jurt/com/sun/star/lib/util/UrlToFileMapper.java

   1 /*
   2  * This file is part of the LibreOffice project.
   3  *
   4  * This Source Code Form is subject to the terms of the Mozilla Public
   5  * License, v. 2.0. If a copy of the MPL was not distributed with this
   6  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   7  *
   8  * This file incorporates work covered by the following license notice:
   9  *
  10  *   Licensed to the Apache Software Foundation (ASF) under one or more
  11  *   contributor license agreements. See the NOTICE file distributed
  12  *   with this work for additional information regarding copyright
  13  *   ownership. The ASF licenses this file to you under the Apache
  14  *   License, Version 2.0 (the "License"); you may not use this file
  15  *   except in compliance with the License. You may obtain a copy of
  16  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  17  */
  18 package com.sun.star.lib.util;
  19
  20 import java.io.File;
  21 import java.io.UnsupportedEncodingException;
  22 import java.net.URI;
  23 import java.net.URISyntaxException;
  24 import java.net.URL;
  25 import java.net.URLEncoder;
  26
  27 /**
  28  * Maps Java URL representations to File representations, on any Java version.
  29  *
  30  * This used to be used to do URL to File mapping in pre-Java1.4 days, but since
  31  * we now require Java 1.5, it is largely unnecessary.
  32  *
  33  * @since UDK 3.2.8
  34  */
  35 public final class UrlToFileMapper {
  36
  37     /**
  38      * Maps Java URL representations to File representations.
  39      *
  40      * @param url some URL, possibly null.
  41      * @return a corresponding File, or null on failure.
  42      */
  43     public static File mapUrlToFile(URL url) {
  44         if (url == null) {
  45             return null;
  46         } else {
  47             try {
  48                 // where encodedUrl is url.toString(), but since that may contain
  49                 // unsafe characters (e.g., space, " "), it is encoded, as otherwise
  50                 // the URI constructor might throw java.net.URISyntaxException (in
  51                 // Java 1.5, URL.toURI might be used instead).
  52                 String encodedUrl = encode(url.toString());
  53                 URI uri = new URI(encodedUrl);
  54                 try {
  55                     return new File(uri);
  56                 } catch (IllegalArgumentException e) {
  57                     return null;
  58                 }
  59             } catch (URISyntaxException ex) {
  60                 throw new RuntimeException(ex); // should never happen
  61             }
  62         }
  63     }
  64
  65     private static String encode(String url) {
  66         StringBuffer buf = new StringBuffer(url.length());
  67         for (int i = 0; i < url.length(); ++i) {
  68             char c = url.charAt(i);
  69             // The RFC 2732 <uric> characters: !$&'()*+,-./:;=?@[]_~ plus digits
  70             // and letters; additionally, do not encode % again.
  71             if (c >= 'a' && c <= 'z' || c >= '?' && c <= '['
  72                 || c >= '$' && c <= ';' || c == '!' || c == '=' || c == ']'
  73                 || c == '_' || c == '~')
  74             {
  75                 buf.append(c);
  76             } else if (c == ' ') {
  77                 buf.append("%20");
  78             } else {
  79                 try {
  80                     String enc = URLEncoder.encode(Character.toString(c), "UTF-8");
  81                     buf.append(enc);
  82                 } catch (UnsupportedEncodingException e) {
  83                     throw new RuntimeException(e); // should never happen
  84                 }
  85             }
  86         }
  87         return buf.toString();
  88     }
  89
  90     private UrlToFileMapper() {}
  91 }