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