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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  
18  package org.apache.commons.net.ftp.parser;
19  
20  import java.util.HashMap;
21  import java.util.List;
22  import java.util.ListIterator;
23  import java.util.regex.MatchResult;
24  import java.util.regex.Matcher;
25  import java.util.regex.Pattern;
26  import java.util.regex.PatternSyntaxException;
27  
28  import org.apache.commons.net.ftp.FTPClientConfig;
29  
30  /**
31   * Special implementation VMSFTPEntryParser with versioning turned on.
32   * This parser removes all duplicates and only leaves the version with the highest
33   * version number for each filename.
34   *
35   * This is a sample of VMS LIST output
36   *
37   *  "1-JUN.LIS;1              9/9           2-JUN-1998 07:32:04  [GROUP,OWNER]    (RWED,RWED,RWED,RE)",
38   *  "1-JUN.LIS;2              9/9           2-JUN-1998 07:32:04  [GROUP,OWNER]    (RWED,RWED,RWED,RE)",
39   *  "DATA.DIR;1               1/9           2-JUN-1998 07:32:04  [GROUP,OWNER]    (RWED,RWED,RWED,RE)",
40   * <P>
41   *
42   * @author  <a href="Winston.Ojeda@qg.com">Winston Ojeda</a>
43   * @author <a href="sestegra@free.fr">Stephane ESTE-GRACIAS</a>
44   * @version $Id: VMSVersioningFTPEntryParser.java 1299238 2012-03-10 17:12:28Z sebb $
45   *
46   * @see org.apache.commons.net.ftp.FTPFileEntryParser FTPFileEntryParser (for usage instructions)
47   */
48  public class VMSVersioningFTPEntryParser extends VMSFTPEntryParser
49  {
50  
51      private final Pattern _preparse_pattern_;
52      private static final String PRE_PARSE_REGEX =
53          "(.*);([0-9]+)\\s*.*";
54  
55      /**
56       * Constructor for a VMSFTPEntryParser object.
57       *
58       * @exception IllegalArgumentException
59       * Thrown if the regular expression is unparseable.  Should not be seen
60       * under normal conditions.  It it is seen, this is a sign that
61       * <code>REGEX</code> is  not a valid regular expression.
62       */
63      public VMSVersioningFTPEntryParser()
64      {
65          this(null);
66      }
67  
68      /**
69       * This constructor allows the creation of a VMSVersioningFTPEntryParser
70       * object with something other than the default configuration.
71       *
72       * @param config The {@link FTPClientConfig configuration} object used to
73       * configure this parser.
74       * @exception IllegalArgumentException
75       * Thrown if the regular expression is unparseable.  Should not be seen
76       * under normal conditions.  It it is seen, this is a sign that
77       * <code>REGEX</code> is  not a valid regular expression.
78       * @since 1.4
79       */
80      public VMSVersioningFTPEntryParser(FTPClientConfig config)
81      {
82          super();
83          configure(config);
84          try
85          {
86              //_preparse_matcher_ = new Perl5Matcher();
87              _preparse_pattern_ = Pattern.compile(PRE_PARSE_REGEX);
88          }
89          catch (PatternSyntaxException pse)
90          {
91              throw new IllegalArgumentException (
92                  "Unparseable regex supplied:  " + PRE_PARSE_REGEX);
93          }
94  
95     }
96  
97      /**
98       * Implement hook provided for those implementers (such as
99       * VMSVersioningFTPEntryParser, and possibly others) which return
100      * multiple files with the same name to remove the duplicates ..
101      *
102      * @param original Original list
103      *
104      * @return Original list purged of duplicates
105      */
106     @Override
107     public List<String> preParse(List<String> original) {
108         HashMap<String, Integer> existingEntries = new HashMap<String, Integer>();
109         ListIterator<String> iter = original.listIterator();
110         while (iter.hasNext()) {
111             String entry = iter.next().trim();
112             MatchResult result = null;
113             Matcher _preparse_matcher_ = _preparse_pattern_.matcher(entry);
114             if (_preparse_matcher_.matches()) {
115                 result = _preparse_matcher_.toMatchResult();
116                 String name = result.group(1);
117                 String version = result.group(2);
118                 Integer nv = Integer.valueOf(version);
119                 Integer existing = existingEntries.get(name);
120                 if (null != existing) {
121                     if (nv.intValue() < existing.intValue()) {
122                         iter.remove();  // removes older version from original list.
123                         continue;
124                     }
125                 }
126                 existingEntries.put(name, nv);
127             }
128 
129         }
130         // we've now removed all entries less than with less than the largest
131         // version number for each name that were listed after the largest.
132         // we now must remove those with smaller than the largest version number
133         // for each name that were found before the largest
134         while (iter.hasPrevious()) {
135             String entry = iter.previous().trim();
136             MatchResult result = null;
137             Matcher _preparse_matcher_ = _preparse_pattern_.matcher(entry);
138             if (_preparse_matcher_.matches()) {
139                 result = _preparse_matcher_.toMatchResult();
140                 String name = result.group(1);
141                 String version = result.group(2);
142                 Integer nv = Integer.valueOf(version);
143                 Integer existing = existingEntries.get(name);
144                 if (null != existing) {
145                     if (nv.intValue() < existing.intValue()) {
146                         iter.remove(); // removes older version from original list.
147                     }
148                 }
149             }
150 
151         }
152         return original;
153     }
154 
155 
156     @Override
157     protected boolean isVersioning() {
158         return true;
159     }
160 
161 }
162 
163 /* Emacs configuration
164  * Local variables:        **
165  * mode:             java  **
166  * c-basic-offset:   4     **
167  * indent-tabs-mode: nil   **
168  * End:                    **
169  */