/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.net.ftp.parser;
import java.util.HashMap;
import java.util.List;
import java.util.ListIterator;
import java.util.regex.MatchResult;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;
import org.apache.commons.net.ftp.FTPClientConfig;
/**
* Special implementation VMSFTPEntryParser with versioning turned on.
* This parser removes all duplicates and only leaves the version with the highest
* version number for each filename.
*
* This is a sample of VMS LIST output
*
* "1-JUN.LIS;1 9/9 2-JUN-1998 07:32:04 [GROUP,OWNER] (RWED,RWED,RWED,RE)",
* "1-JUN.LIS;2 9/9 2-JUN-1998 07:32:04 [GROUP,OWNER] (RWED,RWED,RWED,RE)",
* "DATA.DIR;1 1/9 2-JUN-1998 07:32:04 [GROUP,OWNER] (RWED,RWED,RWED,RE)",
* <P>
*
* @author <a href="Winston.Ojeda@qg.com">Winston Ojeda</a>
* @author <a href="sestegra@free.fr">Stephane ESTE-GRACIAS</a>
* @version $Id: VMSVersioningFTPEntryParser.java 636854 2008-03-13 19:55:01Z sebb $
*
* @see org.apache.commons.net.ftp.FTPFileEntryParser FTPFileEntryParser (for usage instructions)
*/
public class VMSVersioningFTPEntryParser extends VMSFTPEntryParser
{
private Matcher _preparse_matcher_;
private Pattern _preparse_pattern_;
private static final String PRE_PARSE_REGEX =
"(.*);([0-9]+)\\s*.*";
/**
* Constructor for a VMSFTPEntryParser object. Sets the versioning member
* to the supplied value.
*
* @exception IllegalArgumentException
* Thrown if the regular expression is unparseable. Should not be seen
* under normal conditions. It it is seen, this is a sign that
* <code>REGEX</code> is not a valid regular expression.
*/
public VMSVersioningFTPEntryParser()
{
this(null);
}
/**
* This constructor allows the creation of a VMSVersioningFTPEntryParser
* object with something other than the default configuration.
*
* @param config The {@link FTPClientConfig configuration} object used to
* configure this parser.
* @exception IllegalArgumentException
* Thrown if the regular expression is unparseable. Should not be seen
* under normal conditions. It it is seen, this is a sign that
* <code>REGEX</code> is not a valid regular expression.
* @since 1.4
*/
public VMSVersioningFTPEntryParser(FTPClientConfig config)
{
super();
configure(config);
try
{
//_preparse_matcher_ = new Perl5Matcher();
_preparse_pattern_ = Pattern.compile(PRE_PARSE_REGEX);
}
catch (PatternSyntaxException pse)
{
throw new IllegalArgumentException (
"Unparseable regex supplied: " + PRE_PARSE_REGEX);
}
}
private static class NameVersion {
String name;
int versionNumber;
NameVersion(String name, String vers) {
this.name = name;
this.versionNumber = Integer.parseInt(vers);
}
}
/**
* Implement hook provided for those implementers (such as
* VMSVersioningFTPEntryParser, and possibly others) which return
* multiple files with the same name to remove the duplicates ..
*
* @param original Original list
*
* @return Original list purged of duplicates
*/
@Override
public List<String> preParse(List<String> original) {
original = super.preParse(original);
HashMap<String, NameVersion> existingEntries = new HashMap<String, NameVersion>();
ListIterator<String> iter = original.listIterator();
while (iter.hasNext()) {
String entry = iter.next().trim();
MatchResult result = null;
_preparse_matcher_ = _preparse_pattern_.matcher(entry);
if (_preparse_matcher_.matches()) {
result = _preparse_matcher_.toMatchResult();
String name = result.group(1);
String version = result.group(2);
NameVersion nv = new NameVersion(name, version);
NameVersion existing = existingEntries.get(name);
if (null != existing) {
if (nv.versionNumber < existing.versionNumber) {
iter.remove(); // removal removes from original list.
continue;
}
}
existingEntries.put(name, nv);
}
}
// we've now removed all entries less than with less than the largest
// version number for each name that were listed after the largest.
// we now must remove those with smaller than the largest version number
// for each name that were found before the largest
while (iter.hasPrevious()) {
String entry = iter.previous().trim();
MatchResult result = null;
_preparse_matcher_ = _preparse_pattern_.matcher(entry);
if (_preparse_matcher_.matches()) {
result = _preparse_matcher_.toMatchResult();
String name = result.group(1);
String version = result.group(2);
NameVersion nv = new NameVersion(name, version);
NameVersion existing = existingEntries.get(name);
if (null != existing) {
if (nv.versionNumber < existing.versionNumber) {
iter.remove(); // removal removes from original list.
}
}
}
}
return original;
}
@Override
protected boolean isVersioning() {
return true;
}
}
/* Emacs configuration
* Local variables: **
* mode: java **
* c-basic-offset: 4 **
* indent-tabs-mode: nil **
* End: **
*/