn't.
			// so remove it here.
			
			if( content.length()==0 )		return null;
			
			if( content.charAt(0)=='+' )
				content = content.substring(1);
			
			BigDecimal r = new BigDecimal(content);
			
			// BigDecimal treats 0 != 0.0
			// to workaround this, "normalize" BigDecimal;
			// that is, trailing zeros in fractional digits are removed.
			while(r.scale()>0) {
				BigInteger[] q_r = 
					r.unscaledValue().divideAndRemainder(the10);
				
				if( !q_r[1].equals(BigInteger.ZERO) )	break;
				
				r = new BigDecimal(q_r[0], r.scale()-1);
			}
			
			return r;
		} catch( NumberFormatException e ) {
			return null;
		}
	}
    
    public static String save( Object o ) {
        return ((BigDecimal)o).toString();
    }
    
	public Class getJavaObjectType() {
		return BigDecimal.class;
	}
	
	public String convertToLexicalValue( Object o, SerializationContext context ) {
		if(o instanceof BigDecimal)
			return o.toString();
		else
			throw new IllegalArgumentException();
	}

	public final int isFacetApplicable( String facetName ) {
		if( facetName.equals(FACET_TOTALDIGITS)
		||	facetName.equals(FACET_FRACTIONDIGITS)
		||	facetName.equals(FACET_PATTERN)
		||	facetName.equals(FACET_ENUMERATION)
        ||  facetName.equals(FACET_WHITESPACE)
		||	facetName.equals(FACET_MAXINCLUSIVE)
		||	facetName.equals(FACET_MININCLUSIVE)
		||	facetName.equals(FACET_MAXEXCLUSIVE)
		||	facetName.equals(FACET_MINEXCLUSIVE) )
			return APPLICABLE;
		else
			return NOT_ALLOWED;
	}

	public final int compare( Object o1, Object o2 ) {
		final int r = ((Comparable)o1).compareTo(o2);
		if(r<0)	return LESS;
		if(r>0)	return GREATER;
		return EQUAL;
	}
}