1 /*
2 * Copyright (c) 1996, 2010, 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.InputStream;
29 import java.io.IOException;
30 import java.security.Permission;
31 import java.util.Date;
32
33 /**
34 * A URLConnection with support for HTTP-specific features. See
35 * <A HREF="http://www.w3.org/pub/WWW/Protocols/"> the spec </A> for
36 * details.
37 * <p>
38 *
39 * Each HttpURLConnection instance is used to make a single request
40 * but the underlying network connection to the HTTP server may be
41 * transparently shared by other instances. Calling the close() methods
42 * on the InputStream or OutputStream of an HttpURLConnection
43 * after a request may free network resources associated with this
44 * instance but has no effect on any shared persistent connection.
45 * Calling the disconnect() method may close the underlying socket
46 * if a persistent connection is otherwise idle at that time.
47 *
48 * @see java.net.HttpURLConnection#disconnect()
49 * @since JDK1.1
50 */
51 abstract public class HttpURLConnection extends URLConnection {
52 /* instance variables */
53
54 /**
55 * The HTTP method (GET,POST,PUT,etc.).
56 */
57 protected String method = "GET";
58
59 /**
60 * The chunk-length when using chunked encoding streaming mode for output.
61 * A value of <code>-1</code> means chunked encoding is disabled for output.
62 * @since 1.5
63 */
64 protected int chunkLength = -1;
65
66 /**
67 * The fixed content-length when using fixed-length streaming mode.
68 * A value of <code>-1</code> means fixed-length streaming mode is disabled
69 * for output.
70 * @since 1.5
71 */
72 protected int fixedContentLength = -1;
73
74 /**
75 * Returns the key for the <code>n</code><sup>th</sup> header field.
76 * Some implementations may treat the <code>0</code><sup>th</sup>
77 * header field as special, i.e. as the status line returned by the HTTP
78 * server. In this case, {@link #getHeaderField(int) getHeaderField(0)} returns the status
79 * line, but <code>getHeaderFieldKey(0)</code> returns null.
80 *
81 * @param n an index, where n >=0.
82 * @return the key for the <code>n</code><sup>th</sup> header field,
83 * or <code>null</code> if the key does not exist.
84 */
85 public String getHeaderFieldKey (int n) {
86 return null;
87 }
88
89 /**
90 * This method is used to enable streaming of a HTTP request body
91 * without internal buffering, when the content length is known in
92 * advance.
93 * <p>
94 * An exception will be thrown if the application
95 * attempts to write more data than the indicated
96 * content-length, or if the application closes the OutputStream
97 * before writing the indicated amount.
98 * <p>
99 * When output streaming is enabled, authentication
100 * and redirection cannot be handled automatically.
101 * A HttpRetryException will be thrown when reading
102 * the response if authentication or redirection are required.
103 * This exception can be queried for the details of the error.
104 * <p>
105 * This method must be called before the URLConnection is connected.
106 *
107 * @param contentLength The number of bytes which will be written
108 * to the OutputStream.
109 *
110 * @throws IllegalStateException if URLConnection is already connected
111 * or if a different streaming mode is already enabled.
112 *
113 * @throws IllegalArgumentException if a content length less than
114 * zero is specified.
115 *
116 * @see #setChunkedStreamingMode(int)
117 * @since 1.5
118 */
119 public void setFixedLengthStreamingMode (int contentLength) {
120 if (connected) {
121 throw new IllegalStateException ("Already connected");
122 }
123 if (chunkLength != -1) {
124 throw new IllegalStateException ("Chunked encoding streaming mode set");
125 }
126 if (contentLength < 0) {
127 throw new IllegalArgumentException ("invalid content length");
128 }
129 fixedContentLength = contentLength;
130 }
131
132 /* Default chunk size (including chunk header) if not specified;
133 * we want to keep this in sync with the one defined in
134 * sun.net.www.http.ChunkedOutputStream
135 */
136 private static final int DEFAULT_CHUNK_SIZE = 4096;
137
138 /**
139 * This method is used to enable streaming of a HTTP request body
140 * without internal buffering, when the content length is <b>not</b>
141 * known in advance. In this mode, chunked transfer encoding
142 * is used to send the request body. Note, not all HTTP servers
143 * support this mode.
144 * <p>
145 * When output streaming is enabled, authentication
146 * and redirection cannot be handled automatically.
147 * A HttpRetryException will be thrown when reading
148 * the response if authentication or redirection are required.
149 * This exception can be queried for the details of the error.
150 * <p>
151 * This method must be called before the URLConnection is connected.
152 *
153 * @param chunklen The number of bytes to write in each chunk.
154 * If chunklen is less than or equal to zero, a default
155 * value will be used.
156 *
157 * @throws IllegalStateException if URLConnection is already connected
158 * or if a different streaming mode is already enabled.
159 *
160 * @see #setFixedLengthStreamingMode(int)
161 * @since 1.5
162 */
163 public void setChunkedStreamingMode (int chunklen) {
164 if (connected) {
165 throw new IllegalStateException ("Can't set streaming mode: already connected");
166 }
167 if (fixedContentLength != -1) {
168 throw new IllegalStateException ("Fixed length streaming mode set");
169 }
170 chunkLength = chunklen <=0? DEFAULT_CHUNK_SIZE : chunklen;
171 }
172
173 /**
174 * Returns the value for the <code>n</code><sup>th</sup> header field.
175 * Some implementations may treat the <code>0</code><sup>th</sup>
176 * header field as special, i.e. as the status line returned by the HTTP
177 * server.
178 * <p>
179 * This method can be used in conjunction with the
180 * {@link #getHeaderFieldKey getHeaderFieldKey} method to iterate through all
181 * the headers in the message.
182 *
183 * @param n an index, where n>=0.
184 * @return the value of the <code>n</code><sup>th</sup> header field,
185 * or <code>null</code> if the value does not exist.
186 * @see java.net.HttpURLConnection#getHeaderFieldKey(int)
187 */
188 public String getHeaderField(int n) {
189 return null;
190 }
191
192 /**
193 * An <code>int</code> representing the three digit HTTP Status-Code.
194 * <ul>
195 * <li> 1xx: Informational
196 * <li> 2xx: Success
197 * <li> 3xx: Redirection
198 * <li> 4xx: Client Error
199 * <li> 5xx: Server Error
200 * </ul>
201 */
202 protected int responseCode = -1;
203
204 /**
205 * The HTTP response message.
206 */
207 protected String responseMessage = null;
208
209 /* static variables */
210
211 /* do we automatically follow redirects? The default is true. */
212 private static boolean followRedirects = true;
213
214 /**
215 * If <code>true</code>, the protocol will automatically follow redirects.
216 * If <code>false</code>, the protocol will not automatically follow
217 * redirects.
218 * <p>
219 * This field is set by the <code>setInstanceFollowRedirects</code>
220 * method. Its value is returned by the <code>getInstanceFollowRedirects</code>
221 * method.
222 * <p>
223 * Its default value is based on the value of the static followRedirects
224 * at HttpURLConnection construction time.
225 *
226 * @see java.net.HttpURLConnection#setInstanceFollowRedirects(boolean)
227 * @see java.net.HttpURLConnection#getInstanceFollowRedirects()
228 * @see java.net.HttpURLConnection#setFollowRedirects(boolean)
229 */
230 protected boolean instanceFollowRedirects = followRedirects;
231
232 /* valid HTTP methods */
233 private static final String[] methods = {
234 "GET", "POST", "HEAD", "OPTIONS", "PUT", "DELETE", "TRACE"
235 };
236
237 /**
238 * Constructor for the HttpURLConnection.
239 * @param u the URL
240 */
241 protected HttpURLConnection (URL u) {
242 super(u);
243 }
244
245 /**
246 * Sets whether HTTP redirects (requests with response code 3xx) should
247 * be automatically followed by this class. True by default. Applets
248 * cannot change this variable.
249 * <p>
250 * If there is a security manager, this method first calls
251 * the security manager's <code>checkSetFactory</code> method
252 * to ensure the operation is allowed.
253 * This could result in a SecurityException.
254 *
255 * @param set a <code>boolean</code> indicating whether or not
256 * to follow HTTP redirects.
257 * @exception SecurityException if a security manager exists and its
258 * <code>checkSetFactory</code> method doesn't
259 * allow the operation.
260 * @see SecurityManager#checkSetFactory
261 * @see #getFollowRedirects()
262 */
263 public static void setFollowRedirects(boolean set) {
264 SecurityManager sec = System.getSecurityManager();
265 if (sec != null) {
266 // seems to be the best check here...
267 sec.checkSetFactory();
268 }
269 followRedirects = set;
270 }
271
272 /**
273 * Returns a <code>boolean</code> indicating
274 * whether or not HTTP redirects (3xx) should
275 * be automatically followed.
276 *
277 * @return <code>true</code> if HTTP redirects should
278 * be automatically followed, <tt>false</tt> if not.
279 * @see #setFollowRedirects(boolean)
280 */
281 public static boolean getFollowRedirects() {
282 return followRedirects;
283 }
284
285 /**
286 * Sets whether HTTP redirects (requests with response code 3xx) should
287 * be automatically followed by this <code>HttpURLConnection</code>
288 * instance.
289 * <p>
290 * The default value comes from followRedirects, which defaults to
291 * true.
292 *
293 * @param followRedirects a <code>boolean</code> indicating
294 * whether or not to follow HTTP redirects.
295 *
296 * @see java.net.HttpURLConnection#instanceFollowRedirects
297 * @see #getInstanceFollowRedirects
298 * @since 1.3
299 */
300 public void setInstanceFollowRedirects(boolean followRedirects) {
301 instanceFollowRedirects = followRedirects;
302 }
303
304 /**
305 * Returns the value of this <code>HttpURLConnection</code>'s
306 * <code>instanceFollowRedirects</code> field.
307 *
308 * @return the value of this <code>HttpURLConnection</code>'s
309 * <code>instanceFollowRedirects</code> field.
310 * @see java.net.HttpURLConnection#instanceFollowRedirects
311 * @see #setInstanceFollowRedirects(boolean)
312 * @since 1.3
313 */
314 public boolean getInstanceFollowRedirects() {
315 return instanceFollowRedirects;
316 }
317
318 /**
319 * Set the method for the URL request, one of:
320 * <UL>
321 * <LI>GET
322 * <LI>POST
323 * <LI>HEAD
324 * <LI>OPTIONS
325 * <LI>PUT
326 * <LI>DELETE
327 * <LI>TRACE
328 * </UL> are legal, subject to protocol restrictions. The default
329 * method is GET.
330 *
331 * @param method the HTTP method
332 * @exception ProtocolException if the method cannot be reset or if
333 * the requested method isn't valid for HTTP.
334 * @see #getRequestMethod()
335 */
336 public void setRequestMethod(String method) throws ProtocolException {
337 if (connected) {
338 throw new ProtocolException("Can't reset method: already connected");
339 }
340 // This restriction will prevent people from using this class to
341 // experiment w/ new HTTP methods using java. But it should
342 // be placed for security - the request String could be
343 // arbitrarily long.
344
345 for (int i = 0; i < methods.length; i++) {
346 if (methods[i].equals(method)) {
347 if (method.equals("TRACE")) {
348 SecurityManager s = System.getSecurityManager();
349 if (s != null) {
350 s.checkPermission(new NetPermission("allowHttpTrace"));
351 }
352 }
353 this.method = method;
354 return;
355 }
356 }
357 throw new ProtocolException("Invalid HTTP method: " + method);
358 }
359
360 /**
361 * Get the request method.
362 * @return the HTTP request method
363 * @see #setRequestMethod(java.lang.String)
364 */
365 public String getRequestMethod() {
366 return method;
367 }
368
369 /**
370 * Gets the status code from an HTTP response message.
371 * For example, in the case of the following status lines:
372 * <PRE>
373 * HTTP/1.0 200 OK
374 * HTTP/1.0 401 Unauthorized
375 * </PRE>
376 * It will return 200 and 401 respectively.
377 * Returns -1 if no code can be discerned
378 * from the response (i.e., the response is not valid HTTP).
379 * @throws IOException if an error occurred connecting to the server.
380 * @return the HTTP Status-Code, or -1
381 */
382 public int getResponseCode() throws IOException {
383 /*
384 * We're got the response code already
385 */
386 if (responseCode != -1) {
387 return responseCode;
388 }
389
390 /*
391 * Ensure that we have connected to the server. Record
392 * exception as we need to re-throw it if there isn't
393 * a status line.
394 */
395 Exception exc = null;
396 try {
397 getInputStream();
398 } catch (Exception e) {
399 exc = e;
400 }
401
402 /*
403 * If we can't a status-line then re-throw any exception
404 * that getInputStream threw.
405 */
406 String statusLine = getHeaderField(0);
407 if (statusLine == null) {
408 if (exc != null) {
409 if (exc instanceof RuntimeException)
410 throw (RuntimeException)exc;
411 else
412 throw (IOException)exc;
413 }
414 return -1;
415 }
416
417 /*
418 * Examine the status-line - should be formatted as per
419 * section 6.1 of RFC 2616 :-
420 *
421 * Status-Line = HTTP-Version SP Status-Code SP Reason-Phrase
422 *
423 * If status line can't be parsed return -1.
424 */
425 if (statusLine.startsWith("HTTP/1.")) {
426 int codePos = statusLine.indexOf(' ');
427 if (codePos > 0) {
428
429 int phrasePos = statusLine.indexOf(' ', codePos+1);
430 if (phrasePos > 0 && phrasePos < statusLine.length()) {
431 responseMessage = statusLine.substring(phrasePos+1);
432 }
433
434 // deviation from RFC 2616 - don't reject status line
435 // if SP Reason-Phrase is not included.
436 if (phrasePos < 0)
437 phrasePos = statusLine.length();
438
439 try {
440 responseCode = Integer.parseInt
441 (statusLine.substring(codePos+1, phrasePos));
442 return responseCode;
443 } catch (NumberFormatException e) { }
444 }
445 }
446 return -1;
447 }
448
449 /**
450 * Gets the HTTP response message, if any, returned along with the
451 * response code from a server. From responses like:
452 * <PRE>
453 * HTTP/1.0 200 OK
454 * HTTP/1.0 404 Not Found
455 * </PRE>
456 * Extracts the Strings "OK" and "Not Found" respectively.
457 * Returns null if none could be discerned from the responses
458 * (the result was not valid HTTP).
459 * @throws IOException if an error occurred connecting to the server.
460 * @return the HTTP response message, or <code>null</code>
461 */
462 public String getResponseMessage() throws IOException {
463 getResponseCode();
464 return responseMessage;
465 }
466
467 @SuppressWarnings("deprecation")
468 public long getHeaderFieldDate(String name, long Default) {
469 String dateString = getHeaderField(name);
470 try {
471 if (dateString.indexOf("GMT") == -1) {
472 dateString = dateString+" GMT";
473 }
474 return Date.parse(dateString);
475 } catch (Exception e) {
476 }
477 return Default;
478 }
479
480
481 /**
482 * Indicates that other requests to the server
483 * are unlikely in the near future. Calling disconnect()
484 * should not imply that this HttpURLConnection
485 * instance can be reused for other requests.
486 */
487 public abstract void disconnect();
488
489 /**
490 * Indicates if the connection is going through a proxy.
491 * @return a boolean indicating if the connection is
492 * using a proxy.
493 */
494 public abstract boolean usingProxy();
495
496 public Permission getPermission() throws IOException {
497 int port = url.getPort();
498 port = port < 0 ? 80 : port;
499 String host = url.getHost() + ":" + port;
500 Permission permission = new SocketPermission(host, "connect");
501 return permission;
502 }
503
504 /**
505 * Returns the error stream if the connection failed
506 * but the server sent useful data nonetheless. The
507 * typical example is when an HTTP server responds
508 * with a 404, which will cause a FileNotFoundException
509 * to be thrown in connect, but the server sent an HTML
510 * help page with suggestions as to what to do.
511 *
512 * <p>This method will not cause a connection to be initiated. If
513 * the connection was not connected, or if the server did not have
514 * an error while connecting or if the server had an error but
515 * no error data was sent, this method will return null. This is
516 * the default.
517 *
518 * @return an error stream if any, null if there have been no
519 * errors, the connection is not connected or the server sent no
520 * useful data.
521 */
522 public InputStream getErrorStream() {
523 return null;
524 }
525
526 /**
527 * The response codes for HTTP, as of version 1.1.
528 */
529
530 // REMIND: do we want all these??
531 // Others not here that we do want??
532
533 /* 2XX: generally "OK" */
534
535 /**
536 * HTTP Status-Code 200: OK.
537 */
538 public static final int HTTP_OK = 200;
539
540 /**
541 * HTTP Status-Code 201: Created.
542 */
543 public static final int HTTP_CREATED = 201;
544
545 /**
546 * HTTP Status-Code 202: Accepted.
547 */
548 public static final int HTTP_ACCEPTED = 202;
549
550 /**
551 * HTTP Status-Code 203: Non-Authoritative Information.
552 */
553 public static final int HTTP_NOT_AUTHORITATIVE = 203;
554
555 /**
556 * HTTP Status-Code 204: No Content.
557 */
558 public static final int HTTP_NO_CONTENT = 204;
559
560 /**
561 * HTTP Status-Code 205: Reset Content.
562 */
563 public static final int HTTP_RESET = 205;
564
565 /**
566 * HTTP Status-Code 206: Partial Content.
567 */
568 public static final int HTTP_PARTIAL = 206;
569
570 /* 3XX: relocation/redirect */
571
572 /**
573 * HTTP Status-Code 300: Multiple Choices.
574 */
575 public static final int HTTP_MULT_CHOICE = 300;
576
577 /**
578 * HTTP Status-Code 301: Moved Permanently.
579 */
580 public static final int HTTP_MOVED_PERM = 301;
581
582 /**
583 * HTTP Status-Code 302: Temporary Redirect.
584 */
585 public static final int HTTP_MOVED_TEMP = 302;
586
587 /**
588 * HTTP Status-Code 303: See Other.
589 */
590 public static final int HTTP_SEE_OTHER = 303;
591
592 /**
593 * HTTP Status-Code 304: Not Modified.
594 */
595 public static final int HTTP_NOT_MODIFIED = 304;
596
597 /**
598 * HTTP Status-Code 305: Use Proxy.
599 */
600 public static final int HTTP_USE_PROXY = 305;
601
602 /* 4XX: client error */
603
604 /**
605 * HTTP Status-Code 400: Bad Request.
606 */
607 public static final int HTTP_BAD_REQUEST = 400;
608
609 /**
610 * HTTP Status-Code 401: Unauthorized.
611 */
612 public static final int HTTP_UNAUTHORIZED = 401;
613
614 /**
615 * HTTP Status-Code 402: Payment Required.
616 */
617 public static final int HTTP_PAYMENT_REQUIRED = 402;
618
619 /**
620 * HTTP Status-Code 403: Forbidden.
621 */
622 public static final int HTTP_FORBIDDEN = 403;
623
624 /**
625 * HTTP Status-Code 404: Not Found.
626 */
627 public static final int HTTP_NOT_FOUND = 404;
628
629 /**
630 * HTTP Status-Code 405: Method Not Allowed.
631 */
632 public static final int HTTP_BAD_METHOD = 405;
633
634 /**
635 * HTTP Status-Code 406: Not Acceptable.
636 */
637 public static final int HTTP_NOT_ACCEPTABLE = 406;
638
639 /**
640 * HTTP Status-Code 407: Proxy Authentication Required.
641 */
642 public static final int HTTP_PROXY_AUTH = 407;
643
644 /**
645 * HTTP Status-Code 408: Request Time-Out.
646 */
647 public static final int HTTP_CLIENT_TIMEOUT = 408;
648
649 /**
650 * HTTP Status-Code 409: Conflict.
651 */
652 public static final int HTTP_CONFLICT = 409;
653
654 /**
655 * HTTP Status-Code 410: Gone.
656 */
657 public static final int HTTP_GONE = 410;
658
659 /**
660 * HTTP Status-Code 411: Length Required.
661 */
662 public static final int HTTP_LENGTH_REQUIRED = 411;
663
664 /**
665 * HTTP Status-Code 412: Precondition Failed.
666 */
667 public static final int HTTP_PRECON_FAILED = 412;
668
669 /**
670 * HTTP Status-Code 413: Request Entity Too Large.
671 */
672 public static final int HTTP_ENTITY_TOO_LARGE = 413;
673
674 /**
675 * HTTP Status-Code 414: Request-URI Too Large.
676 */
677 public static final int HTTP_REQ_TOO_LONG = 414;
678
679 /**
680 * HTTP Status-Code 415: Unsupported Media Type.
681 */
682 public static final int HTTP_UNSUPPORTED_TYPE = 415;
683
684 /* 5XX: server error */
685
686 /**
687 * HTTP Status-Code 500: Internal Server Error.
688 * @deprecated it is misplaced and shouldn't have existed.
689 */
690 @Deprecated
691 public static final int HTTP_SERVER_ERROR = 500;
692
693 /**
694 * HTTP Status-Code 500: Internal Server Error.
695 */
696 public static final int HTTP_INTERNAL_ERROR = 500;
697
698 /**
699 * HTTP Status-Code 501: Not Implemented.
700 */
701 public static final int HTTP_NOT_IMPLEMENTED = 501;
702
703 /**
704 * HTTP Status-Code 502: Bad Gateway.
705 */
706 public static final int HTTP_BAD_GATEWAY = 502;
707
708 /**
709 * HTTP Status-Code 503: Service Unavailable.
710 */
711 public static final int HTTP_UNAVAILABLE = 503;
712
713 /**
714 * HTTP Status-Code 504: Gateway Timeout.
715 */
716 public static final int HTTP_GATEWAY_TIMEOUT = 504;
717
718 /**
719 * HTTP Status-Code 505: HTTP Version Not Supported.
720 */
721 public static final int HTTP_VERSION = 505;
722
723 }