    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017
    018package org.apache.commons.net.ftp.parser;
    019
    020import java.util.HashMap;
    021import java.util.List;
    022import java.util.ListIterator;
    023import java.util.regex.MatchResult;
    024import java.util.regex.Matcher;
    025import java.util.regex.Pattern;
    026import java.util.regex.PatternSyntaxException;
    027
    028import org.apache.commons.net.ftp.FTPClientConfig;
    029
    030/**
    031 * Special implementation VMSFTPEntryParser with versioning turned on.
    032 * This parser removes all duplicates and only leaves the version with the highest
    033 * version number for each filename.
    034 *
    035 * This is a sample of VMS LIST output
    036 *
    037 *  "1-JUN.LIS;1              9/9           2-JUN-1998 07:32:04  [GROUP,OWNER]    (RWED,RWED,RWED,RE)",
    038 *  "1-JUN.LIS;2              9/9           2-JUN-1998 07:32:04  [GROUP,OWNER]    (RWED,RWED,RWED,RE)",
    039 *  "DATA.DIR;1               1/9           2-JUN-1998 07:32:04  [GROUP,OWNER]    (RWED,RWED,RWED,RE)",
    040 * <P>
    041 *
    042 * @author  <a href="Winston.Ojeda@qg.com">Winston Ojeda</a>
    043 * @author <a href="sestegra@free.fr">Stephane ESTE-GRACIAS</a>
    044 * @version $Id: VMSVersioningFTPEntryParser.java 1299238 2012-03-10 17:12:28Z sebb $
    045 *
    046 * @see org.apache.commons.net.ftp.FTPFileEntryParser FTPFileEntryParser (for usage instructions)
    047 */
    048public class VMSVersioningFTPEntryParser extends VMSFTPEntryParser
    049{
    050
    051    private final Pattern _preparse_pattern_;
    052    private static final String PRE_PARSE_REGEX =
    053        "(.*);([0-9]+)\\s*.*";
    054
    055    /**
    056     * Constructor for a VMSFTPEntryParser object.
    057     *
    058     * @exception IllegalArgumentException
    059     * Thrown if the regular expression is unparseable.  Should not be seen
    060     * under normal conditions.  It it is seen, this is a sign that
    061     * <code>REGEX</code> is  not a valid regular expression.
    062     */
    063    public VMSVersioningFTPEntryParser()
    064    {
    065        this(null);
    066    }
    067
    068    /**
    069     * This constructor allows the creation of a VMSVersioningFTPEntryParser
    070     * object with something other than the default configuration.
    071     *
    072     * @param config The {@link FTPClientConfig configuration} object used to
    073     * configure this parser.
    074     * @exception IllegalArgumentException
    075     * Thrown if the regular expression is unparseable.  Should not be seen
    076     * under normal conditions.  It it is seen, this is a sign that
    077     * <code>REGEX</code> is  not a valid regular expression.
    078     * @since 1.4
    079     */
    080    public VMSVersioningFTPEntryParser(FTPClientConfig config)
    081    {
    082        super();
    083        configure(config);
    084        try
    085        {
    086            //_preparse_matcher_ = new Perl5Matcher();
    087            _preparse_pattern_ = Pattern.compile(PRE_PARSE_REGEX);
    088        }
    089        catch (PatternSyntaxException pse)
    090        {
    091            throw new IllegalArgumentException (
    092                "Unparseable regex supplied:  " + PRE_PARSE_REGEX);
    093        }
    094
    095   }
    096
    097    /**
    098     * Implement hook provided for those implementers (such as
    099     * 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 */