|
1
21
22
23
24 package nu.xom.xinclude;
25
26 import java.util.ArrayList  ;
27 import java.util.List ;
28
29 import nu.xom.Attribute;
30 import nu.xom.Document;
31 import nu.xom.Element;
32 import nu.xom.IllegalNameException;
33 import nu.xom.Node;
34 import nu.xom.Nodes;
35 import nu.xom.ParentNode;
36 import nu.xom.XMLException;
37
38
50 class XPointer {
51
52
53 private XPointer() {}
55
56
57 public static Nodes query(Document doc, String xptr)
58 throws XPointerSyntaxException, XPointerResourceException {
59
60 Nodes result = new Nodes();
61 boolean found = false;
62
63 try { new Element(xptr, "http://www.example.com");
66 Element identified = findByID(doc.getRootElement(), xptr);
67 if (identified != null) {
68 result.append(identified);
69 return result;
70 }
71 }
72 catch (IllegalNameException ex) {
73 List elementSchemeData = findElementSchemeData(xptr);
75 if (elementSchemeData.size() == 0) {
76 throw new XPointerSyntaxException(
79 "No supported XPointer schemes found"
80 );
81 }
82
83 for (int i = 0; i < elementSchemeData.size(); i++) {
84 String currentData = (String ) (elementSchemeData.get(i));
85 int[] keys = new int[0];
86 ParentNode current = doc;
87 if (currentData.indexOf('/') == -1) {
88 try {
90 new Element(currentData);
91 }
92 catch (IllegalNameException inex) {
93 continue;
102 }
103 Element identified = findByID(
104 doc.getRootElement(), currentData);
105 if (identified != null) {
106 if (!found) result.append(identified);
107 found = true;
108 }
109 }
110 else if (!currentData.startsWith("/")) {
111 String id = currentData.substring(
112 0, currentData.indexOf('/'));
113 try {
116 new Element(id);
117 }
118 catch (XMLException inex) {
119 continue;
126 }
127 current = findByID(doc.getRootElement(), id);
128 keys = split(currentData.substring(
129 currentData.indexOf('/')));
130
131 if (current == null) continue;
132 }
133 else {
134 keys = split(currentData);
135 }
136
137 for (int j = 0; j < keys.length; j++) {
138 current = findNthChildElement(current, keys[j]);
139 if (current == null) break;
140 }
141
142 if (current != doc && current != null) {
143 if (!found) result.append(current);
144 found = true;
145 }
146
147 }
148
149 }
150
151 if (found) return result;
152 else {
153 throw new XPointerResourceException(
156 "XPointer " + xptr
157 + " did not locate any nodes in the document "
158 + doc.getBaseURI()
159 );
160 }
161
162 }
163
164
165 private static Element findNthChildElement(
166 ParentNode parent, int position) {
167 int elementCount = 1;
169 for (int i = 0; i < parent.getChildCount(); i++) {
170 Node child = parent.getChild(i);
171 if (child instanceof Element) {
172 if (elementCount == position) return (Element) child;
173 elementCount++;
174 }
175 }
176 return null;
177 }
178
179
180 private static int[] split(String tumbler)
181 throws XPointerSyntaxException {
182
183 int numberOfParts = 0;
184 for (int i = 0; i < tumbler.length(); i++) {
185 if (tumbler.charAt(i) == '/') numberOfParts++;
186 }
187
188 int[] result = new int[numberOfParts];
189 int index = 0;
190 StringBuffer part = new StringBuffer (3);
191 try {
192 for (int i = 1; i < tumbler.length(); i++) {
193 if (tumbler.charAt(i) == '/') {
194 result[index] = Integer.parseInt(part.toString());
195 index++;
196 part = new StringBuffer (3);
197 }
198 else {
199 part.append(tumbler.charAt(i));
200 }
201 }
202 result[result.length-1] = Integer.parseInt(part.toString());
203 }
204 catch (NumberFormatException ex) {
205 XPointerSyntaxException ex2
206 = new XPointerSyntaxException(tumbler
207 + " is not syntactically correct", ex);
208 throw ex2;
209 }
210
211 return result;
212 }
213
214 private static List findElementSchemeData(String xpointer)
215 throws XPointerSyntaxException {
216
217 List result = new ArrayList (1);
218
219 StringBuffer xptr = new StringBuffer (xpointer.trim());
220 StringBuffer scheme = new StringBuffer ();
221 int i = 0;
222 while (i < xptr.length()) {
223 char c = xptr.charAt(i);
224 if (c == '(') break;
225 else scheme.append(c);
226 i++;
227 }
228
229 try {
231 new Element(scheme.toString(), "http://www.example.com/");
233 }
234 catch (IllegalNameException ex) {
235 throw new XPointerSyntaxException(ex.getMessage());
236 }
237
238 int open = 1; i++;
240 StringBuffer schemeData = new StringBuffer ();
241 try {
242 while (open > 0) {
243 char c = xptr.charAt(i);
244 if (c == '^') {
245 c = xptr.charAt(i+1);
246 schemeData.append(c);
247 if (c != '^' && c != '(' && c != ')') {
248 throw new XPointerSyntaxException(
249 "Illegal XPointer escape sequence"
250 );
251 }
252 i++;
253 }
254 else if (c == '(') {
255 schemeData.append(c);
256 open++;
257 }
258 else if (c == ')') {
259 open--;
260 if (open > 0) schemeData.append(c);
261 }
262 else {
263 schemeData.append(c);
264 }
265 i++;
266 }
267 }
268 catch (StringIndexOutOfBoundsException ex) {
269 throw new XPointerSyntaxException("Unbalanced parentheses");
270 }
271
272 if (scheme.toString().equals("element")) {
273 result.add(schemeData.toString());
274 }
275
276 if (i + 1 < xptr.length()) {
277 result.addAll(findElementSchemeData(xptr.substring(i)));
278 }
279
280 return result;
281 }
282
283
284 public static Element findByID(Element element, String id) {
285
286 Node current = element;
287 boolean end = false;
288 int index = -1;
289 while (true) {
290
291 if (current instanceof Element) {
292 Element currentElement = (Element) current;
293 for (int i = 0; i < currentElement.getAttributeCount(); i++) {
294 Attribute att = currentElement.getAttribute(i);
295 if (att.getType() == Attribute.Type.ID) {
296 if (att.getValue().trim().equals(id)) {
297 return currentElement;
298 }
299 }
300 }
301 }
302
303 if (!end && current.getChildCount() > 0) {
304 current = current.getChild(0);
305 index = 0;
306 }
307 else {
308 if (end) {
309 if (current == element) break;
310 }
311 end = false;
312 ParentNode parent = current.getParent();
313 if (parent.getChildCount() - 1 == index) {
314 current = parent;
315 if (current != element) {
316 parent = current.getParent();
317 index = parent.indexOf(current);
318 }
319 end = true;
320 }
321 else {
322 index++;
323 current = parent.getChild(index);
324 }
325 }
326 }
327
328 return null;
329
330 }
331
332
333 }
334 |
Popular Tags |
Java API By Example, From Geeks To Geeks.