BigDecimalHelper.java

/*
 * BigDecimalHelper.java
 * Copyright 2003 (C) Jonas Karlsson <jujutsunerd@sf.net>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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 library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Created on April 12, 2003, 3:20 AM
 */
package pcgen.util;

import java.math.BigDecimal;

/**
 * This contains helper functions for BigDecimal.
 * @author     Jonas Karlsson <jujutsunerd@sf.net>
 */
public class BigDecimalHelper
{

	/**
	 * trimBigDecimal ( (BigDecimal) a) to cut off all trailing zeros.
	 * It's a terrible hack.
	 * @param n the BigDecimal to trim all trailing zeros from
	 * @return the trimmed BigDecimal
	 */
	public static BigDecimal trimBigDecimal(BigDecimal n)
	{
		if (n.unscaledValue().intValue() == 0)
		{
			// Java 1.5 will not throw an ArthmeticException if you change the
			// scale of 0.0 to 0, so it will keep going through the loop below
			// forever. To get around this we test for the special case here.
			return BigDecimal.ZERO;
		}

		if (n.scale() <= 0)
		{
			return n;
		}

		BigDecimal stripped = n.stripTrailingZeros();
		if (stripped.scale() < 0)
		{
			stripped = n.setScale(0);
		}

		return stripped;
	}

	/**
	 * Returns a string with the trimmed number.
	 * E.g. {@literal numberToTrim=3.1000 > 3.1 }
	 * If numberToTrim is non-numeric, 0 is returned (should be changed.)
	 * @param numberToTrim The value to trim.
	 * @return String
	 */
	public static String trimZeros(String numberToTrim)
	{
		BigDecimal aBigD = BigDecimal.ZERO;

		try
		{
			aBigD = new BigDecimal(numberToTrim);
		}
		catch (NumberFormatException exc)
		{
			Logging.errorPrint("Cannot trim zeroes from " + numberToTrim
				+ " as is not a number. Using 0 instead.");
		}

		return trimBigDecimal(aBigD).toString();
	}

	/**
	 * Trims the zeros. 
	 * @param n bigdecimal to trim
	 * @return String without zeros
	 */
	public static String trimZeros(BigDecimal n)
	{
		return trimBigDecimal(n).toString();
	}
}