currency.java

老外的在线考试

/*
 * Core - Library of useful classes that are used in many CyberDemia projects.
 * Copyright (C) 2003 CyberDemia Research and Services
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 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
 * Library General Public License for more details.
 * 
 * You should have received a copy of the GNU Library 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.
 *
 * See the COPYING file located in the top-level-directory of
 * the archive of this library for complete text of license.
 */
package com.cyberdemia.value;
import com.cyberdemia.util.Format;

/**
* <p>
* Currency encapsulates a currency/money value.
* This can be treated as a simple Javabean,
* with a double property named <i>value</i>.
* </p>
* <p>
* Note: In the default English-US locale, a value of
* 1.0 represents $1.00.
* </p>
* <p>
* The formatting to a String is locale dependent,
* hence this class depends on <code>com.cyberdemia.util.Format</code>
* to perform formatting and manage locale.
* </p>
*
* @author  Alexander Yap
* @see com.cyberdemia.util.Format
* @version $Revision: 1.2 $ at $Date: 2004/02/18 08:35:30 $ by $Author: alexycyap $
*/
public class Currency extends DoubleType
{
	/**
	* Default constructor
	*/
	public Currency()
	{
		super();
	}

	/**
	* Convenient constructor.
	*/
	public Currency( double val)
	{
		super(val);
	}

	/**
	* <p>
	* Gets value as a String, using default settings and current locale as
	* set in <code>com.cyberdemia.util.Format</code>.
	* </p>
	* <p><b>Note:</b>The <code>toString()</code> method calls this method.
	* </p>
	*
	*
	* @return Currency string for the current locale.
	* @see com.cyberdemia.util.Format#formatCurrency( double )
	*/
	public String getStringValue()
	{
		return Format.formatCurrency( getValue() );
	}

	/**
	* Converts to a String, using current locale as set in
	* <code>com.cyberdemia.util.Format</code>.
	* The number of fractional digits can be specified.
	* Grouping can be enabled or disabled.
	*
	* @param    minFracDigits  minimum number of fractional digits
	* @param    maxFracDigits  maximum number of fractional digits
	* @param    grouped        enable or disable grouping
	* @return Currency string for the current locale.
	* @see com.cyberdemia.util.Format#formatCurrency( double, int, int, boolean )
	*/
	public String toString(int minFracDigits, int maxFracDigits, boolean grouped)
	{
		return Format.formatCurrency( getValue(), minFracDigits, maxFracDigits, grouped);
	}

	/**
	* Creates a clone of this Currency object.
	* @return  Clone of this object.
	*/
	public Object clone()
	{
		return new Currency( getValue() );
	}

	/**
	* Returns true if this currency can be treated as 0.
	* Currency need not require a high level of precision.
	* So if the absolute value is less than 0.0001, it is treated as 0.
	*/
	public boolean isZero()
	{
		return (Math.abs( getValue() )<0.0001); 
	}
}