gov/nasa/worldwind/wms/SimpleNamespaceContext.java

   1 /*
   2 Copyright (C) 2001, 2006 United States Government
   3 as represented by the Administrator of the
   4 National Aeronautics and Space Administration.
   5 All Rights Reserved.
   6 */
   7 package gov.nasa.worldwind.wms;
   8
   9 import javax.xml.XMLConstants;
  10 import javax.xml.namespace.NamespaceContext;
  11 import java.util.*;
  12
  13 /**
  14  * @author Java & XML 3e
  15  * @version $Id: SimpleNamespaceContext.java 2471 2007-07-31 21:50:57Z tgaskins $
  16  */
  17 public class SimpleNamespaceContext implements NamespaceContext
  18 {
  19
  20     private Map<String, String> urisByPrefix = new HashMap<String, String>();
  21     private Map<String, Set<String>> prefixesByURI = new HashMap<String, Set<String>>();
  22
  23     public SimpleNamespaceContext()
  24     {
  25         // prepopulate with xml and xmlns prefixes
  26         // per JavaDoc of NamespaceContext interface
  27         addNamespace(XMLConstants.XML_NS_PREFIX, XMLConstants.XML_NS_URI);
  28         addNamespace(XMLConstants.XMLNS_ATTRIBUTE, XMLConstants.XMLNS_ATTRIBUTE_NS_URI);
  29         addNamespace("xlink", "http://www.w3.org/1999/xlink");
  30         addNamespace("wms", "http://www.opengis.net/wms");
  31         addNamespace(XMLConstants.DEFAULT_NS_PREFIX, "http://www.opengis.net/wms");
  32     }
  33
  34     public synchronized void addNamespace(String prefix, String namespaceURI)
  35     {
  36         urisByPrefix.put(prefix, namespaceURI);
  37         if (prefixesByURI.containsKey(namespaceURI))
  38         {
  39             (prefixesByURI.get(namespaceURI)).add(prefix);
  40         }
  41         else
  42         {
  43             Set<String> set = new HashSet<String>();
  44             set.add(prefix);
  45             prefixesByURI.put(namespaceURI, set);
  46         }
  47     }
  48
  49     public String getNamespaceURI(String prefix)
  50     {
  51         if (prefix == null)
  52             throw new IllegalArgumentException("prefix cannot be null");
  53         if (urisByPrefix.containsKey(prefix))
  54             return urisByPrefix.get(prefix);
  55         else
  56             return XMLConstants.NULL_NS_URI;
  57     }
  58
  59     public String getPrefix(String namespaceURI)
  60     {
  61         return (String) getPrefixes(namespaceURI).next();
  62     }
  63
  64     public Iterator getPrefixes(String namespaceURI)
  65     {
  66         if (namespaceURI == null)
  67             throw new IllegalArgumentException("namespaceURI cannot be null");
  68         if (prefixesByURI.containsKey(namespaceURI))
  69         {
  70             return (prefixesByURI.get(namespaceURI)).iterator();
  71         }
  72         else
  73         {
  74             return Collections.EMPTY_SET.iterator();
  75         }
  76     }
  77 }