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/*
* Copyright 2001-2004 The Apache Software Foundation
*
* Licensed 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 org.apache.oro.text.regex.MalformedPatternException;
import org.apache.oro.text.regex.MatchResult;
import org.apache.oro.text.regex.Pattern;
import org.apache.oro.text.regex.Perl5Compiler;
import org.apache.oro.text.regex.Perl5Matcher;
/**
* 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)",
*
*
* @author Winston Ojeda
* @author Steve Cohen
* @author Stephane ESTE-GRACIAS
* @version $Id: VMSVersioningFTPEntryParser.java,v 1.8 2004/04/22 00:48:07 scohen Exp $
*
* @see org.apache.commons.net.ftp.FTPFileEntryParser FTPFileEntryParser (for usage instructions)
*/
public class VMSVersioningFTPEntryParser extends VMSFTPEntryParser
{
private Perl5Matcher _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
* REGEX is not a valid regular expression.
*/
public VMSVersioningFTPEntryParser()
{
super();
try
{
_preparse_matcher_ = new Perl5Matcher();
_preparse_pattern_ = new Perl5Compiler().compile(PRE_PARSE_REGEX);
}
catch (MalformedPatternException e)
{
throw new IllegalArgumentException (
"Unparseable regex supplied: " + PRE_PARSE_REGEX);
}
}
private 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
*/
public List preParse(List original) {
original = super.preParse(original);
HashMap existingEntries = new HashMap();
ListIterator iter = original.listIterator();
while (iter.hasNext()) {
String entry = ((String)iter.next()).trim();
MatchResult result = null;
if (_preparse_matcher_.matches(entry, _preparse_pattern_)) {
result = _preparse_matcher_.getMatch();
String name = result.group(1);
String version = result.group(2);
NameVersion nv = new NameVersion(name, version);
NameVersion existing = (NameVersion) 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 = ((String)iter.previous()).trim();
MatchResult result = null;
if (_preparse_matcher_.matches(entry, _preparse_pattern_)) {
result = _preparse_matcher_.getMatch();
String name = result.group(1);
String version = result.group(2);
NameVersion nv = new NameVersion(name, version);
NameVersion existing = (NameVersion) existingEntries.get(name);
if (null != existing) {
if (nv.versionNumber < existing.versionNumber) {
iter.remove(); // removal removes from original list.
}
}
}
}
return original;
}
protected boolean isVersioning() {
return true;
}
}
/* Emacs configuration
* Local variables: **
* mode: java **
* c-basic-offset: 4 **
* indent-tabs-mode: nil **
* End: **
*/
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