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 */
017package org.apache.commons.vfs2.provider.ftp;
018
019import java.io.IOException;
020import java.util.Collection;
021import java.util.concurrent.atomic.AtomicReference;
022
023import org.apache.commons.logging.Log;
024import org.apache.commons.logging.LogFactory;
025import org.apache.commons.vfs2.Capability;
026import org.apache.commons.vfs2.FileObject;
027import org.apache.commons.vfs2.FileSystemException;
028import org.apache.commons.vfs2.FileSystemOptions;
029import org.apache.commons.vfs2.VfsLog;
030import org.apache.commons.vfs2.provider.AbstractFileName;
031import org.apache.commons.vfs2.provider.AbstractFileSystem;
032import org.apache.commons.vfs2.provider.GenericFileName;
033
034/**
035 * An FTP file system.
036 */
037public class FtpFileSystem extends AbstractFileSystem {
038
039    private static final Log LOG = LogFactory.getLog(FtpFileSystem.class);
040
041    // private final String hostname;
042    // private final int port;
043    // private final String username;
044    // private final String password;
045
046    // An idle client
047    private final AtomicReference<FtpClient> idleClient = new AtomicReference<>();
048
049    /**
050     * Constructs a new instance.
051     *
052     * @param rootName The root of the file system.
053     * @param ftpClient The FtpClient.
054     * @param fileSystemOptions The FileSystemOptions.
055     * @since 2.0 (was protected)
056     */
057    public FtpFileSystem(final GenericFileName rootName, final FtpClient ftpClient,
058            final FileSystemOptions fileSystemOptions) {
059        super(rootName, null, fileSystemOptions);
060        // hostname = rootName.getHostName();
061        // port = rootName.getPort();
062
063        idleClient.set(ftpClient);
064    }
065
066    /**
067     * Adds the capabilities of this file system.
068     */
069    @Override
070    protected void addCapabilities(final Collection<Capability> caps) {
071        caps.addAll(FtpFileProvider.CAPABILITIES);
072    }
073
074    /**
075     * Cleans up the connection to the server.
076     *
077     * @param client The FtpClient.
078     */
079    private void closeConnection(final FtpClient client) {
080        try {
081            // Clean up
082            if (client.isConnected()) {
083                client.disconnect();
084            }
085        } catch (final IOException e) {
086            // getLogger().warn("vfs.provider.ftp/close-connection.error", e);
087            VfsLog.warn(getLogger(), LOG, "vfs.provider.ftp/close-connection.error", e);
088        }
089    }
090
091    /**
092     * Creates a file object.
093     */
094    @Override
095    protected FileObject createFile(final AbstractFileName name) throws FileSystemException {
096        return new FtpFileObject(name, this, getRootName());
097    }
098
099    /**
100     * Gets the wrapper to access this file system.
101     *
102     * @return new instance.
103     * @throws FileSystemException if any error occurs.
104     * @since 2.1
105     */
106    protected FTPClientWrapper createWrapper() throws FileSystemException {
107        return new FTPClientWrapper((GenericFileName) getRoot().getName(), getFileSystemOptions());
108    }
109
110    @Override
111    protected void doCloseCommunicationLink() {
112        final FtpClient idle = idleClient.getAndSet(null);
113        // Clean up the connection
114        if (idle != null) {
115            closeConnection(idle);
116        }
117    }
118
119    /**
120     * Creates an FTP client to use.
121     *
122     * @return An FTPClient.
123     * @throws FileSystemException if an error occurs.
124     */
125    public FtpClient getClient() throws FileSystemException {
126        FtpClient client = idleClient.getAndSet(null);
127
128        if (client == null || !client.isConnected()) {
129            client = createWrapper();
130        }
131
132        return client;
133    }
134
135    /**
136     * Returns an FTP client after use.
137     *
138     * @param client The FTPClient.
139     */
140    public void putClient(final FtpClient client) {
141        // Save client for reuse if none is idle.
142        if (!idleClient.compareAndSet(null, client)) {
143            // An idle client is already present so close the connection.
144            closeConnection(client);
145        }
146    }
147}