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      1 /*
      2  * Copyright (c) 1994, 2003, 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 sun.net.www.protocol.file;
     27 
     28 import java.net.InetAddress;
     29 import java.net.URLConnection;
     30 import java.net.URL;
     31 import java.net.Proxy;
     32 import java.net.MalformedURLException;
     33 import java.net.URLStreamHandler;
     34 import java.io.InputStream;
     35 import java.io.IOException;
     36 import sun.net.www.ParseUtil;
     37 import java.io.File;
     38 
     39 /**
     40  * Open an file input stream given a URL.
     41  * @author      James Gosling
     42  */
     43 public class Handler extends URLStreamHandler {
     44 
     45     private String getHost(URL url) {
     46         String host = url.getHost();
     47         if (host == null)
     48             host = "";
     49         return host;
     50     }
     51 
     52 
     53     protected void parseURL(URL u, String spec, int start, int limit) {
     54         /*
     55          * Ugly backwards compatibility. Flip any file separator
     56          * characters to be forward slashes. This is a nop on Unix
     57          * and "fixes" win32 file paths. According to RFC 2396,
     58          * only forward slashes may be used to represent hierarchy
     59          * separation in a URL but previous releases unfortunately
     60          * performed this "fixup" behavior in the file URL parsing code
     61          * rather than forcing this to be fixed in the caller of the URL
     62          * class where it belongs. Since backslash is an "unwise"
     63          * character that would normally be encoded if literally intended
     64          * as a non-seperator character the damage of veering away from the
     65          * specification is presumably limited.
     66          */
     67         super.parseURL(u, spec.replace(File.separatorChar, '/'), start, limit);
     68     }
     69 
     70     public synchronized URLConnection openConnection(URL u)
     71         throws IOException {
     72         return openConnection(u, null);
     73     }
     74 
     75     public synchronized URLConnection openConnection(URL u, Proxy p)
     76            throws IOException {
     77         String host = u.getHost();
     78         if (host == null || host.equals("") || host.equals("~") ||
     79             host.equalsIgnoreCase("localhost")) {
     80             File file = new File(ParseUtil.decode(u.getPath()));
     81             return createFileURLConnection(u, file);
     82         }
     83 
     84         /* If you reach here, it implies that you have a hostname
     85            so attempt an ftp connection.
     86          */
     87         URLConnection uc;
     88         URL ru;
     89 
     90         try {
     91             ru = new URL("ftp", host, u.getFile() +
     92                              (u.getRef() == null ? "": "#" + u.getRef()));
     93             if (p != null) {
     94                 uc = ru.openConnection(p);
     95             } else {
     96                 uc = ru.openConnection();
     97             }
     98         } catch (IOException e) {
     99             uc = null;
    100         }
    101         if (uc == null) {
    102             throw new IOException("Unable to connect to: " +
    103                                                        u.toExternalForm());
    104         }
    105         return uc;
    106     }
    107 
    108     // Template method to be overriden by Java Plug-in. [stanleyh]
    109     //
    110     protected URLConnection createFileURLConnection(URL u, File file)
    111     {
    112         return new FileURLConnection(u, file);
    113     }
    114 
    115     /**
    116      * Compares the host components of two URLs.
    117      * @param u1 the URL of the first host to compare
    118      * @param u2 the URL of the second host to compare
    119      * @return  <tt>true</tt> if and only if they
    120      * are equal, <tt>false</tt> otherwise.
    121      */
    122     protected boolean hostsEqual(URL u1, URL u2) {
    123         /*
    124          * Special case for file: URLs
    125          * per RFC 1738 no hostname is equivalent to 'localhost'
    126          * i.e. file:///path is equal to file://localhost/path
    127          */
    128         String s1 = u1.getHost();
    129         String s2 = u2.getHost();
    130         if ("localhost".equalsIgnoreCase(s1) && ( s2 == null || "".equals(s2)))
    131             return true;
    132         if ("localhost".equalsIgnoreCase(s2) && ( s1 == null || "".equals(s1)))
    133             return true;
    134         return super.hostsEqual(u1, u2);
    135     }
    136 }
    137