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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