001 /*
002 * Copyright 1995-2006 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package java.net;
027
028 import java.io.IOException;
029 import java.io.InputStream;
030 import java.io.File;
031 import java.io.OutputStream;
032 import java.util.Hashtable;
033 import sun.net.util.IPAddressUtil;
034 import sun.net.www.ParseUtil;
035
036 /**
037 * The abstract class <code>URLStreamHandler</code> is the common
038 * superclass for all stream protocol handlers. A stream protocol
039 * handler knows how to make a connection for a particular protocol
040 * type, such as <code>http</code>, <code>ftp</code>, or
041 * <code>gopher</code>.
042 * <p>
043 * In most cases, an instance of a <code>URLStreamHandler</code>
044 * subclass is not created directly by an application. Rather, the
045 * first time a protocol name is encountered when constructing a
046 * <code>URL</code>, the appropriate stream protocol handler is
047 * automatically loaded.
048 *
049 * @author James Gosling
050 * @version 1.79, 05/05/07
051 * @see java.net.URL#URL(java.lang.String, java.lang.String, int, java.lang.String)
052 * @since JDK1.0
053 */
054 public abstract class URLStreamHandler {
055 /**
056 * Opens a connection to the object referenced by the
057 * <code>URL</code> argument.
058 * This method should be overridden by a subclass.
059 *
060 * <p>If for the handler's protocol (such as HTTP or JAR), there
061 * exists a public, specialized URLConnection subclass belonging
062 * to one of the following packages or one of their subpackages:
063 * java.lang, java.io, java.util, java.net, the connection
064 * returned will be of that subclass. For example, for HTTP an
065 * HttpURLConnection will be returned, and for JAR a
066 * JarURLConnection will be returned.
067 *
068 * @param u the URL that this connects to.
069 * @return a <code>URLConnection</code> object for the <code>URL</code>.
070 * @exception IOException if an I/O error occurs while opening the
071 * connection.
072 */
073 abstract protected URLConnection openConnection(URL u)
074 throws IOException;
075
076 /**
077 * Same as openConnection(URL), except that the connection will be
078 * made through the specified proxy; Protocol handlers that do not
079 * support proxying will ignore the proxy parameter and make a
080 * normal connection.
081 *
082 * Calling this method preempts the system's default ProxySelector
083 * settings.
084 *
085 * @param u the URL that this connects to.
086 * @param p the proxy through which the connection will be made.
087 * If direct connection is desired, Proxy.NO_PROXY
088 * should be specified.
089 * @return a <code>URLConnection</code> object for the <code>URL</code>.
090 * @exception IOException if an I/O error occurs while opening the
091 * connection.
092 * @exception IllegalArgumentException if either u or p is null,
093 * or p has the wrong type.
094 * @exception UnsupportedOperationException if the subclass that
095 * implements the protocol doesn't support this method.
096 * @since 1.5
097 */
098 protected URLConnection openConnection(URL u, Proxy p)
099 throws IOException {
100 throw new UnsupportedOperationException(
101 "Method not implemented.");
102 }
103
104 /**
105 * Parses the string representation of a <code>URL</code> into a
106 * <code>URL</code> object.
107 * <p>
108 * If there is any inherited context, then it has already been
109 * copied into the <code>URL</code> argument.
110 * <p>
111 * The <code>parseURL</code> method of <code>URLStreamHandler</code>
112 * parses the string representation as if it were an
113 * <code>http</code> specification. Most URL protocol families have a
114 * similar parsing. A stream protocol handler for a protocol that has
115 * a different syntax must override this routine.
116 *
117 * @param u the <code>URL</code> to receive the result of parsing
118 * the spec.
119 * @param spec the <code>String</code> representing the URL that
120 * must be parsed.
121 * @param start the character index at which to begin parsing. This is
122 * just past the '<code>:</code>' (if there is one) that
123 * specifies the determination of the protocol name.
124 * @param limit the character position to stop parsing at. This is the
125 * end of the string or the position of the
126 * "<code>#</code>" character, if present. All information
127 * after the sharp sign indicates an anchor.
128 */
129 protected void parseURL(URL u, String spec, int start, int limit) {
130 // These fields may receive context content if this was relative URL
131 String protocol = u.getProtocol();
132 String authority = u.getAuthority();
133 String userInfo = u.getUserInfo();
134 String host = u.getHost();
135 int port = u.getPort();
136 String path = u.getPath();
137 String query = u.getQuery();
138
139 // This field has already been parsed
140 String ref = u.getRef();
141
142 boolean isRelPath = false;
143 boolean queryOnly = false;
144
145 // FIX: should not assume query if opaque
146 // Strip off the query part
147 if (start < limit) {
148 int queryStart = spec.indexOf('?');
149 queryOnly = queryStart == start;
150 if ((queryStart != -1) && (queryStart < limit)) {
151 query = spec.substring(queryStart + 1, limit);
152 if (limit > queryStart)
153 limit = queryStart;
154 spec = spec.substring(0, queryStart);
155 }
156 }
157
158 int i = 0;
159 // Parse the authority part if any
160 boolean isUNCName = (start <= limit - 4)
161 && (spec.charAt(start) == '/')
162 && (spec.charAt(start + 1) == '/')
163 && (spec.charAt(start + 2) == '/')
164 && (spec.charAt(start + 3) == '/');
165 if (!isUNCName && (start <= limit - 2)
166 && (spec.charAt(start) == '/')
167 && (spec.charAt(start + 1) == '/')) {
168 start += 2;
169 i = spec.indexOf('/', start);
170 if (i < 0) {
171 i = spec.indexOf('?', start);
172 if (i < 0)
173 i = limit;
174 }
175
176 host = authority = spec.substring(start, i);
177
178 int ind = authority.indexOf('@');
179 if (ind != -1) {
180 userInfo = authority.substring(0, ind);
181 host = authority.substring(ind + 1);
182 } else {
183 userInfo = null;
184 }
185 if (host != null) {
186 // If the host is surrounded by [ and ] then its an IPv6
187 // literal address as specified in RFC2732
188 if (host.length() > 0 && (host.charAt(0) == '[')) {
189 if ((ind = host.indexOf(']')) > 2) {
190
191 String nhost = host;
192 host = nhost.substring(0, ind + 1);
193 if (!IPAddressUtil.isIPv6LiteralAddress(host
194 .substring(1, ind))) {
195 throw new IllegalArgumentException(
196 "Invalid host: " + host);
197 }
198
199 port = -1;
200 if (nhost.length() > ind + 1) {
201 if (nhost.charAt(ind + 1) == ':') {
202 ++ind;
203 // port can be null according to RFC2396
204 if (nhost.length() > (ind + 1)) {
205 port = Integer.parseInt(nhost
206 .substring(ind + 1));
207 }
208 } else {
209 throw new IllegalArgumentException(
210 "Invalid authority field: "
211 + authority);
212 }
213 }
214 } else {
215 throw new IllegalArgumentException(
216 "Invalid authority field: " + authority);
217 }
218 } else {
219 ind = host.indexOf(':');
220 port = -1;
221 if (ind >= 0) {
222 // port can be null according to RFC2396
223 if (host.length() > (ind + 1)) {
224 port = Integer.parseInt(host
225 .substring(ind + 1));
226 }
227 host = host.substring(0, ind);
228 }
229 }
230 } else {
231 host = "";
232 }
233 if (port < -1)
234 throw new IllegalArgumentException(
235 "Invalid port number :" + port);
236 start = i;
237 // If the authority is defined then the path is defined by the
238 // spec only; See RFC 2396 Section 5.2.4.
239 if (authority != null && authority.length() > 0)
240 path = "";
241 }
242
243 if (host == null) {
244 host = "";
245 }
246
247 // Parse the file path if any
248 if (start < limit) {
249 if (spec.charAt(start) == '/') {
250 path = spec.substring(start, limit);
251 } else if (path != null && path.length() > 0) {
252 isRelPath = true;
253 int ind = path.lastIndexOf('/');
254 String seperator = "";
255 if (ind == -1 && authority != null)
256 seperator = "/";
257 path = path.substring(0, ind + 1) + seperator
258 + spec.substring(start, limit);
259
260 } else {
261 String seperator = (authority != null) ? "/" : "";
262 path = seperator + spec.substring(start, limit);
263 }
264 } else if (queryOnly && path != null) {
265 int ind = path.lastIndexOf('/');
266 if (ind < 0)
267 ind = 0;
268 path = path.substring(0, ind) + "/";
269 }
270 if (path == null)
271 path = "";
272
273 if (isRelPath) {
274 // Remove embedded /./
275 while ((i = path.indexOf("/./")) >= 0) {
276 path = path.substring(0, i) + path.substring(i + 2);
277 }
278 // Remove embedded /../ if possible
279 i = 0;
280 while ((i = path.indexOf("/../", i)) >= 0) {
281 /*
282 * A "/../" will cancel the previous segment and itself,
283 * unless that segment is a "/../" itself
284 * i.e. "/a/b/../c" becomes "/a/c"
285 * but "/../../a" should stay unchanged
286 */
287 if (i > 0
288 && (limit = path.lastIndexOf('/', i - 1)) >= 0
289 && (path.indexOf("/../", limit) != 0)) {
290 path = path.substring(0, limit)
291 + path.substring(i + 3);
292 i = 0;
293 } else {
294 i = i + 3;
295 }
296 }
297 // Remove trailing .. if possible
298 while (path.endsWith("/..")) {
299 i = path.indexOf("/..");
300 if ((limit = path.lastIndexOf('/', i - 1)) >= 0) {
301 path = path.substring(0, limit + 1);
302 } else {
303 break;
304 }
305 }
306 // Remove starting .
307 if (path.startsWith("./") && path.length() > 2)
308 path = path.substring(2);
309
310 // Remove trailing .
311 if (path.endsWith("/."))
312 path = path.substring(0, path.length() - 1);
313 }
314
315 setURL(u, protocol, host, port, authority, userInfo, path,
316 query, ref);
317 }
318
319 /**
320 * Returns the default port for a URL parsed by this handler. This method
321 * is meant to be overidden by handlers with default port numbers.
322 * @return the default port for a <code>URL</code> parsed by this handler.
323 * @since 1.3
324 */
325 protected int getDefaultPort() {
326 return -1;
327 }
328
329 /**
330 * Provides the default equals calculation. May be overidden by handlers
331 * for other protocols that have different requirements for equals().
332 * This method requires that none of its arguments is null. This is
333 * guaranteed by the fact that it is only called by java.net.URL class.
334 * @param u1 a URL object
335 * @param u2 a URL object
336 * @return <tt>true</tt> if the two urls are
337 * considered equal, ie. they refer to the same
338 * fragment in the same file.
339 * @since 1.3
340 */
341 protected boolean equals(URL u1, URL u2) {
342 String ref1 = u1.getRef();
343 String ref2 = u2.getRef();
344 return (ref1 == ref2 || (ref1 != null && ref1.equals(ref2)))
345 && sameFile(u1, u2);
346 }
347
348 /**
349 * Provides the default hash calculation. May be overidden by handlers for
350 * other protocols that have different requirements for hashCode
351 * calculation.
352 * @param u a URL object
353 * @return an <tt>int</tt> suitable for hash table indexing
354 * @since 1.3
355 */
356 protected int hashCode(URL u) {
357 int h = 0;
358
359 // Generate the protocol part.
360 String protocol = u.getProtocol();
361 if (protocol != null)
362 h += protocol.hashCode();
363
364 // Generate the host part.
365 InetAddress addr = getHostAddress(u);
366 if (addr != null) {
367 h += addr.hashCode();
368 } else {
369 String host = u.getHost();
370 if (host != null)
371 h += host.toLowerCase().hashCode();
372 }
373
374 // Generate the file part.
375 String file = u.getFile();
376 if (file != null)
377 h += file.hashCode();
378
379 // Generate the port part.
380 if (u.getPort() == -1)
381 h += getDefaultPort();
382 else
383 h += u.getPort();
384
385 // Generate the ref part.
386 String ref = u.getRef();
387 if (ref != null)
388 h += ref.hashCode();
389
390 return h;
391 }
392
393 /**
394 * Compare two urls to see whether they refer to the same file,
395 * i.e., having the same protocol, host, port, and path.
396 * This method requires that none of its arguments is null. This is
397 * guaranteed by the fact that it is only called indirectly
398 * by java.net.URL class.
399 * @param u1 a URL object
400 * @param u2 a URL object
401 * @return true if u1 and u2 refer to the same file
402 * @since 1.3
403 */
404 protected boolean sameFile(URL u1, URL u2) {
405 // Compare the protocols.
406 if (!((u1.getProtocol() == u2.getProtocol()) || (u1
407 .getProtocol() != null && u1.getProtocol()
408 .equalsIgnoreCase(u2.getProtocol()))))
409 return false;
410
411 // Compare the files.
412 if (!(u1.getFile() == u2.getFile() || (u1.getFile() != null && u1
413 .getFile().equals(u2.getFile()))))
414 return false;
415
416 // Compare the ports.
417 int port1, port2;
418 port1 = (u1.getPort() != -1) ? u1.getPort() : u1.handler
419 .getDefaultPort();
420 port2 = (u2.getPort() != -1) ? u2.getPort() : u2.handler
421 .getDefaultPort();
422 if (port1 != port2)
423 return false;
424
425 // Compare the hosts.
426 if (!hostsEqual(u1, u2))
427 return false;
428
429 return true;
430 }
431
432 /**
433 * Get the IP address of our host. An empty host field or a DNS failure
434 * will result in a null return.
435 *
436 * @param u a URL object
437 * @return an <code>InetAddress</code> representing the host
438 * IP address.
439 * @since 1.3
440 */
441 protected synchronized InetAddress getHostAddress(URL u) {
442 if (u.hostAddress != null)
443 return u.hostAddress;
444
445 String host = u.getHost();
446 if (host == null || host.equals("")) {
447 return null;
448 } else {
449 try {
450 u.hostAddress = InetAddress.getByName(host);
451 } catch (UnknownHostException ex) {
452 return null;
453 } catch (SecurityException se) {
454 return null;
455 }
456 }
457 return u.hostAddress;
458 }
459
460 /**
461 * Compares the host components of two URLs.
462 * @param u1 the URL of the first host to compare
463 * @param u2 the URL of the second host to compare
464 * @return <tt>true</tt> if and only if they
465 * are equal, <tt>false</tt> otherwise.
466 * @since 1.3
467 */
468 protected boolean hostsEqual(URL u1, URL u2) {
469 InetAddress a1 = getHostAddress(u1);
470 InetAddress a2 = getHostAddress(u2);
471 // if we have internet address for both, compare them
472 if (a1 != null && a2 != null) {
473 return a1.equals(a2);
474 // else, if both have host names, compare them
475 } else if (u1.getHost() != null && u2.getHost() != null)
476 return u1.getHost().equalsIgnoreCase(u2.getHost());
477 else
478 return u1.getHost() == null && u2.getHost() == null;
479 }
480
481 /**
482 * Converts a <code>URL</code> of a specific protocol to a
483 * <code>String</code>.
484 *
485 * @param u the URL.
486 * @return a string representation of the <code>URL</code> argument.
487 */
488 protected String toExternalForm(URL u) {
489
490 // pre-compute length of StringBuffer
491 int len = u.getProtocol().length() + 1;
492 if (u.getAuthority() != null && u.getAuthority().length() > 0)
493 len += 2 + u.getAuthority().length();
494 if (u.getPath() != null) {
495 len += u.getPath().length();
496 }
497 if (u.getQuery() != null) {
498 len += 1 + u.getQuery().length();
499 }
500 if (u.getRef() != null)
501 len += 1 + u.getRef().length();
502
503 StringBuffer result = new StringBuffer(len);
504 result.append(u.getProtocol());
505 result.append(":");
506 if (u.getAuthority() != null && u.getAuthority().length() > 0) {
507 result.append("//");
508 result.append(u.getAuthority());
509 }
510 if (u.getPath() != null) {
511 result.append(u.getPath());
512 }
513 if (u.getQuery() != null) {
514 result.append('?');
515 result.append(u.getQuery());
516 }
517 if (u.getRef() != null) {
518 result.append("#");
519 result.append(u.getRef());
520 }
521 return result.toString();
522 }
523
524 /**
525 * Sets the fields of the <code>URL</code> argument to the indicated values.
526 * Only classes derived from URLStreamHandler are supposed to be able
527 * to call the set method on a URL.
528 *
529 * @param u the URL to modify.
530 * @param protocol the protocol name.
531 * @param host the remote host value for the URL.
532 * @param port the port on the remote machine.
533 * @param authority the authority part for the URL.
534 * @param userInfo the userInfo part of the URL.
535 * @param path the path component of the URL.
536 * @param query the query part for the URL.
537 * @param ref the reference.
538 * @exception SecurityException if the protocol handler of the URL is
539 * different from this one
540 * @see java.net.URL#set(java.lang.String, java.lang.String, int, java.lang.String, java.lang.String)
541 * @since 1.3
542 */
543 protected void setURL(URL u, String protocol, String host,
544 int port, String authority, String userInfo, String path,
545 String query, String ref) {
546 if (this != u.handler) {
547 throw new SecurityException(
548 "handler for url different from " + "this handler");
549 }
550 // ensure that no one can reset the protocol on a given URL.
551 u.set(u.getProtocol(), host, port, authority, userInfo, path,
552 query, ref);
553 }
554
555 /**
556 * Sets the fields of the <code>URL</code> argument to the indicated values.
557 * Only classes derived from URLStreamHandler are supposed to be able
558 * to call the set method on a URL.
559 *
560 * @param u the URL to modify.
561 * @param protocol the protocol name. This value is ignored since 1.2.
562 * @param host the remote host value for the URL.
563 * @param port the port on the remote machine.
564 * @param file the file.
565 * @param ref the reference.
566 * @exception SecurityException if the protocol handler of the URL is
567 * different from this one
568 * @deprecated Use setURL(URL, String, String, int, String, String, String,
569 * String);
570 */
571 @Deprecated
572 protected void setURL(URL u, String protocol, String host,
573 int port, String file, String ref) {
574 /*
575 * Only old URL handlers call this, so assume that the host
576 * field might contain "user:passwd@host". Fix as necessary.
577 */
578 String authority = null;
579 String userInfo = null;
580 if (host != null && host.length() != 0) {
581 authority = (port == -1) ? host : host + ":" + port;
582 int at = host.lastIndexOf('@');
583 if (at != -1) {
584 userInfo = host.substring(0, at);
585 host = host.substring(at + 1);
586 }
587 }
588
589 /*
590 * Assume file might contain query part. Fix as necessary.
591 */
592 String path = null;
593 String query = null;
594 if (file != null) {
595 int q = file.lastIndexOf('?');
596 if (q != -1) {
597 query = file.substring(q + 1);
598 path = file.substring(0, q);
599 } else
600 path = file;
601 }
602 setURL(u, protocol, host, port, authority, userInfo, path,
603 query, ref);
604 }
605 }
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