001 /***********************************************************************************************
002 * Tekijä: Jukka Salminen
003 * Opiskelijanumero: i79947
004 * Email: jukka.salminen@uwasa.fi
005 * Tekoaika: 23.9.2002
006 * Kurssi/vuosi: Ohjelmoinnin jatkokurssi/kevät 2002
007 * Työn tunnus: Harjoitustyö: Taulukkoeditori web-sivulle
008 ***********************************************************************************************
009 * QDParser-luokka
010 * ===============
011 * Lähde: www.javaworld.com
012 *http://www.javaworld.com/javaworld/javatips/jw-javatip128.html
013 * Quick and Dirty xml parser. This parser is, like the SAX parser,
014 * an event based parser, but with much less functionality. */
015 package jsxml.qdxml;
016 import java.io.*;
017 import java.util.*;
018
019 public class QDParser
020 {
021 private static int popMode(Stack st)
022 {
023 if(!st.empty())
024 return ((Integer)st.pop()).intValue();
025 else
026 return PRE;
027 }
028 private final static int
029 TEXT = 1,
030 ENTITY = 2,
031 OPEN_TAG = 3,
032 CLOSE_TAG = 4,
033 START_TAG = 5,
034 ATTRIBUTE_LVALUE = 6,
035 ATTRIBUTE_EQUAL = 9,
036 ATTRIBUTE_RVALUE = 10,
037 QUOTE = 7,
038 IN_TAG = 8,
039 SINGLE_TAG = 12,
040 COMMENT = 13,
041 DONE = 11,
042 DOCTYPE = 14,
043 PRE = 15,
044 CDATA = 16;
045 public static void parse(DocHandler doc,Reader r) throws Exception
046 {
047 Stack st = new Stack();
048 int depth = 0;
049 int mode = PRE;
050 int c = 0;
051 int quotec = '"';
052 depth = 0;
053 StringBuffer sb = new StringBuffer();
054 StringBuffer etag = new StringBuffer();
055 String tagName = null;
056 String lvalue = null;
057 String rvalue = null;
058 Hashtable attrs = null;
059 st = new Stack();
060 doc.startDocument();
061 int line=1, col=0;
062 boolean eol = false;
063 String nextchar = new String("");
064 while((c = r.read()) != -1)
065 {
066
067 // We need to map \r, \r\n, and \n to \n
068 // See XML spec section 2.11
069 if(c == '\n' && eol)
070 {
071 eol = false;
072 continue;
073 } else if(eol)
074 {
075 eol = false;
076 } else if(c == '\n')
077 {
078 line++;
079 col=0;
080 } else if(c == '\r')
081 {
082 eol = true;
083 c = '\n';
084 line++;
085 col=0;
086 } else
087 {
088 col++;
089 }
090
091 if(mode == DONE)
092 {
093 doc.endDocument();
094 return;
095
096 // We are between tags collecting text.
097 } else if(mode == TEXT)
098 {
099 if(c == '<')
100 {
101 st.push(new Integer(mode));
102 mode = START_TAG;
103 if(sb.length() > 0)
104 {
105 doc.text(sb.toString());
106 sb.setLength(0);
107 }
108 } else if(c == '&')
109 {
110 st.push(new Integer(mode));
111 mode = ENTITY;
112 etag.setLength(0);
113 } else
114 sb.append((char)c);
115
116 // we are processing a closing tag: e.g. </foo>
117 } else if(mode == CLOSE_TAG)
118 {
119 if(c == '>')
120 {
121 mode = popMode(st);
122 tagName = sb.toString();
123 sb.setLength(0);
124 depth--;
125 if(depth==0)
126 mode = DONE;
127 doc.endElement(tagName);
128 } else
129 {
130 sb.append((char)c);
131 }
132
133 // we are processing CDATA
134 } else if(mode == CDATA)
135 {
136 if(c == '>'
137 && sb.toString().endsWith("]]"))
138 {
139 sb.setLength(sb.length()-2);
140 doc.text(sb.toString());
141 sb.setLength(0);
142 mode = popMode(st);
143 } else
144 sb.append((char)c);
145
146 // we are processing a comment. We are inside
147 // the <!-- .... --> looking for the -->.
148 } else if(mode == COMMENT)
149 {
150 if(c == '>'
151 && sb.toString().endsWith("--"))
152 {
153 sb.setLength(0);
154 mode = popMode(st);
155 } else
156 sb.append((char)c);
157
158 // We are outside the root tag element
159 } else if(mode == PRE)
160 {
161 if(c == '<')
162 {
163 mode = TEXT;
164 st.push(new Integer(mode));
165 mode = START_TAG;
166 }
167
168 // We are inside one of these <? ... ?>
169 // or one of these <!DOCTYPE ... >
170 } else if(mode == DOCTYPE)
171 {
172 if(c == '>')
173 {
174 mode = popMode(st);
175 if(mode == TEXT) mode = PRE;
176 }
177
178 // we have just seen a < and
179 // are wondering what we are looking at
180 // <foo>, </foo>, <!-- ... --->, etc.
181 } else if(mode == START_TAG)
182 {
183 mode = popMode(st);
184 if(c == '/')
185 {
186 st.push(new Integer(mode));
187 mode = CLOSE_TAG;
188 } else if (c == '?')
189 {
190 mode = DOCTYPE;
191 } else
192 {
193 st.push(new Integer(mode));
194 mode = OPEN_TAG;
195 tagName = null;
196 attrs = new Hashtable();
197 sb.append((char)c);
198 }
199
200 // we are processing an entity, e.g. <, », etc.
201 } else if(mode == ENTITY)
202 {
203 if(c == ';')
204 {
205 mode = popMode(st);
206 String cent = etag.toString();
207 etag.setLength(0);
208 if(cent.equals("lt"))
209 sb.append('<');
210 else if(cent.equals("gt"))
211 sb.append('>');
212 else if(cent.equals("amp"))
213 sb.append('&');
214 else if(cent.equals("quot"))
215 sb.append('"');
216 else if(cent.equals("apos"))
217 sb.append('\'');
218 // Could parse hex entities if we wanted to
219 //else if(cent.startsWith("#x"))
220 //sb.append((char)Integer.parseInt(cent.substring(2),16));
221 else if(cent.startsWith("#"))
222 sb.append((char)Integer.parseInt(cent.substring(1)));
223 // Insert custom entity definitions here
224 else
225 exc("Unknown entity: &"+cent+";",line,col);
226 } else
227 {
228 etag.append((char)c);
229 }
230
231 // we have just seen something like this:
232 // <foo a="b"/
233 // and are looking for the final >.
234 } else if(mode == SINGLE_TAG)
235 {
236 if(tagName == null)
237 tagName = sb.toString();
238 if(c != '>')
239 exc("Expected > for tag: <"+tagName+"/>",line,col);
240 doc.startElement(tagName,attrs);
241 doc.endElement(tagName);
242 if(depth==0)
243 {
244 doc.endDocument();
245 return;
246 }
247 sb.setLength(0);
248 attrs = new Hashtable();
249 tagName = null;
250 mode = popMode(st);
251
252 // we are processing something
253 // like this <foo ... >. It could
254 // still be a <!-- ... --> or something.
255 } else if(mode == OPEN_TAG)
256 {
257 if(c == '>')
258 {
259 if(tagName == null)
260 tagName = sb.toString();
261 sb.setLength(0);
262 depth++;
263 doc.startElement(tagName,attrs);
264 tagName = null;
265 attrs = new Hashtable();
266 mode = popMode(st);
267 } else if(c == '/')
268 {
269 mode = SINGLE_TAG;
270 } else if(c == '-' && sb.toString().equals("!-"))
271 {
272 mode = COMMENT;
273 } else if(c == '[' && sb.toString().equals("![CDATA"))
274 {
275 mode = CDATA;
276 sb.setLength(0);
277 } else if(c == 'E' && sb.toString().equals("!DOCTYP"))
278 {
279 sb.setLength(0);
280 mode = DOCTYPE;
281 } else if(Character.isWhitespace((char)c))
282 {
283 tagName = sb.toString();
284 sb.setLength(0);
285 mode = IN_TAG;
286 } else
287 {
288 sb.append((char)c);
289 }
290
291 // We are processing the quoted right-hand side
292 // of an element's attribute.
293 } else if(mode == QUOTE)
294 {
295 if(c == quotec)
296 {
297 rvalue = sb.toString();
298 sb.setLength(0);
299 attrs.put(lvalue,rvalue);
300 mode = IN_TAG;
301 // See section the XML spec, section 3.3.3
302 // on normalization processing.
303 } else if(" \r\n\u0009".indexOf(c)>=0)
304 {
305 sb.append(' ');
306 } else if(c == '&')
307 {
308 st.push(new Integer(mode));
309 mode = ENTITY;
310 etag.setLength(0);
311 } else
312 {
313 sb.append((char)c);
314 }
315
316 } else if(mode == ATTRIBUTE_RVALUE)
317 {
318 if(c == '"' || c == '\'')
319 {
320 quotec = c;
321 mode = QUOTE;
322 } else if(Character.isWhitespace((char)c))
323 {
324 ;
325 } else
326 {
327 exc("Error in attribute processing",line,col);
328 }
329
330 } else if(mode == ATTRIBUTE_LVALUE)
331 {
332 if(Character.isWhitespace((char)c))
333 {
334 lvalue = sb.toString();
335 sb.setLength(0);
336 mode = ATTRIBUTE_EQUAL;
337 } else if(c == '=')
338 {
339 lvalue = sb.toString();
340 sb.setLength(0);
341 mode = ATTRIBUTE_RVALUE;
342 } else
343 {
344 sb.append((char)c);
345 }
346
347 } else if(mode == ATTRIBUTE_EQUAL)
348 {
349 if(c == '=')
350 {
351 mode = ATTRIBUTE_RVALUE;
352 } else if(Character.isWhitespace((char)c))
353 {
354 ;
355 } else
356 {
357 exc("Error in attribute processing.",line,col);
358 }
359
360 } else if(mode == IN_TAG)
361 {
362 if(c == '>')
363 {
364 mode = popMode(st);
365 doc.startElement(tagName,attrs);
366 depth++;
367 tagName = null;
368 attrs = new Hashtable();
369 } else if(c == '/')
370 {
371 mode = SINGLE_TAG;
372 } else if(Character.isWhitespace((char)c))
373 {
374 ;
375 } else
376 {
377 mode = ATTRIBUTE_LVALUE;
378 sb.append((char)c);
379 }
380 }
381 }
382 if(mode == DONE)
383 doc.endDocument();
384 else
385 exc("missing end tag",line,col);
386 }
387 private static void exc(String s,int line,int col)
388 throws Exception
389 {
390 throw new Exception(s+" near line "+line+", column "+col);
391 }
392 }