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. This parser removes all duplicates and only leaves the version with the highest version
32 * number for each file name.
33 * <p>
34 * This is a sample of VMS LIST output
35 * </p>
36 *
37 * <pre>
38 * "1-JUN.LIS;1 9/9 2-JUN-1998 07:32:04 [GROUP,OWNER] (RWED,RWED,RWED,RE)",
39 * "1-JUN.LIS;2 9/9 2-JUN-1998 07:32:04 [GROUP,OWNER] (RWED,RWED,RWED,RE)",
40 * "DATA.DIR;1 1/9 2-JUN-1998 07:32:04 [GROUP,OWNER] (RWED,RWED,RWED,RE)",
41 * </pre>
42 *
43 * @see org.apache.commons.net.ftp.FTPFileEntryParser FTPFileEntryParser (for usage instructions)
44 */
45 public class VMSVersioningFTPEntryParser extends VMSFTPEntryParser {
46
47 private static final String PRE_PARSE_REGEX = "(.*?);([0-9]+)\\s*.*";
48 private final Pattern preparsePattern;
49
50 /**
51 * Constructor for a VMSFTPEntryParser object.
52 *
53 * @throws IllegalArgumentException Thrown if the regular expression is unparseable. Should not be seen under normal conditions. If the exception is seen,
54 * this is a sign that <code>REGEX</code> is not a valid regular expression.
55 */
56 public VMSVersioningFTPEntryParser() {
57 this(null);
58 }
59
60 /**
61 * This constructor allows the creation of a VMSVersioningFTPEntryParser object with something other than the default configuration.
62 *
63 * @param config The {@link FTPClientConfig configuration} object used to configure this parser.
64 * @throws IllegalArgumentException Thrown if the regular expression is unparseable. Should not be seen under normal conditions. If the exception is seen,
65 * this is a sign that <code>REGEX</code> is not a valid regular expression.
66 * @since 1.4
67 */
68 public VMSVersioningFTPEntryParser(final FTPClientConfig config) {
69 configure(config);
70 try {
71 // _preparse_matcher_ = new Perl5Matcher();
72 preparsePattern = Pattern.compile(PRE_PARSE_REGEX);
73 } catch (final PatternSyntaxException pse) {
74 throw new IllegalArgumentException("Unparseable regex supplied: " + PRE_PARSE_REGEX);
75 }
76
77 }
78
79 @Override
80 protected boolean isVersioning() {
81 return true;
82 }
83
84 /**
85 * Implement hook provided for those implementers (such as VMSVersioningFTPEntryParser, and possibly others) which return multiple files with the same name
86 * to remove the duplicates ..
87 *
88 * @param original Original list
89 *
90 * @return Original list purged of duplicates
91 */
92 @Override
93 public List<String> preParse(final List<String> original) {
94 final HashMap<String, Integer> existingEntries = new HashMap<>();
95 final ListIterator<String> iter = original.listIterator();
96 while (iter.hasNext()) {
97 final String entry = iter.next().trim();
98 MatchResult result;
99 final Matcher _preparse_matcher_ = preparsePattern.matcher(entry);
100 if (_preparse_matcher_.matches()) {
101 result = _preparse_matcher_.toMatchResult();
102 final String name = result.group(1);
103 final String version = result.group(2);
104 final Integer nv = Integer.valueOf(version);
105 final Integer existing = existingEntries.get(name);
106 if (null != existing && nv.intValue() < existing.intValue()) {
107 iter.remove(); // removes older version from original list.
108 continue;
109 }
110 existingEntries.put(name, nv);
111 }
112
113 }
114 // we've now removed all entries less than with less than the largest
115 // version number for each name that were listed after the largest.
116 // we now must remove those with smaller than the largest version number
117 // for each name that were found before the largest
118 while (iter.hasPrevious()) {
119 final String entry = iter.previous().trim();
120 MatchResult result = null;
121 final Matcher _preparse_matcher_ = preparsePattern.matcher(entry);
122 if (_preparse_matcher_.matches()) {
123 result = _preparse_matcher_.toMatchResult();
124 final String name = result.group(1);
125 final String version = result.group(2);
126 final int nv = Integer.parseInt(version);
127 final Integer existing = existingEntries.get(name);
128 if (null != existing && nv < existing.intValue()) {
129 iter.remove(); // removes older version from original list.
130 }
131 }
132
133 }
134 return original;
135 }
136
137 }