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 636854 2008-03-13 19:55:01Z 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 Matcher _preparse_matcher_;
52 private Pattern _preparse_pattern_;
53 private static final String PRE_PARSE_REGEX =
54 "(.*);([0-9]+)\\s*.*";
55
56 /**
57 * Constructor for a VMSFTPEntryParser object. Sets the versioning member
58 * to the supplied value.
59 *
60 * @exception IllegalArgumentException
61 * Thrown if the regular expression is unparseable. Should not be seen
62 * under normal conditions. It it is seen, this is a sign that
63 * <code>REGEX</code> is not a valid regular expression.
64 */
65 public VMSVersioningFTPEntryParser()
66 {
67 this(null);
68 }
69
70 /**
71 * This constructor allows the creation of a VMSVersioningFTPEntryParser
72 * object with something other than the default configuration.
73 *
74 * @param config The {@link FTPClientConfig configuration} object used to
75 * configure this parser.
76 * @exception IllegalArgumentException
77 * Thrown if the regular expression is unparseable. Should not be seen
78 * under normal conditions. It it is seen, this is a sign that
79 * <code>REGEX</code> is not a valid regular expression.
80 * @since 1.4
81 */
82 public VMSVersioningFTPEntryParser(FTPClientConfig config)
83 {
84 super();
85 configure(config);
86 try
87 {
88 //_preparse_matcher_ = new Perl5Matcher();
89 _preparse_pattern_ = Pattern.compile(PRE_PARSE_REGEX);
90 }
91 catch (PatternSyntaxException pse)
92 {
93 throw new IllegalArgumentException (
94 "Unparseable regex supplied: " + PRE_PARSE_REGEX);
95 }
96
97 }
98
99
100
101 private static class NameVersion {
102 String name;
103 int versionNumber;
104 NameVersion(String name, String vers) {
105 this.name = name;
106 this.versionNumber = Integer.parseInt(vers);
107 }
108 }
109
110 /**
111 * Implement hook provided for those implementers (such as
112 * VMSVersioningFTPEntryParser, and possibly others) which return
113 * multiple files with the same name to remove the duplicates ..
114 *
115 * @param original Original list
116 *
117 * @return Original list purged of duplicates
118 */
119 @Override
120 public List<String> preParse(List<String> original) {
121 original = super.preParse(original);
122 HashMap<String, NameVersion> existingEntries = new HashMap<String, NameVersion>();
123 ListIterator<String> iter = original.listIterator();
124 while (iter.hasNext()) {
125 String entry = iter.next().trim();
126 MatchResult result = null;
127 _preparse_matcher_ = _preparse_pattern_.matcher(entry);
128 if (_preparse_matcher_.matches()) {
129 result = _preparse_matcher_.toMatchResult();
130 String name = result.group(1);
131 String version = result.group(2);
132 NameVersion nv = new NameVersion(name, version);
133 NameVersion existing = existingEntries.get(name);
134 if (null != existing) {
135 if (nv.versionNumber < existing.versionNumber) {
136 iter.remove(); // removal removes from original list.
137 continue;
138 }
139 }
140 existingEntries.put(name, nv);
141 }
142
143 }
144 // we've now removed all entries less than with less than the largest
145 // version number for each name that were listed after the largest.
146 // we now must remove those with smaller than the largest version number
147 // for each name that were found before the largest
148 while (iter.hasPrevious()) {
149 String entry = iter.previous().trim();
150 MatchResult result = null;
151 _preparse_matcher_ = _preparse_pattern_.matcher(entry);
152 if (_preparse_matcher_.matches()) {
153 result = _preparse_matcher_.toMatchResult();
154 String name = result.group(1);
155 String version = result.group(2);
156 NameVersion nv = new NameVersion(name, version);
157 NameVersion existing = existingEntries.get(name);
158 if (null != existing) {
159 if (nv.versionNumber < existing.versionNumber) {
160 iter.remove(); // removal removes from original list.
161 }
162 }
163 }
164
165 }
166 return original;
167 }
168
169
170 @Override
171 protected boolean isVersioning() {
172 return true;
173 }
174
175 }
176
177 /* Emacs configuration
178 * Local variables: **
179 * mode: java **
180 * c-basic-offset: 4 **
181 * indent-tabs-mode: nil **
182 * End: **
183 */