Source for org.jfree.report.util.beans.ArrayValueConverter

   1: /**
   2:  * ========================================
   3:  * JFreeReport : a free Java report library
   4:  * ========================================
   5:  *
   6:  * Project Info:  http://reporting.pentaho.org/
   7:  *
   8:  * (C) Copyright 2000-2007, by Object Refinery Limited, 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:  * $Id: ArrayValueConverter.java 2725 2007-04-01 18:49:29Z taqua $
  27:  * ------------
  28:  * (C) Copyright 2000-2005, by Object Refinery Limited.
  29:  * (C) Copyright 2005-2007, by Pentaho Corporation.
  30:  */
  31: package org.jfree.report.util.beans;
  32: 
  33: import java.lang.reflect.Array;
  34: import java.util.ArrayList;
  35: 
  36: import org.jfree.report.util.CSVTokenizer;
  37: 
  38: /**
  39:  * An ValueConverter that handles Arrays. Conversion to arrays is done
  40:  * using a CSV string.
  41:  *
  42:  * @author Thomas Morgner
  43:  */
  44: public class ArrayValueConverter implements ValueConverter
  45: {
  46:   /** The converter for the array elements. */
  47:   private ValueConverter elementConverter;
  48:   /** The element type. */
  49:   private Class elementType;
  50: 
  51:   /**
  52:    * Creates a new ArrayValueConverter for the given element type and
  53:    * array type.
  54:    * @param arrayClass the array type
  55:    * @param elementConverter the value converter for the array elements.
  56:    */
  57:   public ArrayValueConverter (final Class arrayClass,
  58:                               final ValueConverter elementConverter)
  59:   {
  60:     if (elementConverter == null)
  61:     {
  62:       throw new NullPointerException("elementConverter must not be null");
  63:     }
  64:     if (arrayClass == null)
  65:     {
  66:       throw new NullPointerException("arrayClass must not be null");
  67:     }
  68:     this.elementType = arrayClass;
  69:     this.elementConverter = elementConverter;
  70:   }
  71: 
  72:   /**
  73:    * Converts an object to an attribute value.
  74:    *
  75:    * @param o the object.
  76:    * @return the attribute value.
  77:    * @throws BeanException if there was an error during the conversion.
  78:    */
  79:   public String toAttributeValue (final Object o) throws BeanException
  80:   {
  81:     final int size = Array.getLength(o);
  82:     final StringBuffer buffer = new StringBuffer();
  83:     for (int i = 0; i < size; i++)
  84:     {
  85:       if (i != 0)
  86:       {
  87:         buffer.append(",");
  88:       }
  89:       buffer.append(elementConverter.toAttributeValue(Array.get(o, i)));
  90:     }
  91:     return buffer.toString();
  92:   }
  93: 
  94:   /**
  95:    * Converts a string to a property value.
  96:    *
  97:    * @param s the string.
  98:    * @return a property value.
  99:    * @throws BeanException if there was an error during the conversion.
 100:    */
 101:   public Object toPropertyValue (final String s) throws BeanException
 102:   {
 103:     final CSVTokenizer tokenizer = new CSVTokenizer(s);
 104:     final ArrayList elements = new ArrayList();
 105:     while (tokenizer.hasMoreTokens())
 106:     {
 107:       final String token = tokenizer.nextToken();
 108:       elements.add(elementConverter.toPropertyValue(token));
 109:     }
 110:     final Object retval =
 111:             Array.newInstance(elementType, elements.size());
 112:     for (int i = 0; i < elements.size(); i++)
 113:     {
 114:       final Object o = elements.get(i);
 115:       Array.set(retval, i, o);
 116:     }
 117:     return retval;
 118:   }
 119: }