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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    * 
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   * 
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.vfs.provider.local;
18  
19  import org.apache.commons.vfs.FileName;
20  import org.apache.commons.vfs.FileSystemException;
21  import org.apache.commons.vfs.FileType;
22  
23  /***
24   * A parser for Windows file names.
25   *
26   * @author <a href="mailto:adammurdoch@apache.org">Adam Murdoch</a>
27   * @version $Revision: 480428 $ $Date: 2006-11-29 07:15:24 +0100 (Mi, 29 Nov 2006) $
28   */
29  public class WindowsFileNameParser
30      extends LocalFileNameParser
31  {
32      /***
33       * Pops the root prefix off a URI, which has had the scheme removed.
34       */
35      protected String extractRootPrefix(final String uri,
36                                         final StringBuffer name)
37          throws FileSystemException
38      {
39          return extractWindowsRootPrefix(uri, name);
40      }
41  
42      protected FileName createFileName(String scheme, final String rootFile, final String path, final FileType type)
43      {
44          return new WindowsFileName(scheme, rootFile, path, type);
45      }
46  
47      /***
48       * Extracts a Windows root prefix from a name.
49       */
50      private String extractWindowsRootPrefix(final String uri,
51                                              final StringBuffer name)
52          throws FileSystemException
53      {
54          // Looking for:
55          // ('/'){0, 3} <letter> ':' '/'
56          // ['/'] '//' <name> '/' <name> ( '/' | <end> )
57  
58          // Skip over first 4 (unc) leading '/' chars
59          int startPos = 0;
60          int maxlen = Math.min(4, name.length());
61          for (; startPos < maxlen && name.charAt(startPos) == '/'; startPos++)
62          {
63          }
64          if (startPos == maxlen && name.length() > startPos && name.charAt(startPos + 1) == '/')
65          {
66              // Too many '/'
67              throw new FileSystemException("vfs.provider.local/not-absolute-file-name.error", uri);
68          }
69          name.delete(0, startPos);
70  
71          // Look for drive name
72          String driveName = extractDrivePrefix(name);
73          if (driveName != null)
74          {
75              return driveName;
76          }
77  
78          // Look for UNC name
79          if (startPos < 2)
80          {
81              throw new FileSystemException("vfs.provider.local/not-absolute-file-name.error", uri);
82          }
83  
84          return "//" + extractUNCPrefix(uri, name);
85      }
86  
87      /***
88       * Extracts a drive prefix from a path.  Leading '/' chars have been removed.
89       */
90      private String extractDrivePrefix(final StringBuffer name)
91      {
92          // Looking for <letter> ':' '/'
93          if (name.length() < 3)
94          {
95              // Too short
96              return null;
97          }
98          char ch = name.charAt(0);
99          if (ch == '/' || ch == ':')
100         {
101             // Missing drive letter
102             return null;
103         }
104         if (name.charAt(1) != ':')
105         {
106             // Missing ':'
107             return null;
108         }
109         if (name.charAt(2) != '/')
110         {
111             // Missing separator
112             return null;
113         }
114 
115         String prefix = name.substring(0, 2);
116         name.delete(0, 2);
117         
118         return prefix.intern();
119     }
120 
121     /***
122      * Extracts a UNC name from a path.  Leading '/' chars have been removed.
123      */
124     private String extractUNCPrefix(final String uri,
125                                     final StringBuffer name)
126         throws FileSystemException
127     {
128         // Looking for <name> '/' <name> ( '/' | <end> )
129 
130         // Look for first separator
131         int maxpos = name.length();
132         int pos = 0;
133         for (; pos < maxpos && name.charAt(pos) != '/'; pos++)
134         {
135         }
136         pos++;
137         if (pos >= maxpos)
138         {
139             throw new FileSystemException("vfs.provider.local/missing-share-name.error", uri);
140         }
141 
142         // Now have <name> '/'
143         int startShareName = pos;
144         for (; pos < maxpos && name.charAt(pos) != '/'; pos++)
145         {
146         }
147         if (pos == startShareName)
148         {
149             throw new FileSystemException("vfs.provider.local/missing-share-name.error", uri);
150         }
151 
152         // Now have <name> '/' <name> ( '/' | <end> )
153         String prefix = name.substring(0, pos);
154         name.delete(0, pos);
155         return prefix;
156     }
157 }