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Java > Open Source Codes > org > apache > jetspeed > util > SAXPIFilter


1 /*
2  * Copyright 2000-2004 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 package org.apache.jetspeed.util;
18
19 //standard java stuff
20 import java.io.InputStream JavaDoc;
21 import java.io.PrintWriter JavaDoc;
22 import java.io.Reader JavaDoc;
23 import java.io.UnsupportedEncodingException JavaDoc;
24 import java.util.Vector JavaDoc;
25
26 // SAX classes
27 import org.xml.sax.AttributeList JavaDoc;
28 import org.xml.sax.HandlerBase JavaDoc;
29 import org.xml.sax.InputSource JavaDoc;
30 import org.xml.sax.Parser JavaDoc;
31 import org.xml.sax.SAXException JavaDoc;
32 import org.xml.sax.SAXParseException JavaDoc;
33 import org.xml.sax.helpers.ParserFactory JavaDoc;
34
35 // Jetspeed classes
36 import org.apache.jetspeed.services.logging.JetspeedLogFactoryService;
37 import org.apache.jetspeed.services.logging.JetspeedLogger;
38
39 /**
40 This class is used to either strip and/or insert PIs in a XML document.
41 It uses SAX-1 API and outputs text to an
42 output stream.
43 WARNING: This behavior will be modified in the future.
44
45 @author <A HREF="mailto:raphael@apache.org">Raphaël Luta</A>
46 @version $Id: SAXPIFilter.java,v 1.8 2004/02/23 03:23:42 jford Exp $
47 */
48 public class SAXPIFilter extends HandlerBase JavaDoc
49 {
50     /**
51      * Static initialization of the logger for this class
52      */
53     private static final JetspeedLogger logger = JetspeedLogFactoryService.getLogger(SAXPIFilter.class.getName());
54     
55     private static final String JavaDoc DEFAULT_PARSER_NAME = "org.apache.xerces.parsers.SAXParser";
56
57     protected PrintWriter JavaDoc out=new PrintWriter JavaDoc(System.out);
58
59     private String JavaDoc pi;
60
61     private boolean stripExistingPI;
62
63     private Vector JavaDoc pis = new Vector JavaDoc();
64     
65     /**
66     Creates of simple parser which outputs its document to the PrintWriter passed
67     as arguments.
68     In this mode the parser may be used as a simple well-formedness checker.
69
70     @param outPW the printWriter where to output parsed data
71     */
72     public SAXPIFilter(PrintWriter JavaDoc outPW) throws UnsupportedEncodingException JavaDoc {
73         this(outPW,false,null);
74     }
75
76     /**
77     In this mode the parser may be used as a simple well-formedness checker or a PI
78     stripper.
79
80     @param outPW the printWriter where to output parsed data
81     @param strip configure the parser to strip PIs if strip is true
82     */
83     public SAXPIFilter(PrintWriter JavaDoc outPW, boolean strip) throws UnsupportedEncodingException JavaDoc {
84         this( outPW, strip, null );
85     }
86
87     /**
88     In this mode the parser can strip existing PIs and insert new ones just after
89     the document declaration
90
91     @param outPW the printWriter where to output parsed data
92     @param strip configure the parser to strip PIs if strip is true
93     @param PI string reprensenting the PI to be output after the document declaration
94     */
95     public SAXPIFilter(PrintWriter JavaDoc outPW, boolean strip, String JavaDoc PI) throws UnsupportedEncodingException JavaDoc {
96         this.out=outPW;
97         this.stripExistingPI=strip;
98         this.pi=PI;
99     }
100
101     /**
102     Get all permitted processing instructions
103     */
104     public String JavaDoc[] getProcessingInstructions() {
105         
106         String JavaDoc[] ins = new String JavaDoc[ pis.size() ];
107         pis.copyInto( ins );
108         return ins;
109         
110     }
111     
112     public void addProcessingInstruction(String JavaDoc pi) {
113         this.pis.addElement( pi );
114     }
115
116
117     /**
118     Parse and output the content of the URL given as parameter.
119
120     @param uri URL where to fetch the document to be parsed
121     */
122     public void print(String JavaDoc uri) {
123
124         try {
125             HandlerBase JavaDoc handler = this;
126
127             Parser JavaDoc parser = ParserFactory.makeParser(DEFAULT_PARSER_NAME);
128             parser.setDocumentHandler(handler);
129             parser.setErrorHandler(handler);
130             parser.parse(uri);
131         }
132         catch (Exception JavaDoc e) {
133             logger.error("Exception", e);
134         }
135
136     }
137
138     /**
139     Parse and output the content of the stream
140
141     @param in a content InputStream
142     */
143     public void print(InputStream JavaDoc in) {
144
145         try {
146             HandlerBase JavaDoc handler = this;
147
148             Parser JavaDoc parser = ParserFactory.makeParser(DEFAULT_PARSER_NAME);
149             parser.setDocumentHandler(handler);
150             parser.setErrorHandler(handler);
151             parser.parse(new InputSource JavaDoc(in));
152         }
153         catch (Exception JavaDoc e) {
154             logger.error("Exception", e);
155         }
156
157     }
158
159     /**
160     Parse and output the content of the reader
161
162     @param in a content Reader
163     */
164     public void print(Reader JavaDoc in) {
165
166         try {
167             HandlerBase JavaDoc handler = this;
168
169             Parser JavaDoc parser = ParserFactory.makeParser(DEFAULT_PARSER_NAME);
170             parser.setDocumentHandler(handler);
171             parser.setErrorHandler(handler);
172             parser.parse(new InputSource JavaDoc(in));
173         }
174         catch (Exception JavaDoc e) {
175             logger.error("Exception", e);
176         }
177
178     }
179
180     /**
181     SAX Handler implementation
182     */
183     public void processingInstruction(String JavaDoc target, String JavaDoc data) {
184
185         
186         if ( ! stripExistingPI ) {
187             out.print( makeSAXPI( target, data ) );
188         } else {
189             //cocoon-process
190 //if your original XML document has cocoon tags leave them in.
191
192             //add exceptable processing instructions here.
193 if ( target.equals("cocoon-process") ) {
194                 
195                 this.addProcessingInstruction( makeSAXPI( target, data ) );
196
197            }
198             
199         }
200
201     }
202
203     private String JavaDoc makeSAXPI( String JavaDoc target, String JavaDoc data ) {
204
205         StringBuffer JavaDoc buffer = new StringBuffer JavaDoc();
206         buffer.append("<?");
207         buffer.append( target );
208         if (data != null && data.length() > 0) {
209             buffer.append(' ');
210             buffer.append(data);
211         }
212         buffer.append("?>");
213         
214         return buffer.toString();
215     }
216     
217    
218
219     /**
220     SAX Handler implementation
221     */
222     public void startDocument() {
223
224         if ( pi != null ) {
225             out.print( pi );
226         }
227
228     }
229
230     /**
231     SAX Handler implementation
232     */
233     public void startElement(String JavaDoc name, AttributeList JavaDoc attrs) {
234
235         out.print('<');
236         out.print(name);
237         if (attrs != null) {
238             int len = attrs.getLength();
239             for (int i = 0; i < len; i++) {
240                 out.print(' ');
241                 out.print(attrs.getName(i));
242                 out.print("=\"");
243                 out.print(normalize(attrs.getValue(i)));
244                 out.print('"');
245             }
246         }
247         out.print('>');
248
249     }
250
251     /**
252     SAX Handler implementation
253     */
254     public void characters(char ch[], int start, int length) {
255
256         out.print(normalize(new String JavaDoc(ch, start, length)));
257
258     }
259
260     /**
261     SAX Handler implementation
262     */
263     public void ignorableWhitespace(char ch[], int start, int length) {
264
265         characters(ch, start, length);
266
267     }
268
269     /**
270     SAX Handler implementation
271     */
272     public void endElement(String JavaDoc name) {
273
274         out.print("</");
275         out.print(name);
276         out.print('>');
277
278     }
279
280     /**
281     SAX Handler implementation
282     */
283     public void endDocument() {
284
285         out.flush();
286
287     }
288
289     /**
290     SAX Handler implementation
291     */
292     public void warning(SAXParseException JavaDoc ex) {
293         System.err.println("[Warning] "+
294                            getLocationString(ex)+": "+
295                            ex.getMessage());
296     }
297
298     /**
299     SAX Handler implementation
300     */
301     public void error(SAXParseException JavaDoc ex) {
302         System.err.println("[Error] "+
303                            getLocationString(ex)+": "+
304                            ex.getMessage());
305     }
306
307     /**
308     SAX Handler implementation
309     */
310     public void fatalError(SAXParseException JavaDoc ex) throws SAXException JavaDoc {
311         System.err.println("[Fatal Error] "+
312                            getLocationString(ex)+": "+
313                            ex.getMessage());
314         throw ex;
315     }
316
317     /**
318     Retrieves the error location in the input stream
319     */
320     private String JavaDoc getLocationString(SAXParseException JavaDoc ex) {
321         StringBuffer JavaDoc str = new StringBuffer JavaDoc();
322
323         String JavaDoc systemId = ex.getSystemId();
324         if (systemId != null) {
325             int index = systemId.lastIndexOf('/');
326             if (index != -1)
327                 systemId = systemId.substring(index + 1);
328             str.append(systemId);
329         }
330         str.append(':');
331         str.append(ex.getLineNumber());
332         str.append(':');
333         str.append(ex.getColumnNumber());
334
335         return str.toString();
336
337     }
338
339     /**
340     Escapes characters data
341     */
342     protected String JavaDoc normalize(String JavaDoc s) {
343         StringBuffer JavaDoc str = new StringBuffer JavaDoc();
344
345         int len = (s != null) ? s.length() : 0;
346         for (int i = 0; i < len; i++) {
347             char ch = s.charAt(i);
348             switch (ch) {
349                 case '<': {
350                     str.append("&lt;");
351                     break;
352                 }
353                 case '>': {
354                     str.append("&gt;");
355                     break;
356                 }
357                 case '&': {
358                     str.append("&amp;");
359                     break;
360                 }
361                 case '"': {
362                     str.append("&quot;");
363                     break;
364                 }
365                 default: {
366                     str.append(ch);
367                 }
368             }
369         }
370
371         return str.toString();
372
373     }
374
375 }
376
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