1 /**
2 * Redistribution and use of this software and associated documentation ("Software"), with or
3 * without modification, are permitted provided that the following conditions are met:
4 *
5 * 1. Redistributions of source code must retain copyright statements and notices. Redistributions
6 * must also contain a copy of this document.
7 *
8 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
9 * conditions and the following disclaimer in the documentation and/or other materials provided with
10 * the distribution.
11 *
12 * 3. The name "Exolab" must not be used to endorse or promote products derived from this Software
13 * without prior written permission of Intalio, Inc. For written permission, please contact
14 * info@exolab.org.
15 *
16 * 4. Products derived from this Software may not be called "Exolab" nor may "Exolab" appear in
17 * their names without prior written permission of Intalio, Inc. Exolab is a registered trademark of
18 * Intalio, Inc.
19 *
20 * 5. Due credit should be given to the Exolab Project (http://www.exolab.org/).
21 *
22 * THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESSED OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
24 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTALIO, INC. OR ITS
25 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
28 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
29 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 *
31 * Copyright 2002-2003 (C) Intalio, Inc. All Rights Reserved.
32 *
33 * $Id$
34 */
35 package org.exolab.castor.net.util;
36
37
38 import java.io.*;
39 import java.net.URL;
40 import java.net.MalformedURLException;
41 import java.util.Stack;
42 import java.util.StringTokenizer;
43
44 import org.apache.commons.lang3.StringUtils;
45
46 /**
47 * A utility class for URI handling
48 *
49 * @author <a href="mailto:kvisco-at-intalio.com">Keith Visco</a>
50 **/
51 public class URIUtils {
52
53 /**
54 * the File protocol
55 **/
56 private static final String FILE_PROTOCOL_PREFIX = "file:///";
57
58 /**
59 * the path separator for an URI
60 */
61 private static final char HREF_PATH_SEP = '/';
62
63 /**
64 * the path separate for a URL as a String
65 */
66 private static final String URL_PATH_SEP_STR = "/";
67
68 /**
69 * The current directory designator
70 */
71 private static final String CURRENT_DIR_OP = ".";
72
73 /**
74 * The parent directory designator
75 */
76 private static final String PARENT_DIR_OP = "..";
77
78 /**
79 * Returns an InputStream for the file represented by the href argument
80 *
81 * @param href the href of the file to get the input stream for.
82 * @param documentBase the document base of the href argument, if it is a relative href set
83 * documentBase to null if there is none.
84 * @return an InputStream to the desired resource
85 * @throws java.io.FileNotFoundException when the file could not be found
86 * @throws java.io.IOException
87 */
88 public static InputStream getInputStream(String href, String documentBase)
89 throws java.io.FileNotFoundException, java.io.IOException {
90
91 // -- check for absolute url
92 URL url = null;
93 try {
94 url = new URL(href);
95 return url.openStream();
96 } catch (MalformedURLException muex) {
97 }
98
99 // -- join document base + href
100 String xHref = null;
101 if ((documentBase != null) && (documentBase.length() > 0)) {
102 int idx = documentBase.lastIndexOf(HREF_PATH_SEP);
103 if (idx == (documentBase.length() - 1))
104 xHref = documentBase + href;
105 else
106 xHref = documentBase + HREF_PATH_SEP + href;
107 } else
108 xHref = href;
109
110 // -- check for relative url
111 try {
112 url = new URL(xHref);
113 return url.openStream();
114 } catch (MalformedURLException muex) {
115 }
116
117 // Try local files
118 File iFile = new File(href);
119 if (iFile.isAbsolute())
120 return new FileInputStream(iFile);
121
122 iFile = new File(xHref);
123 return new FileInputStream(iFile);
124
125 } // -- getInputStream
126
127 /**
128 * Returns a Reader for the file represented by the href argument
129 *
130 * @param href the href of the file to get the input stream for.
131 * @param documentBase the document base of the href argument, if it is a relative href set
132 * documentBase to null if there is none.
133 * @return an InputStream to the desired resource
134 * @exception java.io.FileNotFoundException when the file could not be found
135 **/
136 public static Reader getReader(String href, String documentBase)
137 throws java.io.FileNotFoundException, java.io.IOException {
138 InputStream is = getInputStream(href, documentBase);
139 return new InputStreamReader(is);
140 } // -- getReader
141
142 /**
143 * Returns the document base of the href argument
144 *
145 * @return the document base of the given href
146 **/
147 public static String getDocumentBase(String href) {
148
149 String docBase = "";
150
151 if (href == null)
152 return docBase;
153
154 int idx = -1;
155 // -- check for URL
156 try {
157 // -- try to create a new URL and see if MalformedURLExcetion is
158 // -- ever thrown
159 new URL(href);
160 idx = href.lastIndexOf(HREF_PATH_SEP);
161 } catch (MalformedURLException muex) {
162 // -- The following contains a fix from Shane Hathaway
163 // -- to handle the case when both "\" and "/" appear in filename
164 int idx2 = href.lastIndexOf(HREF_PATH_SEP);
165 idx = href.lastIndexOf(File.separator);
166 if (idx2 > idx)
167 idx = idx2;
168 }
169
170 if (idx >= 0)
171 docBase = href.substring(0, idx);
172
173 return docBase;
174 } // -- getDocumentBase
175
176 /**
177 * Returns the relative URI of the href argument
178 *
179 * @return the relative URI the given href
180 **/
181 public static String getRelativeURI(String href) {
182
183 if (href == null)
184 return href;
185
186 int idx = -1;
187 // -- check for URL
188 try {
189 // -- try to create a new URL and see if MalformedURLExcetion is
190 // -- ever thrown
191 new URL(href);
192 idx = href.lastIndexOf(HREF_PATH_SEP);
193 } catch (MalformedURLException muex) {
194 // -- The following contains a fix from Shane Hathaway
195 // -- to handle the case when both "\" and "/" appear in filename
196 int idx2 = href.lastIndexOf(HREF_PATH_SEP);
197 idx = href.lastIndexOf(File.separator);
198 if (idx2 > idx)
199 idx = idx2;
200 }
201
202 if (idx >= 0)
203 return href.substring(idx + 1);
204
205 return href;
206 } // -- getRelativeURI
207
208 /**
209 * This method removes "." or ".." from absolute URL. I needed this method because the JDK doesn't
210 * do this automatically when creating URLs.
211 *
212 * @param absoluteURL the absolute URI to normalize
213 */
214 public static String normalize(String absoluteURL) throws MalformedURLException {
215 if (absoluteURL == null)
216 return absoluteURL;
217 if (absoluteURL.indexOf('.') < 0)
218 return absoluteURL;
219
220 // -- Note: using StringTokenizer and Stacks
221 // -- is not very efficient, this may need
222 // -- some optimizing
223 Stack tokens = new Stack();
224 StringTokenizer st = new StringTokenizer(absoluteURL, URL_PATH_SEP_STR, true);
225 String last = null;
226 while (st.hasMoreTokens()) {
227 String token = st.nextToken();
228 if (URL_PATH_SEP_STR.equals(token)) {
229 if (URL_PATH_SEP_STR.equals(last)) {
230 tokens.push("");
231 }
232 } else if (PARENT_DIR_OP.equals(token)) {
233 if (tokens.empty()) {
234 // -- this should be an error
235 throw new MalformedURLException("invalid absolute URL: " + absoluteURL);
236 }
237 tokens.pop();
238 } else {
239 if (!CURRENT_DIR_OP.equals(token)) {
240 tokens.push(token);
241 }
242 }
243 last = token;
244 }
245
246 // -- rebuild URL
247 return StringUtils.join(tokens, HREF_PATH_SEP);
248 } // -- normalize
249
250
251 /**
252 *
253 **/
254 public static String resolveAsString(String href, String documentBase) {
255
256 try {
257 // -- try to create a new URL and see if MalformedURLExcetion is
258 // -- ever thrown
259 new URL(href);
260 return href;
261 } catch (MalformedURLException muex) {
262 }
263
264
265 // -- join document base + href
266 String absolute = null;
267 if ((documentBase != null) && (documentBase.length() > 0)) {
268 int idx = documentBase.lastIndexOf(HREF_PATH_SEP);
269 if (idx == (documentBase.length() - 1))
270 absolute = documentBase + href;
271 else
272 absolute = documentBase + HREF_PATH_SEP + href;
273
274
275 } else
276 absolute = href;
277
278
279 try {
280 // -- try to create a new URL and see if MalformedURLExcetion is
281 // -- ever thrown
282
283 if (absolute.indexOf("./") >= 0) {
284 // -- normalize . or .. from URL
285 absolute = normalize(absolute);
286 }
287 new URL(absolute);
288 return absolute;
289 } catch (MalformedURLException muex) {
290 // -- check for unrecognized protocol
291 int idx = absolute.indexOf(':');
292 if (idx >= 0) {
293 String scheme = absolute.substring(0, idx);
294 // -- a bit of a hack, but good enough for now
295 String error = "unknown protocol: " + scheme;
296 if (error.equals(muex.getMessage())) {
297 return absolute;
298 }
299 }
300
301 }
302
303
304 // Try local files
305 String fileURL = absolute;
306 File iFile = new File(href);
307 boolean exists = iFile.exists();
308 fileURL = createFileURL(iFile.getAbsolutePath());
309 if (!iFile.isAbsolute()) {
310 iFile = new File(absolute);
311 if (iFile.exists() || (!exists)) {
312 fileURL = createFileURL(iFile.getAbsolutePath());
313 }
314 }
315
316 // -- one last sanity check
317 try {
318 // -- try to create a new URL and see if MalformedURLExcetion is
319 // -- ever thrown
320 new URL(fileURL);
321 return fileURL;
322 } catch (MalformedURLException muex) {
323 }
324
325 // -- At this point we we're unsucessful at trying to resolve
326 // -- the href + documentbase, this could be due to a custom
327 // -- protocol or typo in the URI, just return documentBase +
328 // -- href
329 return absolute;
330 } // -- resolveHref
331
332 /**
333 * Creates a File URL for the given file name
334 *
335 * @param filename the name of the file
336 * @return the String representation of the File URL
337 **/
338 private static String createFileURL(String filename) {
339
340 if (filename == null)
341 return FILE_PROTOCOL_PREFIX;
342 int size = filename.length() + FILE_PROTOCOL_PREFIX.length();
343 StringBuilder sb = new StringBuilder(size);
344 sb.append(FILE_PROTOCOL_PREFIX);
345 char[] chars = filename.toCharArray();
346 for (char ch : chars) {
347 if ('\\' == ch) {
348 sb.append(HREF_PATH_SEP);
349 } else {
350 sb.append(ch);
351 }
352 }
353 return sb.toString();
354 } // -- createFileURL
355
356
357 } // -- URIUtils