libjava/gnu/xml/dom/DomXPathResult.java

   1 /* DomXPathResult.java --
   2    Copyright (C) 2004 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38 package gnu.xml.dom;
  39
  40 import java.util.Collection;
  41 import java.util.Iterator;
  42 import org.w3c.dom.Node;
  43 import org.w3c.dom.xpath.XPathException;
  44 import org.w3c.dom.xpath.XPathResult;
  45
  46 /**
  47  * An XPath result object.
  48  *
  49  * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
  50  */
  51 class DomXPathResult
  52 implements XPathResult
  53 {
  54
  55   final Object value;
  56   final short type;
  57   Iterator iterator;
  58
  59   DomXPathResult (Object value, short requestedType)
  60   {
  61     this.value = value;
  62     if (value instanceof Boolean)
  63       {
  64         type = XPathResult.BOOLEAN_TYPE;
  65       }
  66     else if (value instanceof Double)
  67       {
  68         type = XPathResult.NUMBER_TYPE;
  69       }
  70     else if (value instanceof String)
  71       {
  72         type = XPathResult.STRING_TYPE;
  73       }
  74     else if (value instanceof Collection)
  75       {
  76         Collection ns = (Collection) value;
  77         switch (requestedType)
  78           {
  79           case XPathResult.ANY_TYPE:
  80           case XPathResult.ANY_UNORDERED_NODE_TYPE:
  81             type = (ns.size () == 1) ? XPathResult.FIRST_ORDERED_NODE_TYPE :
  82               XPathResult.ORDERED_NODE_ITERATOR_TYPE;
  83             break;
  84           default:
  85             type = requestedType;
  86           }
  87         iterator = ns.iterator ();
  88       }
  89     else
  90       {
  91         throw new IllegalArgumentException ();
  92       }
  93   }
  94
  95   public boolean getBooleanValue()
  96   {
  97     if (type == XPathResult.BOOLEAN_TYPE)
  98       {
  99         return ((Boolean) value).booleanValue ();
 100       }
 101     throw new XPathException (XPathException.TYPE_ERR, value.toString ());
 102   }
 103
 104   public boolean getInvalidIteratorState()
 105   {
 106     return iterator == null;
 107   }
 108
 109   public double getNumberValue()
 110   {
 111     if (type == XPathResult.NUMBER_TYPE)
 112       {
 113         return ((Double) value).doubleValue ();
 114       }
 115     throw new XPathException (XPathException.TYPE_ERR, value.toString ());
 116   }
 117
 118   public short getResultType()
 119   {
 120     return type;
 121   }
 122
 123   public Node getSingleNodeValue()
 124   {
 125     switch (type)
 126       {
 127       case XPathResult.FIRST_ORDERED_NODE_TYPE:
 128       case XPathResult.ORDERED_NODE_ITERATOR_TYPE:
 129       case XPathResult.ORDERED_NODE_SNAPSHOT_TYPE:
 130       case XPathResult.UNORDERED_NODE_ITERATOR_TYPE:
 131       case XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE:
 132         Collection ns = (Collection) value;
 133         if (ns.isEmpty ())
 134           {
 135             return null;
 136           }
 137         else
 138           {
 139             return (Node) ns.iterator ().next ();
 140           }
 141       }
 142     throw new XPathException (XPathException.TYPE_ERR, value.toString ());
 143   }
 144
 145   public int getSnapshotLength()
 146   {
 147     switch (type)
 148       {
 149       case XPathResult.FIRST_ORDERED_NODE_TYPE:
 150       case XPathResult.ORDERED_NODE_ITERATOR_TYPE:
 151       case XPathResult.ORDERED_NODE_SNAPSHOT_TYPE:
 152       case XPathResult.UNORDERED_NODE_ITERATOR_TYPE:
 153       case XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE:
 154         return ((Collection) value).size ();
 155       }
 156     throw new XPathException (XPathException.TYPE_ERR, value.toString ());
 157   }
 158
 159   public String getStringValue()
 160   {
 161     if (type == XPathResult.STRING_TYPE)
 162       {
 163         return (String) value;
 164       }
 165     throw new XPathException (XPathException.TYPE_ERR, value.toString ());
 166   }
 167
 168   public Node iterateNext()
 169   {
 170     if (iterator != null)
 171       {
 172         if (iterator.hasNext ())
 173           {
 174             return (Node) iterator.next ();
 175           }
 176         else
 177           {
 178             iterator = null;
 179             return null;
 180           }
 181       }
 182     throw new XPathException (XPathException.TYPE_ERR, value.toString ());
 183   }
 184
 185   public Node snapshotItem(int index)
 186   {
 187     switch (type)
 188       {
 189       case XPathResult.FIRST_ORDERED_NODE_TYPE:
 190       case XPathResult.ORDERED_NODE_ITERATOR_TYPE:
 191       case XPathResult.ORDERED_NODE_SNAPSHOT_TYPE:
 192       case XPathResult.UNORDERED_NODE_ITERATOR_TYPE:
 193       case XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE:
 194         Collection ns = (Collection) value;
 195         Node[] nodes = new Node[ns.size ()];
 196         ns.toArray (nodes);
 197         return nodes[index];
 198       }
 199     throw new XPathException (XPathException.TYPE_ERR, value.toString ());
 200   }
 201
 202   public String toString ()
 203   {
 204     return getClass ().getName () + "[type=" + typeName (type) + ",value=" +
 205       value + ']';
 206   }
 207
 208   private String typeName (short type)
 209   {
 210     switch (type)
 211       {
 212       case XPathResult.BOOLEAN_TYPE:
 213         return "BOOLEAN_TYPE";
 214       case XPathResult.NUMBER_TYPE:
 215         return "NUMBER_TYPE";
 216       case XPathResult.STRING_TYPE:
 217         return "STRING_TYPE";
 218       case XPathResult.FIRST_ORDERED_NODE_TYPE:
 219         return "FIRST_ORDERED_NODE_TYPE";
 220       case XPathResult.ORDERED_NODE_ITERATOR_TYPE:
 221         return "ORDERED_NODE_ITERATOR_TYPE";
 222       case XPathResult.ORDERED_NODE_SNAPSHOT_TYPE:
 223         return "ORDERED_NODE_SNAPSHOT_TYPE";
 224       case XPathResult.UNORDERED_NODE_ITERATOR_TYPE:
 225         return "UNORDERED_NODE_ITERATOR_TYPE";
 226       case XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE:
 227         return "UNORDERED_NODE_SNAPSHOT_TYPE";
 228       default:
 229         return "(unknown)";
 230       }
 231   }
 232
 233 }