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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;
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   * Implementation for layered filesystems.
25   * <p/>
26   * Additionally encodes the '!' character.
27   */
28  public class LayeredFileNameParser extends AbstractFileNameParser
29  {
30      private final static LayeredFileNameParser INSTANCE = new LayeredFileNameParser();
31  
32      public static LayeredFileNameParser getInstance()
33      {
34          return INSTANCE;
35      }
36  
37      public boolean encodeCharacter(char ch)
38      {
39          return super.encodeCharacter(ch) || ch == '!';
40      }
41  
42      public FileName parseUri(final VfsComponentContext context, FileName base, final String filename) throws FileSystemException
43      {
44          final StringBuffer name = new StringBuffer();
45  
46          // Extract the scheme
47          final String scheme = UriParser.extractScheme(filename, name);
48  
49          // Extract the Layered file URI
50          final String rootUriName = extractRootName(name);
51          FileName rootUri = null;
52          if (rootUriName != null)
53          {
54              rootUri = context.parseURI(rootUriName);
55          }
56  
57          // Decode and normalise the path
58          UriParser.canonicalizePath(name, 0, name.length(), this);
59          UriParser.fixSeparators(name);
60          FileType fileType = UriParser.normalisePath(name);
61          final String path = name.toString();
62  
63          return new LayeredFileName(scheme, rootUri, path, fileType);
64      }
65  
66      /***
67       * Pops the root prefix off a URI, which has had the scheme removed.
68       */
69      protected String extractRootName(final StringBuffer uri)
70          throws FileSystemException
71      {
72          // Looking for <name>!<abspath> (staring at the end)
73          int maxlen = uri.length();
74          int pos = maxlen - 1;
75          for (; pos > 0 && uri.charAt(pos) != '!'; pos--)
76          {
77          }
78  
79          if (pos == 0 && uri.charAt(pos) != '!')
80          {
81              // not ! found, so take the whole path a root
82              // e.g. zip:/my/zip/file.zip
83              pos = maxlen;
84          }
85  
86          // Extract the name
87          String prefix = uri.substring(0, pos);
88          if (pos < maxlen)
89          {
90              uri.delete(0, pos + 1);
91          }
92          else
93          {
94              uri.setLength(0);
95          }
96  
97          return prefix;
98      }
99  
100 }