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    }