StatefullSAXHandler


1   package org.sapia.util.xml.parser;
2   
3   
4   // Imports of David Meggison's SAX classes
5   // ---------------------------------------
6   import org.xml.sax.Attributes  ;
7   import org.xml.sax.InputSource  ;
8   import org.xml.sax.Locator  ;
9   import org.xml.sax.SAXException  ;
10  import org.xml.sax.SAXParseException  ;
11  import org.xml.sax.helpers.DefaultHandler  ;
12  
13  
14  // Import of Apache's Log4j classes
15  // --------------------------------
16  //import org.apache.log4j.Logger;
17  
18  /**
19   * The <CODE>StatefullSAXHandler</CODE> class is a SAX event handler. When one of is callback
20   * methods is called, it delegates the call to the current handler object; that current
21   * handler is refered as the "current state" of the handler. It accesses the <CODE>HandlerStateIF</CODE>
22   * instance by using a <CODE>HandlerContextIF</CODE>. That context is passed at creation
23   * and contains the stack of all the handlers as well as their result objects.
24   *
25   * @see HandlerContextIF
26   * @see HandlerStateIF
27   * @author Jean-Cedric Desrochers
28   * <dl>
29   * <dt><b>Copyright:</b><dd>Copyright &#169; 2002-2003 <a HREF="http://www.sapia-oss.org">Sapia Open Source Software</a>. All Rights Reserved.</dd></dt>
30   * <dt><b>License:</b><dd>Read the license.txt file of the jar or visit the
31   *        <a HREF="http://www.sapia-oss.org/license.html">license page</a> at the Sapia OSS web site</dd></dt>
32   * </dl>
33   */
34  public class StatefullSAXHandler extends DefaultHandler   {
35    /////////////////////////////////////////////////////////////////////////////////////////
36    //////////////////////////////////  CLASS ATTRIBUTES  ///////////////////////////////////
37    /////////////////////////////////////////////////////////////////////////////////////////
38  
39    /** Defines the logger instance for this class. */
40  
41    //private static Logger _theLogger = Logger.getLogger(StatefullSAXHandler.class);
42    /////////////////////////////////////////////////////////////////////////////////////////
43    /////////////////////////////////  INSTANCE ATTRIBUTES  /////////////////////////////////
44    /////////////////////////////////////////////////////////////////////////////////////////
45  
46    /** The context of this handler. */
47    private HandlerContextIF _theContext;
48  
49    /** The locator of this parser. */
50    private Locator   _theLocator;
51  
52    /////////////////////////////////////////////////////////////////////////////////////////
53    ////////////////////////////////////  CONSTRUCTORS  /////////////////////////////////////
54    /////////////////////////////////////////////////////////////////////////////////////////
55  
56    /**
57     * Creates a new StatefullSAXHandler instance with the argument passed in.
58     *
59     * @param aContext The handler context.
60     */
61    public StatefullSAXHandler(HandlerContextIF aHandlerContext) {
62      _theContext = aHandlerContext;
63    }
64  
65    /////////////////////////////////////////////////////////////////////////////////////////
66    //////////////////////////////////  ACCESSOR METHODS  ///////////////////////////////////
67    /////////////////////////////////////////////////////////////////////////////////////////
68  
69    /**
70     * Returns a textual description of the current document position with the following
71     * format: "<CODE>Document position: line number=x  column number=y</CODE>".
72     *
73     * @return A textual description of the current document position.
74     */
75    public String   getDocumentPosition() {
76      StringBuffer   aBuffer = new StringBuffer  ();
77      aBuffer.append("Document position: line number=")
78             .append(_theLocator.getLineNumber()).append("  column number=")
79             .append(_theLocator.getColumnNumber());
80  
81      return aBuffer.toString();
82    }
83  
84    /////////////////////////////////////////////////////////////////////////////////////////
85    //////////////////////////////////  OVERRIDEN METHODS  //////////////////////////////////
86    /////////////////////////////////////////////////////////////////////////////////////////
87  
88    /**
89     * Overrides the default implementation of the ContentHandler interface and allow the
90     * application to resolve external entities.
91     *
92     * @param aPublicID The public identifier of the external entity being referenced, or null if none was supplied.
93     * @param aSystemID The system identifier of the external entity being referenced.
94     */
95    public InputSource   resolveEntity(String   aPublicID, String   aSystemID)
96      throws SAXException   {
97      // Logging a debug message
98  
99      /*if (_theLogger.isDebugEnabled()) {
100       StringBuffer aBuffer = new StringBuffer("Method resolveEntity() is beign called with");
101       aBuffer.append(" publicID=").append(aPublicID).
102               append(" systemID=").append(aSystemID);
103       _theLogger.debug(aBuffer.toString());
104     }*/
105     return null;
106   }
107 
108   /**
109    * Overrides the default implementation of the ContentHandler interface and receive
110    * notification of a notation declaration event.
111    *
112    * @param aName The notation name.
113    * @param aPublicId The notation's public identifier, or null if none was given.
114    * @param aSystemId The notation's system identifier, or null if none was given.
115    */
116   public void notationDecl(String   aName, String   aPublicID, String   aSystemID)
117     throws SAXException   {
118     // Logging a debug message
119 
120     /*if (_theLogger.isDebugEnabled()) {
121       StringBuffer aBuffer = new StringBuffer("Method notationDecl() is beign called with");
122       aBuffer.append(" name=").append(aName).
123               append(" publicID=").append(aPublicID).
124               append(" systemID=").append(aSystemID);
125       _theLogger.debug(aBuffer.toString());
126     }*/
127   }
128 
129   /**
130    * Overrides the default implementation of the ContentHandler interface and receive
131    * notification of an unparsed entity declaration event.
132    *
133    * @param aName The unparsed entity name.
134    * @param aPublicId The notation's public identifier, or null if none was given.
135    * @param aSystemId The notation's system identifier, or null if none was given.
136    * @param aNotationName The name of the associated notation.
137    */
138   public void unparsedEntityDecl(String   aName, String   aPublicID,
139     String   aSystemID, String   aNotationName) throws SAXException   {
140     // Logging a debug message
141 
142     /*if (_theLogger.isDebugEnabled()) {
143       StringBuffer aBuffer = new StringBuffer("Method unparsedEntityDecl() is beign called with");
144       aBuffer.append(" name=").append(aName).
145               append(" publicID=").append(aPublicID).
146               append(" systemID=").append(aSystemID).
147               append(" notationName=").append(aNotationName);
148       _theLogger.debug(aBuffer.toString());
149     }*/
150   }
151 
152   /**
153    * Overrides the default implementation of the ContentHandler interface and receives
154    * the Locator object for document positions.
155    *
156    * @param aLocator A locator for all SAX document events.
157    * @see org.xml.sax.ContentHandler#setDocumentLocator
158    */
159   public void setDocumentLocator(Locator   aLocator) {
160     _theLocator = aLocator;
161   }
162 
163   /**
164    * Overrides the default implementation of the ContentHandler interface and forwards the
165    * notification of the beginning of the document to the current HandleStateIF object of
166    * this parser.
167    *
168    * @exception SAXException Any SAX exception, possibly wrapping another exception.
169    * @see org.xml.sax.ContentHandler#startDocument
170    */
171   public void startDocument() throws SAXException   {
172     // Logging a debug message
173 
174     /*if (_theLogger.isDebugEnabled()) {
175       _theLogger.debug("Method startDocument() is beign called");
176     }*/
177   }
178 
179   /**
180    * Overrides the default implementation of the ContentHandler interface and forwards the
181    * notification of the end of the document to the current HandleStateIF object of
182    * this parser.
183    *
184    * @exception SAXException Any SAX exception, possibly wrapping another exception.
185    * @see org.xml.sax.ContentHandler#endDocument
186    */
187   public void endDocument() throws SAXException   {
188     // Logging a debug message
189 
190     /*if (_theLogger.isDebugEnabled()) {
191       _theLogger.debug("Method endDocument() is beign called");
192     }*/
193   }
194 
195   /**
196    * Overrides the default implementation of the ContentHandler interface and sets the
197    * namespace URI passed in as the current mapping for the given prefix.
198    *
199    * @param aPrefix The Namespace prefix being declared.
200    * @param anUri The Namespace URI mapped to the prefix.
201    * @exception SAXException Any SAX exception, possibly wrapping another exception.
202    */
203   public void startPrefixMapping(String   aPrefix, String   anUri)
204     throws SAXException   {
205     // Logging an info message
206 
207     /*if (_theLogger.isDebugEnabled()) {
208       _theLogger.debug("Starts mapping of the prefix [" + aPrefix +
209               "] to the namespace URI [" + anUri + "].");
210     }*/
211     try {
212       _theContext.startPrefixMapping(aPrefix, anUri);
213     } catch (RuntimeException   re) {
214       final String   aMessage = "RuntimeException caugh in method startPrefixMapping().";
215 
216       //_theLogger.error(aMessage, re);
217       throw new SAXException  (aMessage, re);
218     }
219   }
220 
221   /**
222    * Overrides the default implementation of the ContentHandler interface and removes
223    * the current mapping of the prefix passed in.
224    *
225    * @param aPrefix The Namespace prefix being declared.
226    * @exception SAXException Any SAX exception, possibly wrapping another exception.
227    * @see org.xml.sax.ContentHandler#endPrefixMapping
228    */
229   public void endPrefixMapping(String   aPrefix) throws SAXException   {
230     // Logging an info message
231 
232     /*if (_theLogger.isDebugEnabled()) {
233       _theLogger.debug("Ends mapping of the prefix [" + aPrefix + "].");
234     }*/
235     try {
236       _theContext.endPrefixMapping(aPrefix);
237     } catch (RuntimeException   re) {
238       final String   aMessage = "RuntimeException caugh in method endPrefixMapping().";
239 
240       //_theLogger.error(aMessage, re);
241       throw new SAXException  (aMessage, re);
242     }
243   }
244 
245   /**
246    * Overrides the default implementation of the ContentHandler interface and forwards
247    * the notification of the the start of an element to the current HandleStateIF
248    * object of this parser.
249    *
250    * @param anUri The namespace URI associated with the element
251    * @param aLocalName The element type local name.
252    * @param aQualifiedName The element type qualified name.
253    * @param someAttributes The specified or defaulted attributes.
254    * @exception SAXException Any SAX exception, possibly wrapping another exception.
255    * @see org.xml.sax.ContentHandler#startElement
256    */
257   public void startElement(String   anUri, String   aLocalName,
258     String   aQualifiedName, Attributes   someAttributes) throws SAXException   {
259     try {
260       _theContext.getCurrentState().startElement(_theContext, anUri,
261         aLocalName, aQualifiedName, someAttributes);
262     } catch (RuntimeException   re) {
263       final String   aMessage = "RuntimeException caugh in method startElement().";
264 
265       //_theLogger.error(aMessage, re);
266       throw new SAXException  (aMessage, re);
267     }
268   }
269 
270   /**
271    * Overrides the default implementation of the ContentHandler interface and forwards
272    * the notification of the the end of an element to the current HandleStateIF
273    * object of this parser.
274    *
275    * @param anUri The namespace URI associated with the element
276    * @param aLocalName The element type local name.
277    * @param aQualifiedName The element type qualified name.
278    * @param someAttributes The specified or defaulted attributes.
279    * @exception SAXException Any SAX exception, possibly wrapping another exception.
280    * @see org.xml.sax.ContentHandler#endElement
281    */
282   public void endElement(String   anUri, String   aLocalName, String   aQualifiedName)
283     throws SAXException   {
284     try {
285       _theContext.getCurrentState().endElement(_theContext, anUri, aLocalName,
286         aQualifiedName);
287     } catch (RuntimeException   re) {
288       final String   aMessage = "RuntimeException caugh in method endElement().";
289 
290       //_theLogger.error(aMessage, re);
291       throw new SAXException  (aMessage, re);
292     }
293   }
294 
295   /**
296    * Overrides the default implementation of the ContentHandler interface and forwards
297    * the notification of character data inside an element to the current HandleStateIF
298    * object of this parser.
299    *
300    * @param someChars The characters.
301    * @param anOffset The start position in the character array.
302    * @param aLength The number of characters to use from the character array.
303    * @exception SAXException Any SAX exception, possibly wrapping another exception.
304    * @see org.xml.sax.ContentHandler#characters
305    */
306   public void characters(char[] someChars, int anOffset, int aLength)
307     throws SAXException   {
308     try {
309       _theContext.getCurrentState().characters(_theContext, someChars,
310         anOffset, aLength);
311     } catch (RuntimeException   re) {
312       final String   aMessage = "RuntimeException caugh in method character().";
313 
314       //_theLogger.error(aMessage, re);
315       throw new SAXException  (aMessage, re);
316     }
317   }
318 
319   /**
320    * Overrides the default implementation of the ContentHandler interface and forwards
321    * the notification of ignorable whitespace in element content to the current
322    * HandleStateIF object of this parser.
323    *
324    * @param someChars The whitespace characters.
325    * @param anOffset The start position in the character array.
326    * @param aLength The number of characters to use from the character array.
327    * @exception SAXException Any SAX exception, possibly wrapping another exception.
328    * @see org.xml.sax.ContentHandler#ignorableWhitespace
329    */
330   public void ignorableWhitespace(char[] someChars, int anOffset, int aLength)
331     throws SAXException   {
332     try {
333       _theContext.getCurrentState().ignorableWhitespace(_theContext, someChars,
334         anOffset, aLength);
335     } catch (RuntimeException   re) {
336       final String   aMessage = "RuntimeException caugh in method ignorableWhitespace().";
337 
338       //_theLogger.error(aMessage, re);
339       throw new SAXException  (aMessage, re);
340     }
341   }
342 
343   /**
344    * Overrides the default implementation of the ErrorHandler interface logs a warning
345    * message of the warning and the current document position of the parser.
346    *
347    * @param aWarning The warning information encoded as an exception.
348    * @exception SAXException Any SAX exception, possibly wrapping another exception.
349    * @see org.xml.sax.ErrorHandler#warning
350    */
351   public void warning(SAXParseException   aWarning) throws SAXException   {
352     //_theLogger.warn(getDocumentPosition(), aWarning);
353   }
354 
355   /**
356    * Overrides the default implementation of the ErrorHandler interface logs a critical
357    * message of the error and the current document position of the parser.
358    *
359    * @param anError The error information encoded as an exception.
360    * @exception SAXException Any SAX exception, possibly wrapping another exception.
361    * @see org.xml.sax.ErrorHandler#warning
362    * @see org.xml.sax.SAXParseException
363    */
364   public void error(SAXParseException   anError) throws SAXException   {
365     //_theLogger.error(getDocumentPosition(), anError);
366   }
367 
368   /**
369    * Overrides the default implementation of the ErrorHandler interface logs an error
370    * message of the fatal error and the current document position of the parser.
371    *
372    * @param aFatalError The fatal error information encoded as an exception.
373    * @exception SAXException Any SAX exception, possibly wrapping another exception.
374    * @see org.xml.sax.ErrorHandler#fatalError
375    * @see org.xml.sax.SAXParseException
376    */
377   public void fatalError(SAXParseException   aFatalError)
378     throws SAXException   {
379     //_theLogger.error(getDocumentPosition(), aFatalError);
380     throw aFatalError;
381   }
382 }
383
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags