src/main/java/org/apache/commons/net/ftp/parser/CompositeFileEntryParser.java

/*
 * 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 org.apache.commons.net.ftp.FTPFile;
import org.apache.commons.net.ftp.FTPFileEntryParser;
import org.apache.commons.net.ftp.FTPFileEntryParserImpl;

/**
 * This implementation allows to pack some FileEntryParsers together
 * and handle the case where to returned dirstyle isnt clearly defined.
 * The matching parser will be cached.
 * If the cached parser wont match due to the server changed the dirstyle,
 * a new matching parser will be searched.
 *
 * @author Mario Ivankovits <mario@ops.co.at>
 */
public class CompositeFileEntryParser extends FTPFileEntryParserImpl
{
    private final FTPFileEntryParser[] ftpFileEntryParsers;
    private FTPFileEntryParser cachedFtpFileEntryParser;

    public CompositeFileEntryParser(FTPFileEntryParser[] ftpFileEntryParsers)
    {
        super();

        this.cachedFtpFileEntryParser = null;
        this.ftpFileEntryParsers = ftpFileEntryParsers;
    }

    public FTPFile parseFTPEntry(String listEntry)
    {
        if (cachedFtpFileEntryParser != null)
        {
            FTPFile matched = cachedFtpFileEntryParser.parseFTPEntry(listEntry);
            if (matched != null)
            {
                return matched;
            }
        }
        else
        {
            for (FTPFileEntryParser ftpFileEntryParser : ftpFileEntryParsers)
            {
                FTPFile matched = ftpFileEntryParser.parseFTPEntry(listEntry);
                if (matched != null)
                {
                    cachedFtpFileEntryParser = ftpFileEntryParser;
                    return matched;
                }
            }
        }
        return null;
    }
}