FTPFileEntryParserImpl.java

/*
 * Copyright 2010 netling project <http://netling.org>
 *
 * 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.
 *
 * This file may incorporate work covered by the following copyright and
 * permission notice:
 *
 *     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.netling.ftp;

import java.io.BufferedReader;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;

/**
 * This abstract class implements both the older FTPFileListParser and
 * newer FTPFileEntryParser interfaces with default functionality.
 * All the classes in the parser subpackage inherit from this.
 *
 */
public abstract class FTPFileEntryParserImpl
    implements FTPFileEntryParser
{
    /**
     * The constructor for a FTPFileEntryParserImpl object.
     */
    public FTPFileEntryParserImpl()
    {
    }

    /**
     * Reads the next entry using the supplied BufferedReader object up to
     * whatever delemits one entry from the next.  This default implementation
     * simply calls BufferedReader.readLine().
     *
     * @param reader The BufferedReader object from which entries are to be
     * read.
     *
     * @return A string representing the next ftp entry or null if none found.
     * @exception java.io.IOException thrown on any IO Error reading from the reader.
     */
    public String readNextEntry(BufferedReader reader) throws IOException
    {
        return reader.readLine();
    }
    /**
     * This method is a hook for those implementors (such as
     * VMSVersioningFTPEntryParser, and possibly others) which need to
     * perform some action upon the FTPFileList after it has been created
     * from the server stream, but before any clients see the list.
     *
     * This default implementation removes entries that do not parse as files.
     *
     * @param original Original list after it has been created from the server stream
     *
     * @return <code>original</code> unmodified.
     */
     public List<String> preParse(List<String> original) {
         Iterator<String> it = original.iterator();
         while (it.hasNext()){
            String entry = it.next();
            if (null == parseFTPEntry(entry)) {
                it.remove();
            }
         }
         return original;
     }
}