1 /*
2 * Copyright (c) 1995, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.net;
27
28 import java.io.IOException;
29 import java.io.InputStream;
30 import java.io.File;
31 import java.io.OutputStream;
32 import java.util.Hashtable;
33 import java.util.Objects;
34 import sun.net.util.IPAddressUtil;
35 import sun.net.www.ParseUtil;
36
37 /**
38 * The abstract class {@code URLStreamHandler} is the common
39 * superclass for all stream protocol handlers. A stream protocol
40 * handler knows how to make a connection for a particular protocol
41 * type, such as {@code http} or {@code https}.
42 * <p>
43 * In most cases, an instance of a {@code URLStreamHandler}
44 * subclass is not created directly by an application. Rather, the
45 * first time a protocol name is encountered when constructing a
46 * {@code URL}, the appropriate stream protocol handler is
47 * automatically loaded.
48 *
49 * @author James Gosling
50 * @see java.net.URL#URL(java.lang.String, java.lang.String, int, java.lang.String)
51 * @since 1.0
52 */
53 public abstract class URLStreamHandler {
54 /**
55 * Constructor for subclasses to call.
56 */
57 public URLStreamHandler() {}
58
59 /**
60 * Opens a connection to the object referenced by the
61 * {@code URL} argument.
62 * This method should be overridden by a subclass.
63 *
64 * <p>If for the handler's protocol (such as HTTP or JAR), there
65 * exists a public, specialized URLConnection subclass belonging
66 * to one of the following packages or one of their subpackages:
67 * java.lang, java.io, java.util, java.net, the connection
68 * returned will be of that subclass. For example, for HTTP an
69 * HttpURLConnection will be returned, and for JAR a
70 * JarURLConnection will be returned.
71 *
72 * @param u the URL that this connects to.
73 * @return a {@code URLConnection} object for the {@code URL}.
74 * @throws IOException if an I/O error occurs while opening the
75 * connection.
76 */
77 protected abstract URLConnection openConnection(URL u) throws IOException;
78
79 /**
80 * Same as openConnection(URL), except that the connection will be
81 * made through the specified proxy; Protocol handlers that do not
82 * support proxying will ignore the proxy parameter and make a
83 * normal connection.
84 *
85 * <p> Calling this method preempts the system's default
86 * {@link java.net.ProxySelector ProxySelector} settings.
87 *
88 * @implSpec
89 * The default implementation of this method first checks that the given
90 * {@code URL} and {@code Proxy} are not null, then throws {@code
91 * UnsupportedOperationException}. Subclasses should override this method
92 * with an appropriate implementation.
93 *
94 * @param u the URL that this connects to.
95 * @param p the proxy through which the connection will be made.
96 * If direct connection is desired, Proxy.NO_PROXY
97 * should be specified.
98 * @return a {@code URLConnection} object for the {@code URL}.
99 * @throws IOException if an I/O error occurs while opening the
100 * connection.
101 * @throws IllegalArgumentException if either u or p is null,
102 * or p has the wrong type.
103 * @throws UnsupportedOperationException if the subclass that
104 * implements the protocol doesn't support this method.
105 * @since 1.5
106 */
107 protected URLConnection openConnection(URL u, Proxy p) throws IOException {
108 if (u == null || p == null)
109 throw new IllegalArgumentException("null " + (u == null ? "url" : "proxy"));
110 throw new UnsupportedOperationException("Method not implemented.");
111 }
112
113 /**
114 * Parses the string representation of a {@code URL} into a
115 * {@code URL} object.
116 * <p>
117 * If there is any inherited context, then it has already been
118 * copied into the {@code URL} argument.
119 * <p>
120 * The {@code parseURL} method of {@code URLStreamHandler}
121 * parses the string representation as if it were an
122 * {@code http} specification. Most URL protocol families have a
123 * similar parsing. A stream protocol handler for a protocol that has
124 * a different syntax must override this routine.
125 *
126 * @param u the {@code URL} to receive the result of parsing
127 * the spec.
128 * @param spec the {@code String} representing the URL that
129 * must be parsed.
130 * @param start the character index at which to begin parsing. This is
131 * just past the '{@code :}' (if there is one) that
132 * specifies the determination of the protocol name.
133 * @param limit the character position to stop parsing at. This is the
134 * end of the string or the position of the
135 * "{@code #}" character, if present. All information
136 * after the sharp sign indicates an anchor.
137 */
138 protected void parseURL(URL u, String spec, int start, int limit) {
139 // These fields may receive context content if this was relative URL
140 String protocol = u.getProtocol();
141 String authority = u.getAuthority();
142 String userInfo = u.getUserInfo();
143 String host = u.getHost();
144 int port = u.getPort();
145 String path = u.getPath();
146 String query = u.getQuery();
147
148 // This field has already been parsed
149 String ref = u.getRef();
150
151 boolean isRelPath = false;
152 boolean queryOnly = false;
153
154 // FIX: should not assume query if opaque
155 // Strip off the query part
156 if (start < limit) {
157 int queryStart = spec.indexOf('?');
158 queryOnly = queryStart == start;
159 if ((queryStart != -1) && (queryStart < limit)) {
160 query = spec.substring(queryStart+1, limit);
161 if (limit > queryStart)
162 limit = queryStart;
163 spec = spec.substring(0, queryStart);
164 }
165 }
166
167 int i = 0;
168 // Parse the authority part if any
169 boolean isUNCName = (start <= limit - 4) &&
170 (spec.charAt(start) == '/') &&
171 (spec.charAt(start + 1) == '/') &&
172 (spec.charAt(start + 2) == '/') &&
173 (spec.charAt(start + 3) == '/');
174 if (!isUNCName && (start <= limit - 2) && (spec.charAt(start) == '/') &&
175 (spec.charAt(start + 1) == '/')) {
176 start += 2;
177 i = spec.indexOf('/', start);
178 if (i < 0 || i > limit) {
179 i = spec.indexOf('?', start);
180 if (i < 0 || i > limit)
181 i = limit;
182 }
183
184 host = authority = spec.substring(start, i);
185
186 int ind = authority.indexOf('@');
187 if (ind != -1) {
188 if (ind != authority.lastIndexOf('@')) {
189 // more than one '@' in authority. This is not server based
190 userInfo = null;
191 host = null;
192 } else {
193 userInfo = authority.substring(0, ind);
194 host = authority.substring(ind+1);
195 }
196 } else {
197 userInfo = null;
198 }
199 if (host != null) {
200 // If the host is surrounded by [ and ] then its an IPv6
201 // literal address as specified in RFC2732
202 if (host.length()>0 && (host.charAt(0) == '[')) {
203 if ((ind = host.indexOf(']')) > 2) {
204
205 String nhost = host ;
206 host = nhost.substring(0,ind+1);
207 if (!IPAddressUtil.
208 isIPv6LiteralAddress(host.substring(1, ind))) {
209 throw new IllegalArgumentException(
210 "Invalid host: "+ host);
211 }
212
213 port = -1 ;
214 if (nhost.length() > ind+1) {
215 if (nhost.charAt(ind+1) == ':') {
216 ++ind ;
217 // port can be null according to RFC2396
218 if (nhost.length() > (ind + 1)) {
219 port = Integer.parseInt(nhost, ind + 1,
220 nhost.length(), 10);
221 }
222 } else {
223 throw new IllegalArgumentException(
224 "Invalid authority field: " + authority);
225 }
226 }
227 } else {
228 throw new IllegalArgumentException(
229 "Invalid authority field: " + authority);
230 }
231 } else {
232 ind = host.indexOf(':');
233 port = -1;
234 if (ind >= 0) {
235 // port can be null according to RFC2396
236 if (host.length() > (ind + 1)) {
237 port = Integer.parseInt(host, ind + 1,
238 host.length(), 10);
239 }
240 host = host.substring(0, ind);
241 }
242 }
243 } else {
244 host = "";
245 }
246 if (port < -1)
247 throw new IllegalArgumentException("Invalid port number :" +
248 port);
249 start = i;
250 // If the authority is defined then the path is defined by the
251 // spec only; See RFC 2396 Section 5.2.4.
252 if (authority != null && !authority.isEmpty())
253 path = "";
254 }
255
256 if (host == null) {
257 host = "";
258 }
259
260 // Parse the file path if any
261 if (start < limit) {
262 if (spec.charAt(start) == '/') {
263 path = spec.substring(start, limit);
264 } else if (path != null && !path.isEmpty()) {
265 isRelPath = true;
266 int ind = path.lastIndexOf('/');
267 String separator = "";
268 if (ind == -1 && authority != null)
269 separator = "/";
270 path = path.substring(0, ind + 1) + separator +
271 spec.substring(start, limit);
272
273 } else {
274 path = spec.substring(start, limit);
275 path = (authority != null) ? "/" + path : path;
276 }
277 } else if (queryOnly && path != null) {
278 int ind = path.lastIndexOf('/');
279 if (ind < 0)
280 ind = 0;
281 path = path.substring(0, ind) + "/";
282 }
283 if (path == null)
284 path = "";
285
286 if (isRelPath) {
287 // Remove embedded /./
288 while ((i = path.indexOf("/./")) >= 0) {
289 path = path.substring(0, i) + path.substring(i + 2);
290 }
291 // Remove embedded /../ if possible
292 i = 0;
293 while ((i = path.indexOf("/../", i)) >= 0) {
294 /*
295 * A "/../" will cancel the previous segment and itself,
296 * unless that segment is a "/../" itself
297 * i.e. "/a/b/../c" becomes "/a/c"
298 * but "/../../a" should stay unchanged
299 */
300 if (i > 0 && (limit = path.lastIndexOf('/', i - 1)) >= 0 &&
301 (path.indexOf("/../", limit) != 0)) {
302 path = path.substring(0, limit) + path.substring(i + 3);
303 i = 0;
304 } else {
305 i = i + 3;
306 }
307 }
308 // Remove trailing .. if possible
309 while (path.endsWith("/..")) {
310 i = path.indexOf("/..");
311 if ((limit = path.lastIndexOf('/', i - 1)) >= 0) {
312 path = path.substring(0, limit+1);
313 } else {
314 break;
315 }
316 }
317 // Remove starting .
318 if (path.startsWith("./") && path.length() > 2)
319 path = path.substring(2);
320
321 // Remove trailing .
322 if (path.endsWith("/."))
323 path = path.substring(0, path.length() -1);
324 }
325
326 setURL(u, protocol, host, port, authority, userInfo, path, query, ref);
327 }
328
329 /**
330 * Returns the default port for a URL parsed by this handler. This method
331 * is meant to be overridden by handlers with default port numbers.
332 * @return the default port for a {@code URL} parsed by this handler.
333 * @since 1.3
334 */
335 protected int getDefaultPort() {
336 return -1;
337 }
338
339 /**
340 * Provides the default equals calculation. May be overridden by handlers
341 * for other protocols that have different requirements for equals().
342 * This method requires that none of its arguments is null. This is
343 * guaranteed by the fact that it is only called by java.net.URL class.
344 * @param u1 a URL object
345 * @param u2 a URL object
346 * @return {@code true} if the two urls are
347 * considered equal, i.e. they refer to the same
348 * fragment in the same file.
349 * @since 1.3
350 */
351 protected boolean equals(URL u1, URL u2) {
352 return Objects.equals(u1.getRef(), u2.getRef()) && sameFile(u1, u2);
353 }
354
355 /**
356 * Provides the default hash calculation. May be overridden by handlers for
357 * other protocols that have different requirements for hashCode
358 * calculation.
359 * @param u a URL object
360 * @return an {@code int} suitable for hash table indexing
361 * @since 1.3
362 */
363 protected int hashCode(URL u) {
364 int h = 0;
365
366 // Generate the protocol part.
367 String protocol = u.getProtocol();
368 if (protocol != null)
369 h += protocol.hashCode();
370
371 // Generate the host part.
372 InetAddress addr = getHostAddress(u);
373 if (addr != null) {
374 h += addr.hashCode();
375 } else {
376 String host = u.getHost();
377 if (host != null)
378 h += host.toLowerCase().hashCode();
379 }
380
381 // Generate the file part.
382 String file = u.getFile();
383 if (file != null)
384 h += file.hashCode();
385
386 // Generate the port part.
387 if (u.getPort() == -1)
388 h += getDefaultPort();
389 else
390 h += u.getPort();
391
392 // Generate the ref part.
393 String ref = u.getRef();
394 if (ref != null)
395 h += ref.hashCode();
396
397 return h;
398 }
399
400 /**
401 * Compare two urls to see whether they refer to the same file,
402 * i.e., having the same protocol, host, port, and path.
403 * This method requires that none of its arguments is null. This is
404 * guaranteed by the fact that it is only called indirectly
405 * by java.net.URL class.
406 * @param u1 a URL object
407 * @param u2 a URL object
408 * @return true if u1 and u2 refer to the same file
409 * @since 1.3
410 */
411 protected boolean sameFile(URL u1, URL u2) {
412 // Compare the protocols.
413 if (!((u1.getProtocol() == u2.getProtocol()) ||
414 (u1.getProtocol() != null &&
415 u1.getProtocol().equalsIgnoreCase(u2.getProtocol()))))
416 return false;
417
418 // Compare the files.
419 if (!(u1.getFile() == u2.getFile() ||
420 (u1.getFile() != null && u1.getFile().equals(u2.getFile()))))
421 return false;
422
423 // Compare the ports.
424 int port1, port2;
425 port1 = (u1.getPort() != -1) ? u1.getPort() : u1.handler.getDefaultPort();
426 port2 = (u2.getPort() != -1) ? u2.getPort() : u2.handler.getDefaultPort();
427 if (port1 != port2)
428 return false;
429
430 // Compare the hosts.
431 if (!hostsEqual(u1, u2))
432 return false;
433
434 return true;
435 }
436
437 /**
438 * Get the IP address of our host. An empty host field or a DNS failure
439 * will result in a null return.
440 *
441 * @param u a URL object
442 * @return an {@code InetAddress} representing the host
443 * IP address.
444 * @since 1.3
445 */
446 protected synchronized InetAddress getHostAddress(URL u) {
447 if (u.hostAddress != null)
448 return u.hostAddress;
449
450 String host = u.getHost();
451 if (host == null || host.isEmpty()) {
452 return null;
453 } else {
454 try {
455 u.hostAddress = InetAddress.getByName(host);
456 } catch (UnknownHostException ex) {
457 return null;
458 } catch (SecurityException se) {
459 return null;
460 }
461 }
462 return u.hostAddress;
463 }
464
465 /**
466 * Compares the host components of two URLs.
467 * @param u1 the URL of the first host to compare
468 * @param u2 the URL of the second host to compare
469 * @return {@code true} if and only if they
470 * are equal, {@code false} otherwise.
471 * @since 1.3
472 */
473 protected boolean hostsEqual(URL u1, URL u2) {
474 InetAddress a1 = getHostAddress(u1);
475 InetAddress a2 = getHostAddress(u2);
476 // if we have internet address for both, compare them
477 if (a1 != null && a2 != null) {
478 return a1.equals(a2);
479 // else, if both have host names, compare them
480 } else if (u1.getHost() != null && u2.getHost() != null)
481 return u1.getHost().equalsIgnoreCase(u2.getHost());
482 else
483 return u1.getHost() == null && u2.getHost() == null;
484 }
485
486 /**
487 * Converts a {@code URL} of a specific protocol to a
488 * {@code String}.
489 *
490 * @param u the URL.
491 * @return a string representation of the {@code URL} argument.
492 */
493 protected String toExternalForm(URL u) {
494 String s;
495 return u.getProtocol()
496 + ':'
497 + ((s = u.getAuthority()) != null && !s.isEmpty()
498 ? "//" + s : "")
499 + ((s = u.getPath()) != null ? s : "")
500 + ((s = u.getQuery()) != null ? '?' + s : "")
501 + ((s = u.getRef()) != null ? '#' + s : "");
502 }
503
504 /**
505 * Sets the fields of the {@code URL} argument to the indicated values.
506 * Only classes derived from URLStreamHandler are able
507 * to use this method to set the values of the URL fields.
508 *
509 * @param u the URL to modify.
510 * @param protocol the protocol name.
511 * @param host the remote host value for the URL.
512 * @param port the port on the remote machine.
513 * @param authority the authority part for the URL.
514 * @param userInfo the userInfo part of the URL.
515 * @param path the path component of the URL.
516 * @param query the query part for the URL.
517 * @param ref the reference.
518 * @throws SecurityException if the protocol handler of the URL is
519 * different from this one
520 * @since 1.3
521 */
522 protected void setURL(URL u, String protocol, String host, int port,
523 String authority, String userInfo, String path,
524 String query, String ref) {
525 if (this != u.handler) {
526 throw new SecurityException("handler for url different from " +
527 "this handler");
528 } else if (host != null && u.isBuiltinStreamHandler(this)) {
529 String s = IPAddressUtil.checkHostString(host);
530 if (s != null) throw new IllegalArgumentException(s);
531 }
532 // ensure that no one can reset the protocol on a given URL.
533 u.set(u.getProtocol(), host, port, authority, userInfo, path, query, ref);
534 }
535
536 /**
537 * Sets the fields of the {@code URL} argument to the indicated values.
538 * Only classes derived from URLStreamHandler are able
539 * to use this method to set the values of the URL fields.
540 *
541 * @param u the URL to modify.
542 * @param protocol the protocol name. This value is ignored since 1.2.
543 * @param host the remote host value for the URL.
544 * @param port the port on the remote machine.
545 * @param file the file.
546 * @param ref the reference.
547 * @throws SecurityException if the protocol handler of the URL is
548 * different from this one
549 * @deprecated Use setURL(URL, String, String, int, String, String, String,
550 * String);
551 */
552 @Deprecated
553 protected void setURL(URL u, String protocol, String host, int port,
554 String file, String ref) {
555 /*
556 * Only old URL handlers call this, so assume that the host
557 * field might contain "user:passwd@host". Fix as necessary.
558 */
559 String authority = null;
560 String userInfo = null;
561 if (host != null && !host.isEmpty()) {
562 authority = (port == -1) ? host : host + ":" + port;
563 int at = host.lastIndexOf('@');
564 if (at != -1) {
565 userInfo = host.substring(0, at);
566 host = host.substring(at+1);
567 }
568 }
569
570 /*
571 * Assume file might contain query part. Fix as necessary.
572 */
573 String path = null;
574 String query = null;
575 if (file != null) {
576 int q = file.lastIndexOf('?');
577 if (q != -1) {
578 query = file.substring(q+1);
579 path = file.substring(0, q);
580 } else
581 path = file;
582 }
583 setURL(u, protocol, host, port, authority, userInfo, path, query, ref);
584 }
585 }