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 * Opens a connection to the object referenced by the
56 * {@code URL} argument.
57 * This method should be overridden by a subclass.
58 *
59 * <p>If for the handler's protocol (such as HTTP or JAR), there
60 * exists a public, specialized URLConnection subclass belonging
61 * to one of the following packages or one of their subpackages:
62 * java.lang, java.io, java.util, java.net, the connection
63 * returned will be of that subclass. For example, for HTTP an
64 * HttpURLConnection will be returned, and for JAR a
65 * JarURLConnection will be returned.
66 *
67 * @param u the URL that this connects to.
68 * @return a {@code URLConnection} object for the {@code URL}.
69 * @exception IOException if an I/O error occurs while opening the
70 * connection.
71 */
72 protected abstract URLConnection openConnection(URL u) throws IOException;
73
74 /**
75 * Same as openConnection(URL), except that the connection will be
76 * made through the specified proxy; Protocol handlers that do not
77 * support proxying will ignore the proxy parameter and make a
78 * normal connection.
79 *
80 * <p> Calling this method preempts the system's default
81 * {@link java.net.ProxySelector ProxySelector} settings.
82 *
83 * @implSpec
84 * The default implementation of this method first checks that the given
85 * {@code URL} and {@code Proxy} are not null, then throws {@code
86 * UnsupportedOperationException}. Subclasses should override this method
87 * with an appropriate implementation.
88 *
89 * @param u the URL that this connects to.
90 * @param p the proxy through which the connection will be made.
91 * If direct connection is desired, Proxy.NO_PROXY
92 * should be specified.
93 * @return a {@code URLConnection} object for the {@code URL}.
94 * @exception IOException if an I/O error occurs while opening the
95 * connection.
96 * @exception IllegalArgumentException if either u or p is null,
97 * or p has the wrong type.
98 * @exception UnsupportedOperationException if the subclass that
99 * implements the protocol doesn't support this method.
100 * @since 1.5
101 */
102 protected URLConnection openConnection(URL u, Proxy p) throws IOException {
103 if (u == null || p == null)
104 throw new IllegalArgumentException("null " + (u == null ? "url" : "proxy"));
105 throw new UnsupportedOperationException("Method not implemented.");
106 }
107
108 /**
109 * Parses the string representation of a {@code URL} into a
110 * {@code URL} object.
111 * <p>
112 * If there is any inherited context, then it has already been
113 * copied into the {@code URL} argument.
114 * <p>
115 * The {@code parseURL} method of {@code URLStreamHandler}
116 * parses the string representation as if it were an
117 * {@code http} specification. Most URL protocol families have a
118 * similar parsing. A stream protocol handler for a protocol that has
119 * a different syntax must override this routine.
120 *
121 * @param u the {@code URL} to receive the result of parsing
122 * the spec.
123 * @param spec the {@code String} representing the URL that
124 * must be parsed.
125 * @param start the character index at which to begin parsing. This is
126 * just past the '{@code :}' (if there is one) that
127 * specifies the determination of the protocol name.
128 * @param limit the character position to stop parsing at. This is the
129 * end of the string or the position of the
130 * "{@code #}" character, if present. All information
131 * after the sharp sign indicates an anchor.
132 */
133 protected void parseURL(URL u, String spec, int start, int limit) {
134 // These fields may receive context content if this was relative URL
135 String protocol = u.getProtocol();
136 String authority = u.getAuthority();
137 String userInfo = u.getUserInfo();
138 String host = u.getHost();
139 int port = u.getPort();
140 String path = u.getPath();
141 String query = u.getQuery();
142
143 // This field has already been parsed
144 String ref = u.getRef();
145
146 boolean isRelPath = false;
147 boolean queryOnly = false;
148
149 // FIX: should not assume query if opaque
150 // Strip off the query part
151 if (start < limit) {
152 int queryStart = spec.indexOf('?');
153 queryOnly = queryStart == start;
154 if ((queryStart != -1) && (queryStart < limit)) {
155 query = spec.substring(queryStart+1, limit);
156 if (limit > queryStart)
157 limit = queryStart;
158 spec = spec.substring(0, queryStart);
159 }
160 }
161
162 int i = 0;
163 // Parse the authority part if any
164 boolean isUNCName = (start <= limit - 4) &&
165 (spec.charAt(start) == '/') &&
166 (spec.charAt(start + 1) == '/') &&
167 (spec.charAt(start + 2) == '/') &&
168 (spec.charAt(start + 3) == '/');
169 if (!isUNCName && (start <= limit - 2) && (spec.charAt(start) == '/') &&
170 (spec.charAt(start + 1) == '/')) {
171 start += 2;
172 i = spec.indexOf('/', start);
173 if (i < 0 || i > limit) {
174 i = spec.indexOf('?', start);
175 if (i < 0 || i > limit)
176 i = limit;
177 }
178
179 host = authority = spec.substring(start, i);
180
181 int ind = authority.indexOf('@');
182 if (ind != -1) {
183 if (ind != authority.lastIndexOf('@')) {
184 // more than one '@' in authority. This is not server based
185 userInfo = null;
186 host = null;
187 } else {
188 userInfo = authority.substring(0, ind);
189 host = authority.substring(ind+1);
190 }
191 } else {
192 userInfo = null;
193 }
194 if (host != null) {
195 // If the host is surrounded by [ and ] then its an IPv6
196 // literal address as specified in RFC2732
197 if (host.length()>0 && (host.charAt(0) == '[')) {
198 if ((ind = host.indexOf(']')) > 2) {
199
200 String nhost = host ;
201 host = nhost.substring(0,ind+1);
202 if (!IPAddressUtil.
203 isIPv6LiteralAddress(host.substring(1, ind))) {
204 throw new IllegalArgumentException(
205 "Invalid host: "+ host);
206 }
207
208 port = -1 ;
209 if (nhost.length() > ind+1) {
210 if (nhost.charAt(ind+1) == ':') {
211 ++ind ;
212 // port can be null according to RFC2396
213 if (nhost.length() > (ind + 1)) {
214 port = Integer.parseInt(nhost, ind + 1,
215 nhost.length(), 10);
216 }
217 } else {
218 throw new IllegalArgumentException(
219 "Invalid authority field: " + authority);
220 }
221 }
222 } else {
223 throw new IllegalArgumentException(
224 "Invalid authority field: " + authority);
225 }
226 } else {
227 ind = host.indexOf(':');
228 port = -1;
229 if (ind >= 0) {
230 // port can be null according to RFC2396
231 if (host.length() > (ind + 1)) {
232 port = Integer.parseInt(host, ind + 1,
233 host.length(), 10);
234 }
235 host = host.substring(0, ind);
236 }
237 }
238 } else {
239 host = "";
240 }
241 if (port < -1)
242 throw new IllegalArgumentException("Invalid port number :" +
243 port);
244 start = i;
245 // If the authority is defined then the path is defined by the
246 // spec only; See RFC 2396 Section 5.2.4.
247 if (authority != null && !authority.isEmpty())
248 path = "";
249 }
250
251 if (host == null) {
252 host = "";
253 }
254
255 // Parse the file path if any
256 if (start < limit) {
257 if (spec.charAt(start) == '/') {
258 path = spec.substring(start, limit);
259 } else if (path != null && !path.isEmpty()) {
260 isRelPath = true;
261 int ind = path.lastIndexOf('/');
262 String separator = "";
263 if (ind == -1 && authority != null)
264 separator = "/";
265 path = path.substring(0, ind + 1) + separator +
266 spec.substring(start, limit);
267
268 } else {
269 String separator = (authority != null) ? "/" : "";
270 path = separator + spec.substring(start, limit);
271 }
272 } else if (queryOnly && path != null) {
273 int ind = path.lastIndexOf('/');
274 if (ind < 0)
275 ind = 0;
276 path = path.substring(0, ind) + "/";
277 }
278 if (path == null)
279 path = "";
280
281 if (isRelPath) {
282 // Remove embedded /./
283 while ((i = path.indexOf("/./")) >= 0) {
284 path = path.substring(0, i) + path.substring(i + 2);
285 }
286 // Remove embedded /../ if possible
287 i = 0;
288 while ((i = path.indexOf("/../", i)) >= 0) {
289 /*
290 * A "/../" will cancel the previous segment and itself,
291 * unless that segment is a "/../" itself
292 * i.e. "/a/b/../c" becomes "/a/c"
293 * but "/../../a" should stay unchanged
294 */
295 if (i > 0 && (limit = path.lastIndexOf('/', i - 1)) >= 0 &&
296 (path.indexOf("/../", limit) != 0)) {
297 path = path.substring(0, limit) + path.substring(i + 3);
298 i = 0;
299 } else {
300 i = i + 3;
301 }
302 }
303 // Remove trailing .. if possible
304 while (path.endsWith("/..")) {
305 i = path.indexOf("/..");
306 if ((limit = path.lastIndexOf('/', i - 1)) >= 0) {
307 path = path.substring(0, limit+1);
308 } else {
309 break;
310 }
311 }
312 // Remove starting .
313 if (path.startsWith("./") && path.length() > 2)
314 path = path.substring(2);
315
316 // Remove trailing .
317 if (path.endsWith("/."))
318 path = path.substring(0, path.length() -1);
319 }
320
321 setURL(u, protocol, host, port, authority, userInfo, path, query, ref);
322 }
323
324 /**
325 * Returns the default port for a URL parsed by this handler. This method
326 * is meant to be overridden by handlers with default port numbers.
327 * @return the default port for a {@code URL} parsed by this handler.
328 * @since 1.3
329 */
330 protected int getDefaultPort() {
331 return -1;
332 }
333
334 /**
335 * Provides the default equals calculation. May be overridden by handlers
336 * for other protocols that have different requirements for equals().
337 * This method requires that none of its arguments is null. This is
338 * guaranteed by the fact that it is only called by java.net.URL class.
339 * @param u1 a URL object
340 * @param u2 a URL object
341 * @return {@code true} if the two urls are
342 * considered equal, i.e. they refer to the same
343 * fragment in the same file.
344 * @since 1.3
345 */
346 protected boolean equals(URL u1, URL u2) {
347 return Objects.equals(u1.getRef(), u2.getRef()) && sameFile(u1, u2);
348 }
349
350 /**
351 * Provides the default hash calculation. May be overridden by handlers for
352 * other protocols that have different requirements for hashCode
353 * calculation.
354 * @param u a URL object
355 * @return an {@code int} suitable for hash table indexing
356 * @since 1.3
357 */
358 protected int hashCode(URL u) {
359 int h = 0;
360
361 // Generate the protocol part.
362 String protocol = u.getProtocol();
363 if (protocol != null)
364 h += protocol.hashCode();
365
366 // Generate the host part.
367 InetAddress addr = getHostAddress(u);
368 if (addr != null) {
369 h += addr.hashCode();
370 } else {
371 String host = u.getHost();
372 if (host != null)
373 h += host.toLowerCase().hashCode();
374 }
375
376 // Generate the file part.
377 String file = u.getFile();
378 if (file != null)
379 h += file.hashCode();
380
381 // Generate the port part.
382 if (u.getPort() == -1)
383 h += getDefaultPort();
384 else
385 h += u.getPort();
386
387 // Generate the ref part.
388 String ref = u.getRef();
389 if (ref != null)
390 h += ref.hashCode();
391
392 return h;
393 }
394
395 /**
396 * Compare two urls to see whether they refer to the same file,
397 * i.e., having the same protocol, host, port, and path.
398 * This method requires that none of its arguments is null. This is
399 * guaranteed by the fact that it is only called indirectly
400 * by java.net.URL class.
401 * @param u1 a URL object
402 * @param u2 a URL object
403 * @return true if u1 and u2 refer to the same file
404 * @since 1.3
405 */
406 protected boolean sameFile(URL u1, URL u2) {
407 // Compare the protocols.
408 if (!((u1.getProtocol() == u2.getProtocol()) ||
409 (u1.getProtocol() != null &&
410 u1.getProtocol().equalsIgnoreCase(u2.getProtocol()))))
411 return false;
412
413 // Compare the files.
414 if (!(u1.getFile() == u2.getFile() ||
415 (u1.getFile() != null && u1.getFile().equals(u2.getFile()))))
416 return false;
417
418 // Compare the ports.
419 int port1, port2;
420 port1 = (u1.getPort() != -1) ? u1.getPort() : u1.handler.getDefaultPort();
421 port2 = (u2.getPort() != -1) ? u2.getPort() : u2.handler.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} 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.isEmpty()) {
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 {@code true} if and only if they
465 * are equal, {@code false} 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} of a specific protocol to a
483 * {@code String}.
484 *
485 * @param u the URL.
486 * @return a string representation of the {@code URL} argument.
487 */
488 protected String toExternalForm(URL u) {
489 String s;
490 return u.getProtocol()
491 + ':'
492 + ((s = u.getAuthority()) != null && !s.isEmpty()
493 ? "//" + s : "")
494 + ((s = u.getPath()) != null ? s : "")
495 + ((s = u.getQuery()) != null ? '?' + s : "")
496 + ((s = u.getRef()) != null ? '#' + s : "");
497 }
498
499 /**
500 * Sets the fields of the {@code URL} argument to the indicated values.
501 * Only classes derived from URLStreamHandler are able
502 * to use this method to set the values of the URL fields.
503 *
504 * @param u the URL to modify.
505 * @param protocol the protocol name.
506 * @param host the remote host value for the URL.
507 * @param port the port on the remote machine.
508 * @param authority the authority part for the URL.
509 * @param userInfo the userInfo part of the URL.
510 * @param path the path component of the URL.
511 * @param query the query part for the URL.
512 * @param ref the reference.
513 * @exception SecurityException if the protocol handler of the URL is
514 * different from this one
515 * @since 1.3
516 */
517 protected void setURL(URL u, String protocol, String host, int port,
518 String authority, String userInfo, String path,
519 String query, String ref) {
520 if (this != u.handler) {
521 throw new SecurityException("handler for url different from " +
522 "this handler");
523 } else if (host != null && u.isBuiltinStreamHandler(this)) {
524 String s = IPAddressUtil.checkHostString(host);
525 if (s != null) throw new IllegalArgumentException(s);
526 }
527 // ensure that no one can reset the protocol on a given URL.
528 u.set(u.getProtocol(), host, port, authority, userInfo, path, query, ref);
529 }
530
531 /**
532 * Sets the fields of the {@code URL} argument to the indicated values.
533 * Only classes derived from URLStreamHandler are able
534 * to use this method to set the values of the URL fields.
535 *
536 * @param u the URL to modify.
537 * @param protocol the protocol name. This value is ignored since 1.2.
538 * @param host the remote host value for the URL.
539 * @param port the port on the remote machine.
540 * @param file the file.
541 * @param ref the reference.
542 * @exception SecurityException if the protocol handler of the URL is
543 * different from this one
544 * @deprecated Use setURL(URL, String, String, int, String, String, String,
545 * String);
546 */
547 @Deprecated
548 protected void setURL(URL u, String protocol, String host, int port,
549 String file, String ref) {
550 /*
551 * Only old URL handlers call this, so assume that the host
552 * field might contain "user:passwd@host". Fix as necessary.
553 */
554 String authority = null;
555 String userInfo = null;
556 if (host != null && !host.isEmpty()) {
557 authority = (port == -1) ? host : host + ":" + port;
558 int at = host.lastIndexOf('@');
559 if (at != -1) {
560 userInfo = host.substring(0, at);
561 host = host.substring(at+1);
562 }
563 }
564
565 /*
566 * Assume file might contain query part. Fix as necessary.
567 */
568 String path = null;
569 String query = null;
570 if (file != null) {
571 int q = file.lastIndexOf('?');
572 if (q != -1) {
573 query = file.substring(q+1);
574 path = file.substring(0, q);
575 } else
576 path = file;
577 }
578 setURL(u, protocol, host, port, authority, userInfo, path, query, ref);
579 }
580 }