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3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4    *
5    * This code is free software; you can redistribute it and/or modify it
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7    * published by the Free Software Foundation.  Oracle designates this
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9    * by Oracle in the LICENSE file that accompanied this code.
10   *
11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
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17   * You should have received a copy of the GNU General Public License version
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20   *
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24   */
25  
26  package com.sun.xml.internal.ws.util;
27  
28  import java.util.ArrayList;
29  import java.util.EmptyStackException;
30  import java.util.HashMap;
31  import java.util.Iterator;
32  import java.util.List;
33  import java.util.Map;
34  
35  import com.sun.xml.internal.ws.encoding.soap.streaming.SOAPNamespaceConstants;
36  
37  /**
38   * Encapsulate Namespace logic for use by SAX drivers.
39   *
40   * <blockquote>
41   * <em>This module, both source code and documentation, is in the
42   * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
43   * </blockquote>
44   *
45   * <p>This class encapsulates the logic of Namespace processing:
46   * it tracks the declarations currently in force for each context
47   * and automatically processes qualified XML 1.0 names into their
48   * Namespace parts; it can also be used in reverse for generating
49   * XML 1.0 from Namespaces.</p>
50   *
51   * <p>Namespace support objects are reusable, but the reset method
52   * must be invoked between each session.</p>
53   *
54   * <p>Here is a simple session:</p>
55   *
56   * <pre>
57   * String parts[] = new String[3];
58   * NamespaceSupport support = new NamespaceSupport();
59   *
60   * support.pushContext();
61   * support.declarePrefix("", "http://www.w3.org/1999/xhtml");
62   * support.declarePrefix("dc", "http://www.purl.org/dc#");
63   *
64   * String parts[] = support.processName("p", parts, false);
65   * System.out.println("Namespace URI: " + parts[0]);
66   * System.out.println("Local name: " + parts[1]);
67   * System.out.println("Raw name: " + parts[2]);
68  
69   * String parts[] = support.processName("dc:title", parts, false);
70   * System.out.println("Namespace URI: " + parts[0]);
71   * System.out.println("Local name: " + parts[1]);
72   * System.out.println("Raw name: " + parts[2]);
73  
74   * support.popContext();
75   * </pre>
76   *
77   * <p>Note that this class is optimized for the use case where most
78   * elements do not contain Namespace declarations: if the same
79   * prefix/URI mapping is repeated for each context (for example), this
80   * class will be somewhat less efficient.</p>
81   *
82   * @author David Megginson
83   * @author WS Development Team
84   */
85  public final class NamespaceSupport {
86  
87      /* added two new methods, slideContextUp() and slideContextDown()
88       * needed to implement the revised streaming parser class (Parser2)
89       */
90  
91      ////////////////////////////////////////////////////////////////////
92      // Constants.
93      ////////////////////////////////////////////////////////////////////
94  
95      /**
96       * The XML Namespace as a constant.
97       *
98       * <p>This is the Namespace URI that is automatically mapped
99       * to the "xml" prefix.</p>
100      */
101     public final static String XMLNS = "http://www.w3.org/XML/1998/namespace";
102 
103     /**
104      * An empty enumeration.
105      */
106     private final static Iterable<String> EMPTY_ENUMERATION =
107         new ArrayList<String>();
108 
109     ////////////////////////////////////////////////////////////////////
110     // Constructor.
111     ////////////////////////////////////////////////////////////////////
112 
113     /**
114      * Create a new Namespace support object.
115      */
116     public NamespaceSupport() {
117         reset();
118     }
119 
120     // PBG May 6 2002 added a copy constructor to support recording
121     public NamespaceSupport(NamespaceSupport that) {
122         contexts = new Context[that.contexts.length];
123         currentContext = null;
124         contextPos = that.contextPos;
125 
126         Context currentParent = null;
127 
128         for (int i = 0; i < that.contexts.length; i++) {
129             Context thatContext = that.contexts[i];
130 
131             if (thatContext == null) {
132                 contexts[i] = null;
133                 continue;
134             }
135 
136             Context thisContext = new Context(thatContext, currentParent);
137             contexts[i] = thisContext;
138             if (that.currentContext == thatContext) {
139                 currentContext = thisContext;
140             }
141 
142             currentParent = thisContext;
143         }
144     }
145 
146     ////////////////////////////////////////////////////////////////////
147     // Context management.
148     ////////////////////////////////////////////////////////////////////
149 
150     /**
151      * Reset this Namespace support object for reuse.
152      *
153      * <p>It is necessary to invoke this method before reusing the
154      * Namespace support object for a new session.</p>
155      */
156     public void reset() {
157         contexts = new Context[32];
158         contextPos = 0;
159         contexts[contextPos] = currentContext = new Context();
160         currentContext.declarePrefix("xml", XMLNS);
161     }
162 
163     /**
164      * Start a new Namespace context.
165      *
166      * <p>Normally, you should push a new context at the beginning
167      * of each XML element: the new context will automatically inherit
168      * the declarations of its parent context, but it will also keep
169      * track of which declarations were made within this context.</p>
170      *
171      * <p>The Namespace support object always starts with a base context
172      * already in force: in this context, only the "xml" prefix is
173      * declared.</p>
174      *
175      * @see #popContext
176      */
177     public void pushContext() {
178         int max = contexts.length;
179         contextPos++;
180 
181         // Extend the array if necessary
182         if (contextPos >= max) {
183             Context newContexts[] = new Context[max * 2];
184             System.arraycopy(contexts, 0, newContexts, 0, max);
185             contexts = newContexts;
186         }
187 
188         // Allocate the context if necessary.
189         currentContext = contexts[contextPos];
190         if (currentContext == null) {
191             contexts[contextPos] = currentContext = new Context();
192         }
193 
194         // Set the parent, if any.
195         if (contextPos > 0) {
196             currentContext.setParent(contexts[contextPos - 1]);
197         }
198     }
199 
200     /**
201      * Revert to the previous Namespace context.
202      *
203      * <p>Normally, you should pop the context at the end of each
204      * XML element.  After popping the context, all Namespace prefix
205      * mappings that were previously in force are restored.</p>
206      *
207      * <p>You must not attempt to declare additional Namespace
208      * prefixes after popping a context, unless you push another
209      * context first.</p>
210      *
211      * @see #pushContext
212      */
213     public void popContext() {
214         contextPos--;
215         if (contextPos < 0) {
216             throw new EmptyStackException();
217         }
218         currentContext = contexts[contextPos];
219     }
220 
221     /*
222      * added for the revised streaming parser class (Parser2)
223      * Move the context artificially up one level (i.e. contracting it).
224      */
225     public void slideContextUp() {
226         contextPos--;
227         currentContext = contexts[contextPos];
228     }
229 
230     /*
231      * added for the revised streaming parser class (Parser2)
232      * Move the context artificially down one level (i.e. expanding it).
233      */
234     public void slideContextDown() {
235         contextPos++;
236 
237         if (contexts[contextPos] == null) {
238             // trying to slide to a context that was never created
239             contexts[contextPos] = contexts[contextPos - 1];
240         }
241 
242         currentContext = contexts[contextPos];
243     }
244 
245     ////////////////////////////////////////////////////////////////////
246     // Operations within a context.
247     ////////////////////////////////////////////////////////////////////
248 
249     /**
250      * Declare a Namespace prefix.
251      *
252      * <p>This method declares a prefix in the current Namespace
253      * context; the prefix will remain in force until this context
254      * is popped, unless it is shadowed in a descendant context.</p>
255      *
256      * <p>To declare a default Namespace, use the empty string.  The
257      * prefix must not be "xml" or "xmlns".</p>
258      *
259      * <p>Note that you must <em>not</em> declare a prefix after
260      * you've pushed and popped another Namespace.</p>
261      *
262      * <p>Note that there is an asymmetry in this library: while {@link
263      * #getPrefix getPrefix} will not return the default "" prefix,
264      * even if you have declared one; to check for a default prefix,
265      * you have to look it up explicitly using {@link #getURI getURI}.
266      * This asymmetry exists to make it easier to look up prefixes
267      * for attribute names, where the default prefix is not allowed.</p>
268      *
269      * @param prefix The prefix to declare, or null for the empty
270      *        string.
271      * @param uri The Namespace URI to associate with the prefix.
272      * @return true if the prefix was legal, false otherwise
273      * @see #processName
274      * @see #getURI
275      * @see #getPrefix
276      */
277     public boolean declarePrefix(String prefix, String uri) {
278         // bugfix#: 4989753
279         if ((prefix.equals("xml") && !uri.equals(SOAPNamespaceConstants.XMLNS))
280             || prefix.equals("xmlns")) {
281             return false;
282         } else {
283             currentContext.declarePrefix(prefix, uri);
284             return true;
285         }
286     }
287 
288     /**
289      * Process a raw XML 1.0 name.
290      *
291      * <p>This method processes a raw XML 1.0 name in the current
292      * context by removing the prefix and looking it up among the
293      * prefixes currently declared.  The return value will be the
294      * array supplied by the caller, filled in as follows:</p>
295      *
296      * <dl>
297      * <dt>parts[0]</dt>
298      * <dd>The Namespace URI, or an empty string if none is
299      *  in use.</dd>
300      * <dt>parts[1]</dt>
301      * <dd>The local name (without prefix).</dd>
302      * <dt>parts[2]</dt>
303      * <dd>The original raw name.</dd>
304      * </dl>
305      *
306      * <p>All of the strings in the array will be internalized.  If
307      * the raw name has a prefix that has not been declared, then
308      * the return value will be null.</p>
309      *
310      * <p>Note that attribute names are processed differently than
311      * element names: an unprefixed element name will received the
312      * default Namespace (if any), while an unprefixed element name
313      * will not.</p>
314      *
315      * @param qName The raw XML 1.0 name to be processed.
316      * @param parts An array supplied by the caller, capable of
317      *        holding at least three members.
318      * @param isAttribute A flag indicating whether this is an
319      *        attribute name (true) or an element name (false).
320      * @return The supplied array holding three internalized strings
321      *        representing the Namespace URI (or empty string), the
322      *        local name, and the raw XML 1.0 name; or null if there
323      *        is an undeclared prefix.
324      * @see #declarePrefix
325      * @see java.lang.String#intern */
326     public String[] processName(
327         String qName,
328         String parts[],
329         boolean isAttribute) {
330         String myParts[] = currentContext.processName(qName, isAttribute);
331         if (myParts == null) {
332             return null;
333         } else {
334             parts[0] = myParts[0];
335             parts[1] = myParts[1];
336             parts[2] = myParts[2];
337             return parts;
338         }
339     }
340 
341     /**
342      * Look up a prefix and get the currently-mapped Namespace URI.
343      *
344      * <p>This method looks up the prefix in the current context.
345      * Use the empty string ("") for the default Namespace.</p>
346      *
347      * @param prefix The prefix to look up.
348      * @return The associated Namespace URI, or null if the prefix
349      *         is undeclared in this context.
350      * @see #getPrefix
351      * @see #getPrefixes
352      */
353     public String getURI(String prefix) {
354         return currentContext.getURI(prefix);
355     }
356 
357     /**
358      * Return an enumeration of all prefixes currently declared.
359      *
360      * <p><strong>Note:</strong> if there is a default prefix, it will not be
361      * returned in this enumeration; check for the default prefix
362      * using the {@link #getURI getURI} with an argument of "".</p>
363      *
364      * @return An enumeration of all prefixes declared in the
365      *         current context except for the empty (default)
366      *         prefix.
367      * @see #getDeclaredPrefixes
368      * @see #getURI
369      */
370     public Iterable<String> getPrefixes() {
371         return currentContext.getPrefixes();
372     }
373 
374     /**
375      * Return one of the prefixes mapped to a Namespace URI.
376      *
377      * <p>If more than one prefix is currently mapped to the same
378      * URI, this method will make an arbitrary selection; if you
379      * want all of the prefixes, use the {@link #getPrefixes}
380      * method instead.</p>
381      *
382      * <p><strong>Note:</strong> this will never return the empty (default) prefix;
383      * to check for a default prefix, use the {@link #getURI getURI}
384      * method with an argument of "".</p>
385      *
386      * @param uri The Namespace URI.
387      * @return One of the prefixes currently mapped to the URI supplied,
388      *         or null if none is mapped or if the URI is assigned to
389      *         the default Namespace.
390      * @see #getPrefixes(java.lang.String)
391      * @see #getURI
392      */
393     public String getPrefix(String uri) {
394         return currentContext.getPrefix(uri);
395     }
396 
397     /**
398      * Return an enumeration of all prefixes currently declared for a URI.
399      *
400      * <p>This method returns prefixes mapped to a specific Namespace
401      * URI.  The xml: prefix will be included.  If you want only one
402      * prefix that's mapped to the Namespace URI, and you don't care
403      * which one you get, use the {@link #getPrefix getPrefix}
404      *  method instead.</p>
405      *
406      * <p><strong>Note:</strong> the empty (default) prefix is <em>never</em> included
407      * in this enumeration; to check for the presence of a default
408      * Namespace, use the {@link #getURI getURI} method with an
409      * argument of "".</p>
410      *
411      * @param uri The Namespace URI.
412      * @return An enumeration of all prefixes declared in the
413      *         current context.
414      * @see #getPrefix
415      * @see #getDeclaredPrefixes
416      * @see #getURI
417      */
418     public Iterator getPrefixes(String uri) {
419         List prefixes = new ArrayList();
420         for (String prefix: getPrefixes()) {
421             if (uri.equals(getURI(prefix))) {
422                 prefixes.add(prefix);
423             }
424         }
425         return prefixes.iterator();
426     }
427 
428     /**
429      * Return an enumeration of all prefixes declared in this context.
430      *
431      * <p>The empty (default) prefix will be included in this
432      * enumeration; note that this behaviour differs from that of
433      * {@link #getPrefix} and {@link #getPrefixes}.</p>
434      *
435      * @return An enumeration of all prefixes declared in this
436      *         context.
437      * @see #getPrefixes
438      * @see #getURI
439      */
440     public Iterable<String> getDeclaredPrefixes() {
441         return currentContext.getDeclaredPrefixes();
442     }
443 
444     ////////////////////////////////////////////////////////////////////
445     // Internal state.
446     ////////////////////////////////////////////////////////////////////
447 
448     private Context contexts[];
449     private Context currentContext;
450     private int contextPos;
451 
452     ////////////////////////////////////////////////////////////////////
453     // Internal classes.
454     ////////////////////////////////////////////////////////////////////
455 
456     /**
457      * Internal class for a single Namespace context.
458      *
459      * <p>This module caches and reuses Namespace contexts, so the number
460      * allocated will be equal to the element depth of the document, not to the
461      * total number of elements (i.e. 5-10 rather than tens of thousands).</p>
462      */
463     final static class Context {
464 
465         /**
466          * Create the root-level Namespace context.
467          */
468         Context() {
469             copyTables();
470         }
471         // PGB May 6 2002 added copy constructor
472         Context(Context that, Context newParent) {
473             if (that == null) {
474                 copyTables();
475                 return;
476             }
477 
478             if (newParent != null && !that.tablesDirty) {
479                 prefixTable =
480                     that.prefixTable == that.parent.prefixTable
481                         ? newParent.prefixTable
482                         : (HashMap) that.prefixTable.clone();
483 
484                 uriTable =
485                     that.uriTable == that.parent.uriTable
486                         ? newParent.uriTable
487                         : (HashMap) that.uriTable.clone();
488                 elementNameTable =
489                     that.elementNameTable == that.parent.elementNameTable
490                         ? newParent.elementNameTable
491                         : (HashMap) that.elementNameTable.clone();
492                 attributeNameTable =
493                     that.attributeNameTable == that.parent.attributeNameTable
494                         ? newParent.attributeNameTable
495                         : (HashMap) that.attributeNameTable.clone();
496                 defaultNS =
497                     that.defaultNS == that.parent.defaultNS
498                         ? newParent.defaultNS
499                         : that.defaultNS;
500             } else {
501                 prefixTable = (HashMap) that.prefixTable.clone();
502                 uriTable = (HashMap) that.uriTable.clone();
503                 elementNameTable = (HashMap) that.elementNameTable.clone();
504                 attributeNameTable = (HashMap) that.attributeNameTable.clone();
505                 defaultNS = that.defaultNS;
506             }
507 
508             tablesDirty = that.tablesDirty;
509             parent = newParent;
510             declarations =
511                 that.declarations == null
512                     ? null
513                     : (ArrayList) that.declarations.clone();
514         }
515 
516         /**
517          * (Re)set the parent of this Namespace context.
518          *
519          * @param parent The parent Namespace context object.
520          */
521         void setParent(Context parent) {
522             this.parent = parent;
523             declarations = null;
524             prefixTable = parent.prefixTable;
525             uriTable = parent.uriTable;
526             elementNameTable = parent.elementNameTable;
527             attributeNameTable = parent.attributeNameTable;
528             defaultNS = parent.defaultNS;
529             tablesDirty = false;
530         }
531 
532         /**
533          * Declare a Namespace prefix for this context.
534          *
535          * @param prefix The prefix to declare.
536          * @param uri The associated Namespace URI.
537          * @see org.xml.sax.helpers.NamespaceSupport#declarePrefix
538          */
539         void declarePrefix(String prefix, String uri) {
540             // Lazy processing...
541             if (!tablesDirty) {
542                 copyTables();
543             }
544             if (declarations == null) {
545                 declarations = new ArrayList();
546             }
547 
548             prefix = prefix.intern();
549             uri = uri.intern();
550             if ("".equals(prefix)) {
551                 if ("".equals(uri)) {
552                     defaultNS = null;
553                 } else {
554                     defaultNS = uri;
555                 }
556             } else {
557                 prefixTable.put(prefix, uri);
558                 uriTable.put(uri, prefix); // may wipe out another prefix
559             }
560             declarations.add(prefix);
561         }
562 
563         /**
564          * Process a raw XML 1.0 name in this context.
565          *
566          * @param qName The raw XML 1.0 name.
567          * @param isAttribute true if this is an attribute name.
568          * @return An array of three strings containing the
569          *         URI part (or empty string), the local part,
570          *         and the raw name, all internalized, or null
571          *         if there is an undeclared prefix.
572          * @see org.xml.sax.helpers.NamespaceSupport#processName
573          */
574         String[] processName(String qName, boolean isAttribute) {
575             String name[];
576             Map table;
577 
578             // Select the appropriate table.
579             if (isAttribute) {
580                 table = elementNameTable;
581             } else {
582                 table = attributeNameTable;
583             }
584 
585             // Start by looking in the cache, and
586             // return immediately if the name
587             // is already known in this content
588             name = (String[]) table.get(qName);
589             if (name != null) {
590                 return name;
591             }
592 
593             // We haven't seen this name in this
594             // context before.
595             name = new String[3];
596             int index = qName.indexOf(':');
597 
598             // No prefix.
599             if (index == -1) {
600                 if (isAttribute || defaultNS == null) {
601                     name[0] = "";
602                 } else {
603                     name[0] = defaultNS;
604                 }
605                 name[1] = qName.intern();
606                 name[2] = name[1];
607             }
608 
609             // Prefix
610             else {
611                 String prefix = qName.substring(0, index);
612                 String local = qName.substring(index + 1);
613                 String uri;
614                 if ("".equals(prefix)) {
615                     uri = defaultNS;
616                 } else {
617                     uri = (String) prefixTable.get(prefix);
618                 }
619                 if (uri == null) {
620                     return null;
621                 }
622                 name[0] = uri;
623                 name[1] = local.intern();
624                 name[2] = qName.intern();
625             }
626 
627             // Save in the cache for future use.
628             table.put(name[2], name);
629             tablesDirty = true;
630             return name;
631         }
632 
633         /**
634          * Look up the URI associated with a prefix in this context.
635          *
636          * @param prefix The prefix to look up.
637          * @return The associated Namespace URI, or null if none is
638          *         declared.
639          * @see org.xml.sax.helpers.NamespaceSupport#getURI
640          */
641         String getURI(String prefix) {
642             if ("".equals(prefix)) {
643                 return defaultNS;
644             } else if (prefixTable == null) {
645                 return null;
646             } else {
647                 return (String) prefixTable.get(prefix);
648             }
649         }
650 
651         /**
652          * Look up one of the prefixes associated with a URI in this context.
653          *
654          * <p>Since many prefixes may be mapped to the same URI,
655          * the return value may be unreliable.</p>
656          *
657          * @param uri The URI to look up.
658          * @return The associated prefix, or null if none is declared.
659          * @see org.xml.sax.helpers.NamespaceSupport#getPrefix
660          */
661         String getPrefix(String uri) {
662             if (uriTable == null) {
663                 return null;
664             } else {
665                 return (String) uriTable.get(uri);
666             }
667         }
668 
669         /**
670          * Return an enumeration of prefixes declared in this context.
671          *
672          * @return An enumeration of prefixes (possibly empty).
673          * @see org.xml.sax.helpers.NamespaceSupport#getDeclaredPrefixes
674          */
675         Iterable<String> getDeclaredPrefixes() {
676             if (declarations == null) {
677                 return EMPTY_ENUMERATION;
678             } else {
679                 return declarations;
680             }
681         }
682 
683         /**
684          * Return an enumeration of all prefixes currently in force.
685          *
686          * <p>The default prefix, if in force, is <em>not</em>
687          * returned, and will have to be checked for separately.</p>
688          *
689          * @return An enumeration of prefixes (never empty).
690          * @see org.xml.sax.helpers.NamespaceSupport#getPrefixes
691          */
692         Iterable<String> getPrefixes() {
693             if (prefixTable == null) {
694                 return EMPTY_ENUMERATION;
695             } else {
696                 return prefixTable.keySet();
697             }
698         }
699 
700         ////////////////////////////////////////////////////////////////
701         // Internal methods.
702         ////////////////////////////////////////////////////////////////
703 
704         /**
705          * Copy on write for the internal tables in this context.
706          *
707          * <p>This class is optimized for the normal case where most
708          * elements do not contain Namespace declarations.</p>
709          */
710         private void copyTables() {
711             if (prefixTable != null) {
712                 prefixTable = (HashMap) prefixTable.clone();
713             } else {
714                 prefixTable = new HashMap();
715             }
716             if (uriTable != null) {
717                 uriTable = (HashMap) uriTable.clone();
718             } else {
719                 uriTable = new HashMap();
720             }
721             elementNameTable = new HashMap();
722             attributeNameTable = new HashMap();
723             tablesDirty = true;
724         }
725 
726         ////////////////////////////////////////////////////////////////
727         // Protected state.
728         ////////////////////////////////////////////////////////////////
729 
730         HashMap prefixTable;
731         HashMap uriTable;
732         // PBG May 6 2002 changed these two from Map to HashMap
733         HashMap elementNameTable;
734         HashMap attributeNameTable;
735         String defaultNS = null;
736 
737         ////////////////////////////////////////////////////////////////
738         // Internal state.
739         ////////////////////////////////////////////////////////////////
740 
741         // PBG May 6 2002 changed this from List to ArrayList
742         private ArrayList declarations = null;
743         private boolean tablesDirty = false;
744         private Context parent = null;
745     }
746 }