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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 java.io.IOException;
    11  import java.io.ObjectInputStream;
    12  import java.io.ObjectOutputStream;
    13  import java.io.Serializable;
    14
    15  import org.dom4j.tree.QNameCache;
    16  import org.dom4j.util.SingletonStrategy;
    17
    18  /***
    19   * <p>
    20   * <code>QName</code> represents a qualified name value of an XML element or
    21   * attribute. It consists of a local name and a {@link Namespace}instance. This
    22   * object is immutable.
    23   * </p>
    24   *
    25   * @author <a href="mailto:jstrachan@apache.org">James Strachan </a>
    26   */
    27  public class QName implements Serializable {
    28      /*** The Singleton instance */
    29      private static SingletonStrategy singleton = null;
    30
    31      static {
    32          try {
    33              String defaultSingletonClass = "org.dom4j.util.SimpleSingleton";
    34              Class clazz = null;
    35              try {
    36                  String singletonClass = defaultSingletonClass;
    37                  singletonClass = System.getProperty(
    38                          "org.dom4j.QName.singleton.strategy", singletonClass);
    39                  clazz = Class.forName(singletonClass);
    40              } catch (Exception exc1) {
    41                  try {
    42                      String singletonClass = defaultSingletonClass;
    43                      clazz = Class.forName(singletonClass);
    44                  } catch (Exception exc2) {
    45                  }
    46              }
    47              singleton = (SingletonStrategy) clazz.newInstance();
    48              singleton.setSingletonClassName(QNameCache.class.getName());
    49          } catch (Exception exc3) {
    50          }
    51      }
    52
    53      /*** The local name of the element or attribute */
    54      private String name;
    55
    56      /*** The qualified name of the element or attribute */
    57      private String qualifiedName;
    58
    59      /*** The Namespace of this element or attribute */
    60      private transient Namespace namespace;
    61
    62      /*** A cached version of the hashcode for efficiency */
    63      private int hashCode;
    64
    65      /*** The document factory used for this QName if specified or null */
    66      private DocumentFactory documentFactory;
    67
    68      public QName(String name) {
    69          this(name, Namespace.NO_NAMESPACE);
    70      }
    71
    72      public QName(String name, Namespace namespace) {
    73          this.name = (name == null) ? "" : name;
    74          this.namespace = (namespace == null) ? Namespace.NO_NAMESPACE
    75                  : namespace;
    76      }
    77
    78      public QName(String name, Namespace namespace, String qualifiedName) {
    79          this.name = (name == null) ? "" : name;
    80          this.qualifiedName = qualifiedName;
    81          this.namespace = (namespace == null) ? Namespace.NO_NAMESPACE
    82                  : namespace;
    83      }
    84
    85      public static QName get(String name) {
    86          return getCache().get(name);
    87      }
    88
    89      public static QName get(String name, Namespace namespace) {
    90          return getCache().get(name, namespace);
    91      }
    92
    93      public static QName get(String name, String prefix, String uri) {
    94          if (((prefix == null) || (prefix.length() == 0)) && (uri == null)) {
    95              return QName.get(name);
    96          } else if ((prefix == null) || (prefix.length() == 0)) {
    97              return getCache().get(name, Namespace.get(uri));
    98          } else if (uri == null) {
    99              return QName.get(name);
    100         } else {
    101             return getCache().get(name, Namespace.get(prefix, uri));
    102         }
    103     }
    104
    105     public static QName get(String qualifiedName, String uri) {
    106         if (uri == null) {
    107             return getCache().get(qualifiedName);
    108         } else {
    109             return getCache().get(qualifiedName, uri);
    110         }
    111     }
    112
    113     public static QName get(String localName, Namespace namespace,
    114             String qualifiedName) {
    115         return getCache().get(localName, namespace, qualifiedName);
    116     }
    117
    118     /***
    119      * DOCUMENT ME!
    120      *
    121      * @return the local name
    122      */
    123     public String getName() {
    124         return name;
    125     }
    126
    127     /***
    128      * DOCUMENT ME!
    129      *
    130      * @return the qualified name in the format <code>prefix:localName</code>
    131      */
    132     public String getQualifiedName() {
    133         if (qualifiedName == null) {
    134             String prefix = getNamespacePrefix();
    135
    136             if ((prefix != null) && (prefix.length() > 0)) {
    137                 qualifiedName = prefix + ":" + name;
    138             } else {
    139                 qualifiedName = name;
    140             }
    141         }
    142
    143         return qualifiedName;
    144     }
    145
    146     /***
    147      * DOCUMENT ME!
    148      *
    149      * @return the namespace of this QName
    150      */
    151     public Namespace getNamespace() {
    152         return namespace;
    153     }
    154
    155     /***
    156      * DOCUMENT ME!
    157      *
    158      * @return the namespace URI of this QName
    159      */
    160     public String getNamespacePrefix() {
    161         if (namespace == null) {
    162             return "";
    163         }
    164
    165         return namespace.getPrefix();
    166     }
    167
    168     /***
    169      * DOCUMENT ME!
    170      *
    171      * @return the namespace URI of this QName
    172      */
    173     public String getNamespaceURI() {
    174         if (namespace == null) {
    175             return "";
    176         }
    177
    178         return namespace.getURI();
    179     }
    180
    181     /***
    182      * DOCUMENT ME!
    183      *
    184      * @return the hash code based on the qualified name and the URI of the
    185      *         namespace.
    186      */
    187     public int hashCode() {
    188         if (hashCode == 0) {
    189             hashCode = getName().hashCode() ^ getNamespaceURI().hashCode();
    190
    191             if (hashCode == 0) {
    192                 hashCode = 0xbabe;
    193             }
    194         }
    195
    196         return hashCode;
    197     }
    198
    199     public boolean equals(Object object) {
    200         if (this == object) {
    201             return true;
    202         } else if (object instanceof QName) {
    203             QName that = (QName) object;
    204
    205             // we cache hash codes so this should be quick
    206             if (hashCode() == that.hashCode()) {
    207                 return getName().equals(that.getName())
    208                         && getNamespaceURI().equals(that.getNamespaceURI());
    209             }
    210         }
    211
    212         return false;
    213     }
    214
    215     public String toString() {
    216         return super.toString() + " [name: " + getName() + " namespace: \""
    217                 + getNamespace() + "\"]";
    218     }
    219
    220     /***
    221      * DOCUMENT ME!
    222      *
    223      * @return the factory that should be used for Elements of this QName
    224      */
    225     public DocumentFactory getDocumentFactory() {
    226         return documentFactory;
    227     }
    228
    229     public void setDocumentFactory(DocumentFactory documentFactory) {
    230         this.documentFactory = documentFactory;
    231     }
    232
    233     private void writeObject(ObjectOutputStream out) throws IOException {
    234         // We use writeObject() and not writeUTF() to minimize space
    235         // This allows for writing pointers to already written strings
    236         out.writeObject(namespace.getPrefix());
    237         out.writeObject(namespace.getURI());
    238
    239         out.defaultWriteObject();
    240     }
    241
    242     private void readObject(ObjectInputStream in) throws IOException,
    243             ClassNotFoundException {
    244         String prefix = (String) in.readObject();
    245         String uri = (String) in.readObject();
    246
    247         in.defaultReadObject();
    248
    249         namespace = Namespace.get(prefix, uri);
    250     }
    251
    252     private static QNameCache getCache() {
    253         QNameCache cache = (QNameCache) singleton.instance();
    254         return cache;
    255     }
    256 }
    257
    258
    259
    260 /*
    261  * Redistribution and use of this software and associated documentation
    262  * ("Software"), with or without modification, are permitted provided that the
    263  * following conditions are met:
    264  *
    265  * 1. Redistributions of source code must retain copyright statements and
    266  * notices. Redistributions must also contain a copy of this document.
    267  *
    268  * 2. Redistributions in binary form must reproduce the above copyright notice,
    269  * this list of conditions and the following disclaimer in the documentation
    270  * and/or other materials provided with the distribution.
    271  *
    272  * 3. The name "DOM4J" must not be used to endorse or promote products derived
    273  * from this Software without prior written permission of MetaStuff, Ltd. For
    274  * written permission, please contact dom4j-info@metastuff.com.
    275  *
    276  * 4. Products derived from this Software may not be called "DOM4J" nor may
    277  * "DOM4J" appear in their names without prior written permission of MetaStuff,
    278  * Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
    279  *
    280  * 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
    281  *
    282  * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND
    283  * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    284  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    285  * ARE DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE
    286  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
    287  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
    288  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
    289  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
    290  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
    291  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    292  * POSSIBILITY OF SUCH DAMAGE.
    293  *
    294  * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
    295  */