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      1 /*
      2  * Copyright (C) 2014 The Android Open Source Project
      3  * Copyright (c) 1995, 2013, Oracle and/or its affiliates. All rights reserved.
      4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
      5  *
      6  * This code is free software; you can redistribute it and/or modify it
      7  * under the terms of the GNU General Public License version 2 only, as
      8  * published by the Free Software Foundation.  Oracle designates this
      9  * particular file as subject to the "Classpath" exception as provided
     10  * by Oracle in the LICENSE file that accompanied this code.
     11  *
     12  * This code is distributed in the hope that it will be useful, but WITHOUT
     13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
     14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
     15  * version 2 for more details (a copy is included in the LICENSE file that
     16  * accompanied this code).
     17  *
     18  * You should have received a copy of the GNU General Public License version
     19  * 2 along with this work; if not, write to the Free Software Foundation,
     20  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
     21  *
     22  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
     23  * or visit www.oracle.com if you need additional information or have any
     24  * questions.
     25  */
     26 
     27 package java.net;
     28 
     29 import java.io.IOException;
     30 import java.util.Objects;
     31 
     32 import sun.net.util.IPAddressUtil;
     33 
     34 /**
     35  * The abstract class {@code URLStreamHandler} is the common
     36  * superclass for all stream protocol handlers. A stream protocol
     37  * handler knows how to make a connection for a particular protocol
     38  * type, such as {@code http} or {@code https}.
     39  * <p>
     40  * In most cases, an instance of a {@code URLStreamHandler}
     41  * subclass is not created directly by an application. Rather, the
     42  * first time a protocol name is encountered when constructing a
     43  * {@code URL}, the appropriate stream protocol handler is
     44  * automatically loaded.
     45  *
     46  * @author  James Gosling
     47  * @see     java.net.URL#URL(java.lang.String, java.lang.String, int, java.lang.String)
     48  * @since   JDK1.0
     49  */
     50 public abstract class URLStreamHandler {
     51     /**
     52      * Opens a connection to the object referenced by the
     53      * {@code URL} argument.
     54      * This method should be overridden by a subclass.
     55      *
     56      * <p>If for the handler's protocol (such as HTTP or JAR), there
     57      * exists a public, specialized URLConnection subclass belonging
     58      * to one of the following packages or one of their subpackages:
     59      * java.lang, java.io, java.util, java.net, the connection
     60      * returned will be of that subclass. For example, for HTTP an
     61      * HttpURLConnection will be returned, and for JAR a
     62      * JarURLConnection will be returned.
     63      *
     64      * @param      u   the URL that this connects to.
     65      * @return     a {@code URLConnection} object for the {@code URL}.
     66      * @exception  IOException  if an I/O error occurs while opening the
     67      *               connection.
     68      */
     69     abstract protected URLConnection openConnection(URL u) throws IOException;
     70 
     71     /**
     72      * Same as openConnection(URL), except that the connection will be
     73      * made through the specified proxy; Protocol handlers that do not
     74      * support proxying will ignore the proxy parameter and make a
     75      * normal connection.
     76      *
     77      * Calling this method preempts the system's default ProxySelector
     78      * settings.
     79      *
     80      * @param      u   the URL that this connects to.
     81      * @param      p   the proxy through which the connection will be made.
     82      *                 If direct connection is desired, Proxy.NO_PROXY
     83      *                 should be specified.
     84      * @return     a {@code URLConnection} object for the {@code URL}.
     85      * @exception  IOException  if an I/O error occurs while opening the
     86      *               connection.
     87      * @exception  IllegalArgumentException if either u or p is null,
     88      *               or p has the wrong type.
     89      * @exception  UnsupportedOperationException if the subclass that
     90      *               implements the protocol doesn't support this method.
     91      * @since      1.5
     92      */
     93     protected URLConnection openConnection(URL u, Proxy p) throws IOException {
     94         throw new UnsupportedOperationException("Method not implemented.");
     95     }
     96 
     97     /**
     98      * Parses the string representation of a {@code URL} into a
     99      * {@code URL} object.
    100      * <p>
    101      * If there is any inherited context, then it has already been
    102      * copied into the {@code URL} argument.
    103      * <p>
    104      * The {@code parseURL} method of {@code URLStreamHandler}
    105      * parses the string representation as if it were an
    106      * {@code http} specification. Most URL protocol families have a
    107      * similar parsing. A stream protocol handler for a protocol that has
    108      * a different syntax must override this routine.
    109      *
    110      * @param   u       the {@code URL} to receive the result of parsing
    111      *                  the spec.
    112      * @param   spec    the {@code String} representing the URL that
    113      *                  must be parsed.
    114      * @param   start   the character index at which to begin parsing. This is
    115      *                  just past the '{@code :}' (if there is one) that
    116      *                  specifies the determination of the protocol name.
    117      * @param   limit   the character position to stop parsing at. This is the
    118      *                  end of the string or the position of the
    119      *                  "{@code #}" character, if present. All information
    120      *                  after the sharp sign indicates an anchor.
    121      */
    122     protected void parseURL(URL u, String spec, int start, int limit) {
    123         // These fields may receive context content if this was relative URL
    124         String protocol = u.getProtocol();
    125         String authority = u.getAuthority();
    126         String userInfo = u.getUserInfo();
    127         String host = u.getHost();
    128         int port = u.getPort();
    129         String path = u.getPath();
    130         String query = u.getQuery();
    131 
    132         // This field has already been parsed
    133         String ref = u.getRef();
    134 
    135         boolean isRelPath = false;
    136         boolean queryOnly = false;
    137         // BEGIN Android-changed: App compat
    138         boolean querySet = false;
    139         // END Android-changed: App compat
    140 
    141 // FIX: should not assume query if opaque
    142         // Strip off the query part
    143         if (start < limit) {
    144             int queryStart = spec.indexOf('?');
    145             queryOnly = queryStart == start;
    146             if ((queryStart != -1) && (queryStart < limit)) {
    147                 query = spec.substring(queryStart+1, limit);
    148                 if (limit > queryStart)
    149                     limit = queryStart;
    150                 spec = spec.substring(0, queryStart);
    151                 // BEGIN Android-changed: App compat
    152                 querySet = true;
    153                 // END Android-changed: App compat
    154             }
    155         }
    156 
    157         int i = 0;
    158         // Parse the authority part if any
    159         // BEGIN Android-changed: App compat
    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         boolean isUNCName = false;
    166         // END Android-changed: App compat
    167         if (!isUNCName && (start <= limit - 2) && (spec.charAt(start) == '/') &&
    168             (spec.charAt(start + 1) == '/')) {
    169             start += 2;
    170             i = spec.indexOf('/', start);
    171             if (i < 0 || i > limit) {
    172                 i = spec.indexOf('?', start);
    173                 if (i < 0 || i > limit)
    174                     i = limit;
    175             }
    176 
    177             host = authority = spec.substring(start, i);
    178 
    179             int ind = authority.indexOf('@');
    180             if (ind != -1) {
    181                 if (ind != authority.lastIndexOf('@')) {
    182                     // more than one '@' in authority. This is not server based
    183                     userInfo = null;
    184                     host = null;
    185                 } else {
    186                     userInfo = authority.substring(0, ind);
    187                     host = authority.substring(ind+1);
    188                 }
    189             } else {
    190                 userInfo = null;
    191             }
    192             if (host != null) {
    193                 // If the host is surrounded by [ and ] then its an IPv6
    194                 // literal address as specified in RFC2732
    195                 if (host.length()>0 && (host.charAt(0) == '[')) {
    196                     if ((ind = host.indexOf(']')) > 2) {
    197 
    198                         String nhost = host ;
    199                         host = nhost.substring(0,ind+1);
    200                         if (!IPAddressUtil.
    201                             isIPv6LiteralAddress(host.substring(1, ind))) {
    202                             throw new IllegalArgumentException(
    203                                 "Invalid host: "+ host);
    204                         }
    205 
    206                         port = -1 ;
    207                         if (nhost.length() > ind+1) {
    208                             if (nhost.charAt(ind+1) == ':') {
    209                                 ++ind ;
    210                                 // port can be null according to RFC2396
    211                                 if (nhost.length() > (ind + 1)) {
    212                                     port = Integer.parseInt(nhost.substring(ind+1));
    213                                 }
    214                             } else {
    215                                 throw new IllegalArgumentException(
    216                                     "Invalid authority field: " + authority);
    217                             }
    218                         }
    219                     } else {
    220                         throw new IllegalArgumentException(
    221                             "Invalid authority field: " + authority);
    222                     }
    223                 } else {
    224                     ind = host.indexOf(':');
    225                     port = -1;
    226                     if (ind >= 0) {
    227                         // port can be null according to RFC2396
    228                         if (host.length() > (ind + 1)) {
    229                             // BEGIN Android-changed: App compat
    230                             // port = Integer.parseInt(host.substring(ind + 1));
    231                             char firstPortChar = host.charAt(ind+1);
    232                             if (firstPortChar >= '0' && firstPortChar <= '9') {
    233                                 port = Integer.parseInt(host.substring(ind + 1));
    234                             } else {
    235                                 throw new IllegalArgumentException("invalid port: " +
    236                                                                    host.substring(ind + 1));
    237                             }
    238                             // END Android-changed: App compat
    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 
    251             // If the authority is defined then the path is defined by the
    252             // spec only; See RFC 2396 Section 5.2.4.
    253             // BEGIN Android-changed: App compat
    254             // if (authority != null && authority.length() > 0)
    255             //   path = "";
    256             path = null;
    257             if (!querySet) {
    258                 query = null;
    259             }
    260             // END Android-changed: App compat
    261         }
    262 
    263         if (host == null) {
    264             host = "";
    265         }
    266 
    267         // Parse the file path if any
    268         if (start < limit) {
    269             if (spec.charAt(start) == '/') {
    270                 path = spec.substring(start, limit);
    271             } else if (path != null && path.length() > 0) {
    272                 isRelPath = true;
    273                 int ind = path.lastIndexOf('/');
    274                 String seperator = "";
    275                 if (ind == -1 && authority != null)
    276                     seperator = "/";
    277                 path = path.substring(0, ind + 1) + seperator +
    278                          spec.substring(start, limit);
    279 
    280             } else {
    281                 String seperator = (authority != null) ? "/" : "";
    282                 path = seperator + spec.substring(start, limit);
    283             }
    284         }
    285         // BEGIN Android-changed: App compat
    286         //else if (queryOnly && path != null) {
    287         //    int ind = path.lastIndexOf('/');
    288         //    if (ind < 0)
    289         //        ind = 0;
    290         //    path = path.substring(0, ind) + "/";
    291         //}
    292         // END Android-changed: App compat
    293         if (path == null)
    294             path = "";
    295 
    296         // BEGIN Android-changed
    297         //if (isRelPath) {
    298         if (true) {
    299         // END Android-changed
    300             // Remove embedded /./
    301             while ((i = path.indexOf("/./")) >= 0) {
    302                 path = path.substring(0, i) + path.substring(i + 2);
    303             }
    304             // Remove embedded /../ if possible
    305             i = 0;
    306             while ((i = path.indexOf("/../", i)) >= 0) {
    307                 // BEGIN Android-changed: App compat
    308                 /*
    309                  * Trailing /../
    310                  */
    311                 if (i == 0) {
    312                     path = path.substring(i + 3);
    313                     i = 0;
    314                 // END Android-changed: App compat
    315                 /*
    316                  * A "/../" will cancel the previous segment and itself,
    317                  * unless that segment is a "/../" itself
    318                  * i.e. "/a/b/../c" becomes "/a/c"
    319                  * but "/../../a" should stay unchanged
    320                  */
    321                 // Android-changed: App compat
    322                 // if (i > 0 && (limit = path.lastIndexOf('/', i - 1)) >= 0 &&
    323                 } else if (i > 0 && (limit = path.lastIndexOf('/', i - 1)) >= 0 &&
    324                     (path.indexOf("/../", limit) != 0)) {
    325                     path = path.substring(0, limit) + path.substring(i + 3);
    326                     i = 0;
    327                 } else {
    328                     i = i + 3;
    329                 }
    330             }
    331             // Remove trailing .. if possible
    332             while (path.endsWith("/..")) {
    333                 i = path.indexOf("/..");
    334                 if ((limit = path.lastIndexOf('/', i - 1)) >= 0) {
    335                     path = path.substring(0, limit+1);
    336                 } else {
    337                     break;
    338                 }
    339             }
    340             // Remove starting .
    341             if (path.startsWith("./") && path.length() > 2)
    342                 path = path.substring(2);
    343 
    344             // Remove trailing .
    345             if (path.endsWith("/."))
    346                 path = path.substring(0, path.length() -1);
    347 
    348             // Android-changed: App compat: Remove trailing ?
    349             if (path.endsWith("?"))
    350                 path = path.substring(0, path.length() -1);
    351         }
    352 
    353         setURL(u, protocol, host, port, authority, userInfo, path, query, ref);
    354     }
    355 
    356     /**
    357      * Returns the default port for a URL parsed by this handler. This method
    358      * is meant to be overidden by handlers with default port numbers.
    359      * @return the default port for a {@code URL} parsed by this handler.
    360      * @since 1.3
    361      */
    362     protected int getDefaultPort() {
    363         return -1;
    364     }
    365 
    366     /**
    367      * Provides the default equals calculation. May be overidden by handlers
    368      * for other protocols that have different requirements for equals().
    369      * This method requires that none of its arguments is null. This is
    370      * guaranteed by the fact that it is only called by java.net.URL class.
    371      * @param u1 a URL object
    372      * @param u2 a URL object
    373      * @return {@code true} if the two urls are
    374      * considered equal, ie. they refer to the same
    375      * fragment in the same file.
    376      * @since 1.3
    377      */
    378     protected boolean equals(URL u1, URL u2) {
    379         // Android-changed: Avoid network I/O
    380         return Objects.equals(u1.getRef(), u2.getRef()) &&
    381                Objects.equals(u1.getQuery(), u2.getQuery()) &&
    382                // sameFile compares the protocol, file, port & host components of
    383                // the URLs.
    384                sameFile(u1, u2);
    385     }
    386 
    387     /**
    388      * Provides the default hash calculation. May be overidden by handlers for
    389      * other protocols that have different requirements for hashCode
    390      * calculation.
    391      * @param u a URL object
    392      * @return an {@code int} suitable for hash table indexing
    393      * @since 1.3
    394      */
    395     protected int hashCode(URL u) {
    396         // Android-changed: Avoid network I/O
    397         // Hash on the same set of fields that we compare in equals().
    398         return Objects.hash(
    399                 u.getRef(),
    400                 u.getQuery(),
    401                 u.getProtocol(),
    402                 u.getFile(),
    403                 u.getHost(),
    404                 u.getPort());
    405     }
    406 
    407     /**
    408      * Compare two urls to see whether they refer to the same file,
    409      * i.e., having the same protocol, host, port, and path.
    410      * This method requires that none of its arguments is null. This is
    411      * guaranteed by the fact that it is only called indirectly
    412      * by java.net.URL class.
    413      * @param u1 a URL object
    414      * @param u2 a URL object
    415      * @return true if u1 and u2 refer to the same file
    416      * @since 1.3
    417      */
    418     protected boolean sameFile(URL u1, URL u2) {
    419         // Compare the protocols.
    420         if (!((u1.getProtocol() == u2.getProtocol()) ||
    421               (u1.getProtocol() != null &&
    422                u1.getProtocol().equalsIgnoreCase(u2.getProtocol()))))
    423             return false;
    424 
    425         // Compare the files.
    426         if (!(u1.getFile() == u2.getFile() ||
    427               (u1.getFile() != null && u1.getFile().equals(u2.getFile()))))
    428             return false;
    429 
    430         // Compare the ports.
    431         int port1, port2;
    432         port1 = (u1.getPort() != -1) ? u1.getPort() : u1.handler.getDefaultPort();
    433         port2 = (u2.getPort() != -1) ? u2.getPort() : u2.handler.getDefaultPort();
    434         if (port1 != port2)
    435             return false;
    436 
    437         // Compare the hosts.
    438         if (!hostsEqual(u1, u2))
    439             return false;
    440 
    441         return true;
    442     }
    443 
    444     /**
    445      * Get the IP address of our host. An empty host field or a DNS failure
    446      * will result in a null return.
    447      *
    448      * @param u a URL object
    449      * @return an {@code InetAddress} representing the host
    450      * IP address.
    451      * @since 1.3
    452      */
    453     protected synchronized InetAddress getHostAddress(URL u) {
    454         if (u.hostAddress != null)
    455             return u.hostAddress;
    456 
    457         String host = u.getHost();
    458         if (host == null || host.equals("")) {
    459             return null;
    460         } else {
    461             try {
    462                 u.hostAddress = InetAddress.getByName(host);
    463             } catch (UnknownHostException ex) {
    464                 return null;
    465             } catch (SecurityException se) {
    466                 return null;
    467             }
    468         }
    469         return u.hostAddress;
    470     }
    471 
    472     /**
    473      * Compares the host components of two URLs.
    474      * @param u1 the URL of the first host to compare
    475      * @param u2 the URL of the second host to compare
    476      * @return  {@code true} if and only if they
    477      * are equal, {@code false} otherwise.
    478      * @since 1.3
    479      */
    480     protected boolean hostsEqual(URL u1, URL u2) {
    481         // Android-changed: Don't compare the InetAddresses of the hosts.
    482         if (u1.getHost() != null && u2.getHost() != null)
    483             return u1.getHost().equalsIgnoreCase(u2.getHost());
    484          else
    485             return u1.getHost() == null && u2.getHost() == null;
    486     }
    487 
    488     /**
    489      * Converts a {@code URL} of a specific protocol to a
    490      * {@code String}.
    491      *
    492      * @param   u   the URL.
    493      * @return  a string representation of the {@code URL} argument.
    494      */
    495     protected String toExternalForm(URL u) {
    496 
    497         // pre-compute length of StringBuffer
    498         int len = u.getProtocol().length() + 1;
    499         if (u.getAuthority() != null && u.getAuthority().length() > 0)
    500             len += 2 + u.getAuthority().length();
    501         if (u.getPath() != null) {
    502             len += u.getPath().length();
    503         }
    504         if (u.getQuery() != null) {
    505             len += 1 + u.getQuery().length();
    506         }
    507         if (u.getRef() != null)
    508             len += 1 + u.getRef().length();
    509 
    510         // BEGIN Android-changed: Add a toExternalForm variant that optionally escapes illegal chars
    511         // TODO: The variant has been removed. We can potentially revert the change
    512         StringBuilder result = new StringBuilder(len);
    513         result.append(u.getProtocol());
    514         result.append(":");
    515         if (u.getAuthority() != null) {// ANDROID: && u.getAuthority().length() > 0) {
    516             result.append("//");
    517             result.append(u.getAuthority());
    518         }
    519         String fileAndQuery = u.getFile();
    520         if (fileAndQuery != null) {
    521             result.append(fileAndQuery);
    522         }
    523         // END Android-changed: Add a toExternalForm variant that optionally escapes illegal chars
    524         if (u.getRef() != null) {
    525             result.append("#");
    526             result.append(u.getRef());
    527         }
    528         return result.toString();
    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.
    538      * @param   host      the remote host value for the URL.
    539      * @param   port      the port on the remote machine.
    540      * @param   authority the authority part for the URL.
    541      * @param   userInfo the userInfo part of the URL.
    542      * @param   path      the path component of the URL.
    543      * @param   query     the query part for the URL.
    544      * @param   ref       the reference.
    545      * @exception       SecurityException       if the protocol handler of the URL is
    546      *                                  different from this one
    547      * @see     java.net.URL#set(java.lang.String, java.lang.String, int, java.lang.String, java.lang.String)
    548      * @since 1.3
    549      */
    550        protected void setURL(URL u, String protocol, String host, int port,
    551                              String authority, String userInfo, String path,
    552                              String query, String ref) {
    553         if (this != u.handler) {
    554             throw new SecurityException("handler for url different from " +
    555                                         "this handler");
    556         }
    557         // ensure that no one can reset the protocol on a given URL.
    558         u.set(u.getProtocol(), host, port, authority, userInfo, path, query, ref);
    559     }
    560 
    561     /**
    562      * Sets the fields of the {@code URL} argument to the indicated values.
    563      * Only classes derived from URLStreamHandler are able
    564      * to use this method to set the values of the URL fields.
    565      *
    566      * @param   u         the URL to modify.
    567      * @param   protocol  the protocol name. This value is ignored since 1.2.
    568      * @param   host      the remote host value for the URL.
    569      * @param   port      the port on the remote machine.
    570      * @param   file      the file.
    571      * @param   ref       the reference.
    572      * @exception       SecurityException       if the protocol handler of the URL is
    573      *                                  different from this one
    574      * @deprecated Use setURL(URL, String, String, int, String, String, String,
    575      *             String);
    576      */
    577     @Deprecated
    578     protected void setURL(URL u, String protocol, String host, int port,
    579                           String file, String ref) {
    580         /*
    581          * Only old URL handlers call this, so assume that the host
    582          * field might contain "user:passwd@host". Fix as necessary.
    583          */
    584         String authority = null;
    585         String userInfo = null;
    586         if (host != null && host.length() != 0) {
    587             authority = (port == -1) ? host : host + ":" + port;
    588             int at = host.lastIndexOf('@');
    589             if (at != -1) {
    590                 userInfo = host.substring(0, at);
    591                 host = host.substring(at+1);
    592             }
    593         }
    594 
    595         /*
    596          * Assume file might contain query part. Fix as necessary.
    597          */
    598         String path = null;
    599         String query = null;
    600         if (file != null) {
    601             int q = file.lastIndexOf('?');
    602             if (q != -1) {
    603                 query = file.substring(q+1);
    604                 path = file.substring(0, q);
    605             } else
    606                 path = file;
    607         }
    608         setURL(u, protocol, host, port, authority, userInfo, path, query, ref);
    609     }
    610 }
    611