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

   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: GenericValueConverter.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.beans.IntrospectionException;
  34: import java.beans.PropertyDescriptor;
  35: import java.beans.PropertyEditor;
  36: 
  37: /**
  38:  * A class that handles the conversion of {@link Integer} attributes to and from their
  39:  * {@link String} representation.
  40:  *
  41:  * @author Thomas Morgner
  42:  */
  43: public class GenericValueConverter implements ValueConverter
  44: {
  45:   private PropertyDescriptor propertyDescriptor;
  46:   private PropertyEditor propertyEditor;
  47: 
  48:   /**
  49:    * Creates a new value converter.
  50:    */
  51:   public GenericValueConverter (final PropertyDescriptor pd)
  52:           throws IntrospectionException
  53:   {
  54:     if (pd == null)
  55:     {
  56:       throw new NullPointerException("PropertyDescriptor must not be null.");
  57:     }
  58:     if (pd.getPropertyEditorClass() == null)
  59:     {
  60:       throw new IntrospectionException("Property has no editor.");
  61:     }
  62:     this.propertyDescriptor = pd;
  63:     this.propertyEditor = createPropertyEditor(pd);
  64:   }
  65: 
  66:   private PropertyEditor createPropertyEditor (final PropertyDescriptor pi)
  67:           throws IntrospectionException
  68:   {
  69:     final Class c = pi.getPropertyEditorClass();
  70:     try
  71:     {
  72:       return (PropertyEditor) c.newInstance();
  73:     }
  74:     catch (Exception e)
  75:     {
  76:       throw new IntrospectionException("Unable to create PropertyEditor.");
  77:     }
  78:   }
  79: 
  80: 
  81:   /**
  82:    * Converts the attribute to a string.
  83:    *
  84:    * @param o the attribute ({@link Integer} expected).
  85:    * @return A string representing the {@link Integer} value.
  86:    * @throws BeanException if there was an error during the conversion.
  87:    */
  88:   public String toAttributeValue (final Object o) throws BeanException
  89:   {
  90:     if (BeanUtility.getPropertyType(propertyDescriptor).isInstance(o) == false)
  91:     {
  92:       throw new ClassCastException("Give me a real type.");
  93:     }
  94: 
  95:     propertyEditor.setValue(o);
  96:     return propertyEditor.getAsText();
  97:   }
  98: 
  99:   /**
 100:    * Converts a string to a {@link Integer}.
 101:    *
 102:    * @param s the string.
 103:    * @return a {@link Integer}.
 104:    */
 105:   public Object toPropertyValue (final String s)
 106:   {
 107:     propertyEditor.setAsText(s);
 108:     return propertyEditor.getValue();
 109:   }
 110: }