Source for org.jfree.formula.operators.MultiplyOperator

   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: MultiplyOperator.java 2752 2007-04-10 14:10:41Z 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: 
  37: /**
  38:  * Creation-Date: 31.10.2006, 16:34:11
  39:  *
  40:  * @author Thomas Morgner
  41:  */
  42: public class MultiplyOperator extends AbstractNumericOperator
  43: {
  44:   public MultiplyOperator()
  45:   {
  46:   }
  47: 
  48:   protected Number evaluate(final Number number1, final Number number2) throws EvaluationException
  49:   {
  50:     if ((number1 instanceof Integer || number1 instanceof Short) &&
  51:         (number2 instanceof Integer || number2 instanceof Short))
  52:     {
  53:       // this is still safe ..
  54:       return new BigDecimal(number1.longValue() * number2.longValue());
  55:     }
  56: 
  57:     final BigDecimal bd1 = new BigDecimal(number1.toString());
  58:     final BigDecimal bd2 = new BigDecimal(number2.toString());
  59:     return bd1.multiply(bd2);
  60:   }
  61: 
  62:   public int getLevel()
  63:   {
  64:     return 100;
  65:   }
  66: 
  67:   public String toString()
  68:   {
  69:     return "*";
  70:   }
  71: 
  72:   public boolean isLeftOperation()
  73:   {
  74:     return true;
  75:   }
  76: 
  77:   /**
  78:    * Defines, whether the operation is associative. For associative operations,
  79:    * the evaluation order does not matter, if the operation appears more than
  80:    * once in an expression, and therefore we can optimize them a lot better than
  81:    * non-associative operations (ie. merge constant parts and precompute them
  82:    * once).
  83:    *
  84:    * @return true, if the operation is associative, false otherwise
  85:    */
  86:   public boolean isAssociative()
  87:   {
  88:     return true;
  89:   }
  90: 
  91: }