001 /**
002 * =========================================
003 * LibFormula : a free Java formula library
004 * =========================================
005 *
006 * Project Info: http://reporting.pentaho.org/libformula/
007 *
008 * (C) Copyright 2006-2007, by Pentaho Corporation and Contributors.
009 *
010 * This library is free software; you can redistribute it and/or modify it under the terms
011 * of the GNU Lesser General Public License as published by the Free Software Foundation;
012 * either version 2.1 of the License, or (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
015 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
016 * See the GNU Lesser General Public License for more details.
017 *
018 * You should have received a copy of the GNU Lesser General Public License along with this
019 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
020 * Boston, MA 02111-1307, USA.
021 *
022 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
023 * in the United States and other countries.]
024 *
025 *
026 * ------------
027 * $Id: DivideOperator.java 2887 2007-06-06 17:07:52Z taqua $
028 * ------------
029 * (C) Copyright 2006-2007, by Pentaho Corporation.
030 */
031 package org.jfree.formula.operators;
032
033 import java.math.BigDecimal;
034
035 import org.jfree.formula.EvaluationException;
036 import org.jfree.formula.LibFormulaErrorValue;
037 import org.jfree.formula.util.NumberUtil;
038 import org.jfree.util.Log;
039
040 /**
041 * A division operation. This operation expects two valid numbers.
042 *
043 *
044 * @author Thomas Morgner
045 */
046 public class DivideOperator extends AbstractNumericOperator
047 {
048 public DivideOperator()
049 {
050 }
051
052 public Number evaluate(final Number number1, final Number number2) throws EvaluationException
053 {
054 final BigDecimal bd1 = new BigDecimal(number1.toString());
055 final BigDecimal bd2 = new BigDecimal(number2.toString());
056 if (bd2.signum() == 0)
057 {
058 // prevent a division by zero ..
059 Log.debug ("Preventing a Division by Zero: " + number2);
060 throw new EvaluationException(LibFormulaErrorValue.ERROR_ARITHMETIC_VALUE);
061 }
062 final BigDecimal divide = bd1.divide(bd2, 40, BigDecimal.ROUND_HALF_UP);
063 return NumberUtil.removeTrailingZeros(divide);
064 }
065
066 public int getLevel()
067 {
068 return 100;
069 }
070
071
072 public String toString()
073 {
074 return "/";
075 }
076
077 public boolean isLeftOperation()
078 {
079 return true;
080 }
081
082 /**
083 * Defines, whether the operation is associative. For associative operations,
084 * the evaluation order does not matter, if the operation appears more than
085 * once in an expression, and therefore we can optimize them a lot better than
086 * non-associative operations (ie. merge constant parts and precompute them
087 * once).
088 *
089 * @return true, if the operation is associative, false otherwise
090 */
091 public boolean isAssociative()
092 {
093 return false;
094 }
095
096 }