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Java > Open Source Codes > jdiff > CommentsHandler


1 package jdiff;
2
3 import java.io.*;
4 import java.util.*;
5
6 /* For SAX XML parsing */
7 import org.xml.sax.Attributes JavaDoc;
8 import org.xml.sax.SAXException JavaDoc;
9 import org.xml.sax.SAXParseException JavaDoc;
10 import org.xml.sax.XMLReader JavaDoc;
11 import org.xml.sax.helpers.DefaultHandler JavaDoc;
12
13 /**
14  * Handle the parsing of an XML file and the generation of a Comments object.
15  *
16  * All HTML written for the comments sections in the report must
17  * use tags such as <p/> rather than just <p>, since the XML
18  * parser used requires that or matching end elements.
19  *
20  * From http://www.w3.org/TR/2000/REC-xhtml1-20000126:
21  * "Empty elements must either have an end tag or the start tag must end with /<".
22  *
23  * See the file LICENSE.txt for copyright details.
24  * @author Matthew Doar, doar@pobox.com
25  */
26 class CommentsHandler extends DefaultHandler JavaDoc {
27
28     /** The Comments object which is populated from the XML file. */
29     public Comments comments_ = null;
30
31     /** The current SingleComment object being populated. */
32     private List currSingleComment_ = null; // SingleComment[]
33
34     /** Set if in text. */
35     private boolean inText = false;
36
37     /** The current text which is being assembled from chunks. */
38     private String JavaDoc currentText = null;
39     
40     /** The stack of SingleComments still waiting for comment text. */
41     private LinkedList tagStack = null;
42
43     /** Default constructor. */
44     public CommentsHandler(Comments comments) {
45         comments_ = comments;
46         tagStack = new LinkedList();
47     }
48
49     public void startDocument() {
50     }
51     
52     public void endDocument() {
53         if (trace)
54             comments_.dump();
55     }
56
57     public void startElement(java.lang.String JavaDoc uri, java.lang.String JavaDoc localName,
58                              java.lang.String JavaDoc qName, Attributes JavaDoc attributes) {
59     // The change to JAXP compliance produced this change.
60 if (localName.equals(""))
61         localName = qName;
62         if (localName.compareTo("comments") == 0) {
63             String JavaDoc commentsName = attributes.getValue("name");
64             String JavaDoc version = attributes.getValue("jdversion"); // Not used yet
65 if (commentsName == null) {
66                 System.out.println("Error: no identifier found in the comments XML file.");
67                 System.exit(3);
68             }
69             // Check the given names against the names of the APIs
70 int idx1 = JDiff.oldFileName.lastIndexOf('.');
71             int idx2 = JDiff.newFileName.lastIndexOf('.');
72             String JavaDoc filename2 = JDiff.oldFileName.substring(0, idx1) +
73                 "_to_" + JDiff.newFileName.substring(0, idx2);
74             if (filename2.compareTo(commentsName) != 0) {
75                 System.out.println("Warning: API identifier in the comments XML file (" + filename2 + ") differs from the name of the file.");
76             }
77         } else if (localName.compareTo("comment") == 0) {
78             currSingleComment_ = new ArrayList(); // SingleComment[];
79 } else if (localName.compareTo("identifier") == 0) {
80             // May have multiple identifiers for one comment's text
81 String JavaDoc id = attributes.getValue("id");
82             SingleComment newComment = new SingleComment(id, null);
83             // Store it here until we can add text to it
84 currSingleComment_.add(newComment);
85         } else if (localName.compareTo("text") == 0) {
86             inText = true;
87             currentText = null;
88         } else {
89             if (inText) {
90                 // Start of an element, probably an HTML element
91 addStartTagToText(localName, attributes);
92             } else {
93                 System.out.println("Error: unknown element type: " + localName);
94                 System.exit(-1);
95             }
96         }
97     }
98     
99     public void endElement(java.lang.String JavaDoc uri, java.lang.String JavaDoc localName,
100                            java.lang.String JavaDoc qName) {
101     if (localName.equals(""))
102         localName = qName;
103         if (localName.compareTo("text") == 0) {
104             inText = false;
105             addTextToComments();
106         } else if (inText) {
107             addEndTagToText(localName);
108         }
109
110     }
111     
112     /** Deal with a chunk of text. The text may come in multiple chunks. */
113     public void characters(char[] ch, int start, int length) {
114         if (inText) {
115             String JavaDoc chunk = new String JavaDoc(ch, start, length);
116             if (currentText == null)
117                 currentText = chunk;
118             else
119                 currentText += chunk;
120         }
121     }
122
123     /**
124      * Trim the current text, check it is a sentence and add it to all
125      * the comments which are waiting for it.
126      */
127     public void addTextToComments() {
128         // Eliminate any whitespace at each end of the text.
129 currentText = currentText.trim();
130         // Check that it is a sentence
131 if (!currentText.endsWith(".") &&
132             !currentText.endsWith("?") &&
133             !currentText.endsWith("!") &&
134             currentText.compareTo(Comments.placeHolderText) != 0) {
135             System.out.println("Warning: text of comment does not end in a period: " + currentText);
136         }
137         // Add this comment to all the SingleComments waiting for it
138 Iterator iter = currSingleComment_.iterator();
139         while (iter.hasNext()) {
140             SingleComment currComment = (SingleComment)(iter.next());
141             if (currComment.text_ == null)
142                 currComment.text_ = currentText;
143             else
144                 currComment.text_ += currentText;
145             comments_.addComment(currComment);
146         }
147     }
148
149     /**
150      * Add the start tag to the current comment text.
151      */
152     public void addStartTagToText(String JavaDoc localName, Attributes JavaDoc attributes) {
153         // Need to insert the HTML tag into the current text
154 String JavaDoc currentHTMLTag = localName;
155         // Save the tag in a stack
156 tagStack.add(currentHTMLTag);
157         String JavaDoc tag = "<" + currentHTMLTag;
158         // Now add all the attributes into the current text
159 int len = attributes.getLength();
160         for (int i = 0; i < len; i++) {
161             String JavaDoc name = attributes.getLocalName(i);
162             String JavaDoc value = attributes.getValue(i);
163             tag += " " + name + "=\"" + value+ "\"";
164         }
165
166         // End the tag
167 if (Comments.isMinimizedTag(currentHTMLTag)) {
168             tag += "/>";
169         } else {
170             tag += ">";
171         }
172         // Now insert the HTML tag into the current text
173 if (currentText == null)
174             currentText = tag;
175         else
176             currentText += tag;
177     }
178
179     /**
180      * Add the end tag to the current comment text.
181      */
182     public void addEndTagToText(String JavaDoc localName) {
183         // Close the current HTML tag
184 String JavaDoc currentHTMLTag = (String JavaDoc)(tagStack.removeLast());
185         if (!Comments.isMinimizedTag(currentHTMLTag))
186             currentText += "</" + currentHTMLTag + ">";
187     }
188
189     public void warning(SAXParseException JavaDoc e) {
190         System.out.println("Warning (" + e.getLineNumber() + "): parsing XML comments file:" + e);
191         e.printStackTrace();
192     }
193
194     public void error(SAXParseException JavaDoc e) {
195         System.out.println("Error (" + e.getLineNumber() + "): parsing XML comments file:" + e);
196         e.printStackTrace();
197         System.exit(1);
198     }
199     
200     public void fatalError(SAXParseException JavaDoc e) {
201         System.out.println("Fatal Error (" + e.getLineNumber() + "): parsing XML comments file:" + e);
202         e.printStackTrace();
203         System.exit(1);
204     }
205
206     /** Set to enable increased logging verbosity for debugging. */
207     private static final boolean trace = false;
208
209 }
210
211
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