1 /************************************************************** 2 * 3 * Licensed to the Apache Software Foundation (ASF) under one 4 * or more contributor license agreements. See the NOTICE file 5 * distributed with this work for additional information 6 * regarding copyright ownership. The ASF licenses this file 7 * to you under the Apache License, Version 2.0 (the 8 * "License"); you may not use this file except in compliance 9 * with the License. You may obtain a copy of the License at 10 * 11 * http://www.apache.org/licenses/LICENSE-2.0 12 * 13 * Unless required by applicable law or agreed to in writing, 14 * software distributed under the License is distributed on an 15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16 * KIND, either express or implied. See the License for the 17 * specific language governing permissions and limitations 18 * under the License. 19 * 20 *************************************************************/ 21 22 23 package com.sun.star.lib.util; 24 25 import java.io.File; 26 import java.lang.reflect.Constructor; 27 import java.lang.reflect.InvocationTargetException; 28 import java.lang.reflect.Method; 29 import java.net.URL; 30 import java.net.URLDecoder; 31 import java.net.URLEncoder; 32 33 /** 34 * Maps Java URL representations to File representations, on any Java version. 35 * 36 * @since UDK 3.2.8 37 */ 38 public final class UrlToFileMapper { 39 40 // java.net.URLEncoder.encode(String, String) and java.net.URI are only 41 // available since Java 1.4: 42 private static Method urlEncoderEncode; 43 private static Constructor uriConstructor; 44 private static Constructor fileConstructor; 45 static { 46 try { 47 urlEncoderEncode = URLEncoder.class.getMethod( 48 "encode", new Class[] { String.class, String.class }); 49 Class uriClass = Class.forName("java.net.URI"); 50 uriConstructor = uriClass.getConstructor( 51 new Class[] { String.class }); 52 fileConstructor = File.class.getConstructor( 53 new Class[] { uriClass }); 54 } catch (ClassNotFoundException e) { 55 } catch (NoSuchMethodException e) { 56 } 57 } 58 59 /** 60 * Maps Java URL representations to File representations. 61 * 62 * @param url some URL, possibly null. 63 * @return a corresponding File, or null on failure. 64 */ mapUrlToFile(URL url)65 public static File mapUrlToFile(URL url) { 66 if (url == null) { 67 return null; 68 } else if (fileConstructor == null) { 69 // If java.net.URI is not available, hope that the following works 70 // well: First, check that the given URL has a certain form. 71 // Second, use the URLDecoder to decode the URL path (taking care 72 // not to change any plus signs to spaces), hoping that the used 73 // default encoding is the proper one for file URLs. Third, create 74 // a File from the decoded path. 75 return url.getProtocol().equalsIgnoreCase("file") 76 && url.getAuthority() == null && url.getQuery() == null 77 && url.getRef() == null 78 ? new File(URLDecoder.decode( 79 StringHelper.replace(url.getPath(), '+', "%2B"))) 80 : null; 81 } else { 82 // If java.net.URI is avaliable, do 83 // URI uri = new URI(encodedUrl); 84 // try { 85 // return new File(uri); 86 // } catch (IllegalArgumentException e) { 87 // return null; 88 // } 89 // where encodedUrl is url.toString(), but since that may contain 90 // unsafe characters (e.g., space, " "), it is encoded, as otherwise 91 // the URI constructor might throw java.net.URISyntaxException (in 92 // Java 1.5, URL.toURI might be used instead). 93 String encodedUrl = encode(url.toString()); 94 try { 95 Object uri = uriConstructor.newInstance( 96 new Object[] { encodedUrl }); 97 try { 98 return (File) fileConstructor.newInstance( 99 new Object[] { uri }); 100 } catch (InvocationTargetException e) { 101 if (e.getTargetException() instanceof 102 IllegalArgumentException) { 103 return null; 104 } else { 105 throw e; 106 } 107 } 108 } catch (InstantiationException e) { 109 throw new RuntimeException("This cannot happen: " + e); 110 } catch (IllegalAccessException e) { 111 throw new RuntimeException("This cannot happen: " + e); 112 } catch (InvocationTargetException e) { 113 if (e.getTargetException() instanceof Error) { 114 throw (Error) e.getTargetException(); 115 } else if (e.getTargetException() instanceof RuntimeException) { 116 throw (RuntimeException) e.getTargetException(); 117 } else { 118 throw new RuntimeException("This cannot happen: " + e); 119 } 120 } 121 } 122 } 123 124 125 encode(String url)126 private static String encode(String url) { 127 StringBuffer buf = new StringBuffer(); 128 for (int i = 0; i < url.length(); ++i) { 129 char c = url.charAt(i); 130 // The RFC 2732 <uric> characters: !$&'()*+,-./:;=?@[]_~ plus digits 131 // and letters; additionally, do not encode % again. 132 if (c >= 'a' && c <= 'z' || c >= '?' && c <= '[' 133 || c >= '$' && c <= ';' || c == '!' || c == '=' || c == ']' 134 || c == '_' || c == '~') 135 { 136 buf.append(c); 137 } else if (c == ' ') { 138 buf.append("%20"); 139 } else { 140 String enc; 141 try { 142 enc = (String) urlEncoderEncode.invoke( 143 null, 144 new Object[] {Character.toString(c), "UTF-8" }); 145 } catch (IllegalAccessException e) { 146 throw new RuntimeException("This cannot happen: " + e); 147 } catch (InvocationTargetException e) { 148 throw new RuntimeException("This cannot happen: " + e); 149 } 150 buf.append(enc); 151 } 152 } 153 return buf.toString(); 154 } 155 UrlToFileMapper()156 private UrlToFileMapper() {} 157 } 158