ExtensionNamespacesManager


1   /*
2    * Copyright 1999-2004 The Apache Software Foundation.
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *     http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  /*
17   * $Id: ExtensionNamespacesManager.java,v 1.8 2004/02/11 05:26:23 minchau Exp $
18   */
19  package org.apache.xalan.extensions;
20  
21  import java.util.Vector  ;
22  
23  import org.apache.xalan.templates.Constants;
24  
25  /**
26   * Used during assembly of a stylesheet to collect the information for each 
27   * extension namespace that is required during the transformation process 
28   * to generate an {@link ExtensionHandler}.
29   * 
30   */
31  public class ExtensionNamespacesManager
32  {
33    /**
34     * Vector of ExtensionNamespaceSupport objects to be used to generate ExtensionHandlers.
35     */
36    private Vector   m_extensions = new Vector  ();
37    /**
38     * Vector of ExtensionNamespaceSupport objects for predefined ExtensionNamespaces. Elements
39     * from this vector are added to the m_extensions vector when encountered in the stylesheet.
40     */
41    private Vector   m_predefExtensions = new Vector  (7);
42    /**
43     * Vector of extension namespaces for which sufficient information is not yet available to
44     * complete the registration process.
45     */
46    private Vector   m_unregisteredExtensions = new Vector  ();
47    
48    /**
49     * An ExtensionNamespacesManager is instantiated the first time an extension function or
50     * element is found in the stylesheet. During initialization, a vector of ExtensionNamespaceSupport
51     * objects is created, one for each predefined extension namespace.
52     */
53    public ExtensionNamespacesManager()
54    {
55      setPredefinedNamespaces();
56    }
57    
58    /**
59     * If necessary, register the extension namespace found compiling a function or 
60     * creating an extension element. 
61     * 
62     * If it is a predefined namespace, create a
63     * support object to simplify the instantiate of an appropriate ExtensionHandler
64     * during transformation runtime. Otherwise, add the namespace, if necessary,
65     * to a vector of undefined extension namespaces, to be defined later.
66     * 
67     */
68    public void registerExtension(String   namespace)
69    {
70      if (namespaceIndex(namespace, m_extensions) == -1)
71      {
72        int predef = namespaceIndex(namespace, m_predefExtensions);
73        if (predef !=-1)
74          m_extensions.addElement(m_predefExtensions.elementAt(predef));
75        else if (!(m_unregisteredExtensions.contains(namespace)))
76          m_unregisteredExtensions.addElement(namespace);       
77      }
78    }
79    
80    /**
81     * Register the extension namespace for an ElemExtensionDecl or ElemFunction,
82     * and prepare a support object to launch the appropriate ExtensionHandler at 
83     * transformation runtime.
84     */  
85    public void registerExtension(ExtensionNamespaceSupport extNsSpt)
86    {
87      String   namespace = extNsSpt.getNamespace();
88      if (namespaceIndex(namespace, m_extensions) == -1)
89      {
90        m_extensions.addElement(extNsSpt);
91        if (m_unregisteredExtensions.contains(namespace))
92          m_unregisteredExtensions.removeElement(namespace);
93      }
94      
95    }
96    
97    /**
98     * Get the index for a namespace entry in the extension namespace Vector, -1 if
99     * no such entry yet exists.
100    */
101   public int namespaceIndex(String   namespace, Vector   extensions)
102   {
103     for (int i = 0; i < extensions.size(); i++)
104     {
105       if (((ExtensionNamespaceSupport)extensions.elementAt(i)).getNamespace().equals(namespace))
106         return i;
107     }
108     return -1;
109   }
110   
111     
112   /**
113    * Get the vector of extension namespaces. Used to provide
114    * the extensions table access to a list of extension
115    * namespaces encountered during composition of a stylesheet.
116    */
117   public Vector   getExtensions()
118   {
119     return m_extensions;
120   }
121   
122   /**
123    * Attempt to register any unregistered extension namespaces.
124    */
125   public void registerUnregisteredNamespaces()
126   {
127     for (int i = 0; i < m_unregisteredExtensions.size(); i++)
128     {
129       String   ns = (String  )m_unregisteredExtensions.elementAt(i);
130       ExtensionNamespaceSupport extNsSpt = defineJavaNamespace(ns);
131       if (extNsSpt != null)
132         m_extensions.addElement(extNsSpt);
133     }    
134   }
135   
136     /**
137    * For any extension namespace that is not either predefined or defined 
138    * by a "component" declaration or exslt function declaration, attempt 
139    * to create an ExtensionNamespaceSuport object for the appropriate 
140    * Java class or Java package Extension Handler.
141    * 
142    * Called by StylesheetRoot.recompose(), after all ElemTemplate compose()
143    * operations have taken place, in order to set up handlers for
144    * the remaining extension namespaces.
145    * 
146    * @param ns The extension namespace URI.
147    * @return   An ExtensionNamespaceSupport object for this namespace
148    * (which defines the ExtensionHandler to be used), or null if such 
149    * an object cannot be created. 
150    *
151    * @throws javax.xml.transform.TransformerException
152    */
153   public ExtensionNamespaceSupport defineJavaNamespace(String   ns)
154   {
155     return defineJavaNamespace(ns, ns);
156   }
157   public ExtensionNamespaceSupport defineJavaNamespace(String   ns, String   classOrPackage)
158   {
159     if(null == ns || ns.trim().length() == 0) // defensive. I don't think it's needed.  -sb
160       return null;
161 
162     // Prepare the name of the actual class or package, stripping
163     // out any leading "class:".  Next, see if there is a /.  If so,
164     // only look at the text to the right of the rightmost /.
165     String   className = classOrPackage;
166     if (className.startsWith("class:"))
167       className = className.substring(6);
168 
169     int lastSlash = className.lastIndexOf("/");
170     if (-1 != lastSlash)
171       className = className.substring(lastSlash + 1);
172       
173     // The className can be null here, and can cause an error in getClassForName
174     // in JDK 1.8.
175     if(null == className || className.trim().length() == 0) 
176       return null;
177     
178     try
179     {
180       ExtensionHandler.getClassForName(className);
181       return new ExtensionNamespaceSupport(
182                            ns, 
183                            "org.apache.xalan.extensions.ExtensionHandlerJavaClass",                                         
184                            new Object  []{ns, "javaclass", className});
185     }
186     catch (ClassNotFoundException   e)
187     {
188       return new ExtensionNamespaceSupport(
189                             ns, 
190                             "org.apache.xalan.extensions.ExtensionHandlerJavaPackage",
191                             new Object  []{ns, "javapackage", className + "."});
192     }
193   }
194   
195 /*
196   public ExtensionNamespaceSupport getSupport(int index, Vector extensions)
197   {
198     return (ExtensionNamespaceSupport)extensions.elementAt(index);
199   }
200 */
201   
202   
203   /**
204    * Set up a Vector for predefined extension namespaces.
205    */
206   private void setPredefinedNamespaces()
207   {    
208     String   uri = Constants.S_EXTENSIONS_JAVA_URL;
209     String   handlerClassName = "org.apache.xalan.extensions.ExtensionHandlerJavaPackage";
210     String   lang = "javapackage";
211     String   lib = "";
212     m_predefExtensions.addElement(new ExtensionNamespaceSupport(uri, handlerClassName,
213                                              new Object  []{uri, lang, lib}));
214    
215     uri = Constants.S_EXTENSIONS_OLD_JAVA_URL;
216     m_predefExtensions.addElement(new ExtensionNamespaceSupport(uri, handlerClassName,
217                                              new Object  []{uri, lang, lib}));
218     
219     uri = Constants.S_EXTENSIONS_LOTUSXSL_JAVA_URL;
220     m_predefExtensions.addElement(new ExtensionNamespaceSupport(uri, handlerClassName,
221                                              new Object  []{uri, lang, lib}));
222     
223     uri = Constants.S_BUILTIN_EXTENSIONS_URL;
224     handlerClassName = "org.apache.xalan.extensions.ExtensionHandlerJavaClass";
225     lang = "javaclass"; // for remaining predefined extension namespaces.    
226     lib = "org.apache.xalan.lib.Extensions";
227     m_predefExtensions.addElement(new ExtensionNamespaceSupport(uri, handlerClassName,
228                                              new Object  []{uri, lang, lib}));
229     
230     uri = Constants.S_BUILTIN_OLD_EXTENSIONS_URL;
231     m_predefExtensions.addElement(new ExtensionNamespaceSupport(uri, handlerClassName,
232                                              new Object  []{uri, lang, lib}));
233     
234     // Xalan extension namespaces (redirect, pipe and SQL).
235     uri = Constants.S_EXTENSIONS_REDIRECT_URL;
236     lib = "org.apache.xalan.lib.Redirect";
237     m_predefExtensions.addElement(new ExtensionNamespaceSupport(uri, handlerClassName,
238                                              new Object  []{uri, lang, lib}));
239  
240     uri = Constants.S_EXTENSIONS_PIPE_URL;
241     lib = "org.apache.xalan.lib.PipeDocument";
242     m_predefExtensions.addElement(new ExtensionNamespaceSupport(uri, handlerClassName,
243                                              new Object  []{uri, lang, lib}));
244  
245     uri = Constants.S_EXTENSIONS_SQL_URL;
246     lib = "org.apache.xalan.lib.sql.XConnection";
247     m_predefExtensions.addElement(new ExtensionNamespaceSupport(uri, handlerClassName,
248                                              new Object  []{uri, lang, lib}));
249  
250     
251     //EXSLT namespaces (not including EXSLT function namespaces which are
252     // registered by the associated ElemFunction.
253     uri = Constants.S_EXSLT_COMMON_URL;
254     lib = "org.apache.xalan.lib.ExsltCommon";
255     m_predefExtensions.addElement(new ExtensionNamespaceSupport(uri, handlerClassName,
256                                              new Object  []{uri, lang, lib}));
257 
258     uri = Constants.S_EXSLT_MATH_URL;
259     lib = "org.apache.xalan.lib.ExsltMath";
260     m_predefExtensions.addElement(new ExtensionNamespaceSupport(uri, handlerClassName,
261                                              new Object  []{uri, lang, lib}));
262     
263     uri = Constants.S_EXSLT_SETS_URL;
264     lib = "org.apache.xalan.lib.ExsltSets";
265     m_predefExtensions.addElement(new ExtensionNamespaceSupport(uri, handlerClassName,
266                                              new Object  []{uri, lang, lib}));
267     
268     uri = Constants.S_EXSLT_DATETIME_URL;
269     lib = "org.apache.xalan.lib.ExsltDatetime";
270     m_predefExtensions.addElement(new ExtensionNamespaceSupport(uri, handlerClassName,
271                                              new Object  []{uri, lang, lib}));
272                                              
273     uri = Constants.S_EXSLT_DYNAMIC_URL;
274     lib = "org.apache.xalan.lib.ExsltDynamic";
275     m_predefExtensions.addElement(new ExtensionNamespaceSupport(uri, handlerClassName,
276                                              new Object  []{uri, lang, lib}));
277 
278     uri = Constants.S_EXSLT_STRINGS_URL;
279     lib = "org.apache.xalan.lib.ExsltStrings";
280     m_predefExtensions.addElement(new ExtensionNamespaceSupport(uri, handlerClassName,
281                                              new Object  []{uri, lang, lib}));                                             
282   }    
283   
284 }
285
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