Namespace xref

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    1   /*
    2    * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
    3    *
    4    * This software is open source.
    5    * See the bottom of this file for the licence.
    6    */
    7
    8   package org.dom4j;
    9
    10  import org.dom4j.tree.AbstractNode;
    11  import org.dom4j.tree.DefaultNamespace;
    12  import org.dom4j.tree.NamespaceCache;
    13
    14  /***
    15   * <p>
    16   * <code>Namespace</code> is a Flyweight Namespace that can be shared amongst
    17   * nodes.
    18   * </p>
    19   *
    20   * @author <a href="mailto:jstrachan@apache.org">James Strachan </a>
    21   * @version $Revision: 1.22 $
    22   */
    23  public class Namespace extends AbstractNode {
    24      /*** Cache of Namespace instances */
    25      protected static final NamespaceCache CACHE = new NamespaceCache();
    26
    27      /*** XML Namespace */
    28      public static final Namespace XML_NAMESPACE = CACHE.get("xml",
    29              "http://www.w3.org/XML/1998/namespace");
    30
    31      /*** No Namespace present */
    32      public static final Namespace NO_NAMESPACE = CACHE.get("", "");
    33
    34      /*** The prefix mapped to this namespace */
    35      private String prefix;
    36
    37      /*** The URI for this namespace */
    38      private String uri;
    39
    40      /*** A cached version of the hashcode for efficiency */
    41      private int hashCode;
    42
    43      /***
    44       * DOCUMENT ME!
    45       *
    46       * @param prefix
    47       *            is the prefix for this namespace
    48       * @param uri
    49       *            is the URI for this namespace
    50       */
    51      public Namespace(String prefix, String uri) {
    52          this.prefix = (prefix != null) ? prefix : "";
    53          this.uri = (uri != null) ? uri : "";
    54      }
    55
    56      /***
    57       * A helper method to return the Namespace instance for the given prefix and
    58       * URI
    59       *
    60       * @param prefix
    61       *            DOCUMENT ME!
    62       * @param uri
    63       *            DOCUMENT ME!
    64       *
    65       * @return an interned Namespace object
    66       */
    67      public static Namespace get(String prefix, String uri) {
    68          return CACHE.get(prefix, uri);
    69      }
    70
    71      /***
    72       * A helper method to return the Namespace instance for no prefix and the
    73       * URI
    74       *
    75       * @param uri
    76       *            DOCUMENT ME!
    77       *
    78       * @return an interned Namespace object
    79       */
    80      public static Namespace get(String uri) {
    81          return CACHE.get(uri);
    82      }
    83
    84      public short getNodeType() {
    85          return NAMESPACE_NODE;
    86      }
    87
    88      /***
    89       * DOCUMENT ME!
    90       *
    91       * @return the hash code based on the qualified name and the URI of the
    92       *         namespace.
    93       */
    94      public int hashCode() {
    95          if (hashCode == 0) {
    96              hashCode = createHashCode();
    97          }
    98
    99          return hashCode;
    100     }
    101
    102     /***
    103      * Factory method to create the hashcode allowing derived classes to change
    104      * the behaviour
    105      *
    106      * @return DOCUMENT ME!
    107      */
    108     protected int createHashCode() {
    109         int result = uri.hashCode() ^ prefix.hashCode();
    110
    111         if (result == 0) {
    112             result = 0xbabe;
    113         }
    114
    115         return result;
    116     }
    117
    118     /***
    119      * Checks whether this Namespace equals the given Namespace. Two Namespaces
    120      * are equals if their URI and prefix are equal.
    121      *
    122      * @param object
    123      *            DOCUMENT ME!
    124      *
    125      * @return DOCUMENT ME!
    126      */
    127     public boolean equals(Object object) {
    128         if (this == object) {
    129             return true;
    130         } else if (object instanceof Namespace) {
    131             Namespace that = (Namespace) object;
    132
    133             // we cache hash codes so this should be quick
    134             if (hashCode() == that.hashCode()) {
    135                 return uri.equals(that.getURI())
    136                         && prefix.equals(that.getPrefix());
    137             }
    138         }
    139
    140         return false;
    141     }
    142
    143     public String getText() {
    144         return uri;
    145     }
    146
    147     public String getStringValue() {
    148         return uri;
    149     }
    150
    151     /***
    152      * DOCUMENT ME!
    153      *
    154      * @return the prefix for this <code>Namespace</code>.
    155      */
    156     public String getPrefix() {
    157         return prefix;
    158     }
    159
    160     /***
    161      * DOCUMENT ME!
    162      *
    163      * @return the URI for this <code>Namespace</code>.
    164      */
    165     public String getURI() {
    166         return uri;
    167     }
    168
    169     public String getXPathNameStep() {
    170         if ((prefix != null) && !"".equals(prefix)) {
    171             return "namespace::" + prefix;
    172         }
    173
    174         return "namespace::*[name()='']";
    175     }
    176
    177     public String getPath(Element context) {
    178         StringBuffer path = new StringBuffer(10);
    179         Element parent = getParent();
    180
    181         if ((parent != null) && (parent != context)) {
    182             path.append(parent.getPath(context));
    183             path.append('/');
    184         }
    185
    186         path.append(getXPathNameStep());
    187
    188         return path.toString();
    189     }
    190
    191     public String getUniquePath(Element context) {
    192         StringBuffer path = new StringBuffer(10);
    193         Element parent = getParent();
    194
    195         if ((parent != null) && (parent != context)) {
    196             path.append(parent.getUniquePath(context));
    197             path.append('/');
    198         }
    199
    200         path.append(getXPathNameStep());
    201
    202         return path.toString();
    203     }
    204
    205     public String toString() {
    206         return super.toString() + " [Namespace: prefix " + getPrefix()
    207                 + " mapped to URI \"" + getURI() + "\"]";
    208     }
    209
    210     public String asXML() {
    211         StringBuffer asxml = new StringBuffer(10);
    212         String pref = getPrefix();
    213
    214         if ((pref != null) && (pref.length() > 0)) {
    215             asxml.append("xmlns:");
    216             asxml.append(pref);
    217             asxml.append("=\"");
    218         } else {
    219             asxml.append("xmlns=\"");
    220         }
    221
    222         asxml.append(getURI());
    223         asxml.append("\"");
    224
    225         return asxml.toString();
    226     }
    227
    228     public void accept(Visitor visitor) {
    229         visitor.visit(this);
    230     }
    231
    232     protected Node createXPathResult(Element parent) {
    233         return new DefaultNamespace(parent, getPrefix(), getURI());
    234     }
    235 }
    236
    237 /*
    238  * Redistribution and use of this software and associated documentation
    239  * ("Software"), with or without modification, are permitted provided that the
    240  * following conditions are met:
    241  *
    242  * 1. Redistributions of source code must retain copyright statements and
    243  * notices. Redistributions must also contain a copy of this document.
    244  *
    245  * 2. Redistributions in binary form must reproduce the above copyright notice,
    246  * this list of conditions and the following disclaimer in the documentation
    247  * and/or other materials provided with the distribution.
    248  *
    249  * 3. The name "DOM4J" must not be used to endorse or promote products derived
    250  * from this Software without prior written permission of MetaStuff, Ltd. For
    251  * written permission, please contact dom4j-info@metastuff.com.
    252  *
    253  * 4. Products derived from this Software may not be called "DOM4J" nor may
    254  * "DOM4J" appear in their names without prior written permission of MetaStuff,
    255  * Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
    256  *
    257  * 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
    258  *
    259  * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND
    260  * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    261  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    262  * ARE DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE
    263  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
    264  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
    265  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
    266  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
    267  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
    268  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    269  * POSSIBILITY OF SUCH DAMAGE.
    270  *
    271  * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
    272  */