Source for org.jfree.formula.operators.DivideOperator

   1: /**
   2:  * =========================================
   3:  * LibFormula : a free Java formula library
   4:  * =========================================
   5:  *
   6:  * Project Info:  http://reporting.pentaho.org/libformula/
   7:  *
   8:  * (C) Copyright 2006-2007, by Pentaho Corporation and Contributors.
   9:  *
  10:  * This library is free software; you can redistribute it and/or modify it under the terms
  11:  * of the GNU Lesser General Public License as published by the Free Software Foundation;
  12:  * either version 2.1 of the License, or (at your option) any later version.
  13:  *
  14:  * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
  15:  * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  16:  * See the GNU Lesser General Public License for more details.
  17:  *
  18:  * You should have received a copy of the GNU Lesser General Public License along with this
  19:  * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  20:  * Boston, MA 02111-1307, USA.
  21:  *
  22:  * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
  23:  * in the United States and other countries.]
  24:  *
  25:  *
  26:  * ------------
  27:  * $Id: DivideOperator.java 2887 2007-06-06 17:07:52Z taqua $
  28:  * ------------
  29:  * (C) Copyright 2006-2007, by Pentaho Corporation.
  30:  */
  31: package org.jfree.formula.operators;
  32: 
  33: import java.math.BigDecimal;
  34: 
  35: import org.jfree.formula.EvaluationException;
  36: import org.jfree.formula.LibFormulaErrorValue;
  37: import org.jfree.formula.util.NumberUtil;
  38: import org.jfree.util.Log;
  39: 
  40: /**
  41:  * A division operation. This operation expects two valid numbers.
  42:  *
  43:  *
  44:  * @author Thomas Morgner
  45:  */
  46: public class DivideOperator extends AbstractNumericOperator
  47: {
  48:   public DivideOperator()
  49:   {
  50:   }
  51: 
  52:   public Number evaluate(final Number number1, final Number number2) throws EvaluationException
  53:   {
  54:     final BigDecimal bd1 = new BigDecimal(number1.toString());
  55:     final BigDecimal bd2 = new BigDecimal(number2.toString());
  56:     if (bd2.signum() == 0)
  57:     {
  58:       // prevent a division by zero ..
  59:       Log.debug ("Preventing a Division by Zero: " + number2);
  60:       throw new EvaluationException(LibFormulaErrorValue.ERROR_ARITHMETIC_VALUE);
  61:     }
  62:     final BigDecimal divide = bd1.divide(bd2, 40, BigDecimal.ROUND_HALF_UP);
  63:     return NumberUtil.removeTrailingZeros(divide);
  64:   }
  65: 
  66:   public int getLevel()
  67:   {
  68:     return 100;
  69:   }
  70: 
  71: 
  72:   public String toString()
  73:   {
  74:     return "/";
  75:   }
  76: 
  77:   public boolean isLeftOperation()
  78:   {
  79:     return true;
  80:   }
  81: 
  82:   /**
  83:    * Defines, whether the operation is associative. For associative operations,
  84:    * the evaluation order does not matter, if the operation appears more than
  85:    * once in an expression, and therefore we can optimize them a lot better than
  86:    * non-associative operations (ie. merge constant parts and precompute them
  87:    * once).
  88:    *
  89:    * @return true, if the operation is associative, false otherwise
  90:    */
  91:   public boolean isAssociative()
  92:   {
  93:     return false;
  94:   }
  95: 
  96: }