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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.vfs.provider.sftp;
18  
19  import com.jcraft.jsch.ChannelSftp;
20  import com.jcraft.jsch.JSchException;
21  import com.jcraft.jsch.Session;
22  import com.jcraft.jsch.SftpException;
23  import org.apache.commons.vfs.FileName;
24  import org.apache.commons.vfs.FileObject;
25  import org.apache.commons.vfs.FileSystem;
26  import org.apache.commons.vfs.FileSystemException;
27  import org.apache.commons.vfs.FileSystemOptions;
28  import org.apache.commons.vfs.UserAuthenticationData;
29  import org.apache.commons.vfs.util.UserAuthenticatorUtils;
30  import org.apache.commons.vfs.provider.AbstractFileSystem;
31  import org.apache.commons.vfs.provider.GenericFileName;
32  
33  import java.io.IOException;
34  import java.util.Collection;
35  
36  /***
37   * Represents the files on an SFTP server.
38   *
39   * @author <a href="mailto:adammurdoch@apache.org">Adam Murdoch</a>
40   * @version $Revision: 480428 $ $Date: 2006-11-29 07:15:24 +0100 (Mi, 29 Nov 2006) $
41   */
42  public class SftpFileSystem
43      extends AbstractFileSystem
44      implements FileSystem
45  {
46  
47  	private Session session;
48      // private final JSch jSch;
49      private ChannelSftp idleChannel;
50  
51      protected SftpFileSystem(final GenericFileName rootName,
52                               final Session session,
53                               final FileSystemOptions fileSystemOptions)
54      {
55          super(rootName, null, fileSystemOptions);
56          this.session = session;
57      }
58  
59      protected void doCloseCommunicationLink()
60      {
61          if (idleChannel != null)
62          {
63              idleChannel.disconnect();
64              idleChannel = null;
65          }
66  
67          if (session != null)
68          {
69              session.disconnect();
70              session = null;
71          }
72      }
73  
74      /***
75       * Returns an SFTP channel to the server.
76       */
77      protected ChannelSftp getChannel() throws IOException
78      {
79          if (this.session == null)
80          {
81              // channel closed. e.g. by freeUnusedResources, but now we need it again
82              Session session;
83  			UserAuthenticationData authData = null;
84  			try
85              {
86                  final GenericFileName rootName = (GenericFileName) getRootName();
87  
88  				authData = UserAuthenticatorUtils.authenticate(getFileSystemOptions(), SftpFileProvider.AUTHENTICATOR_TYPES);
89  
90  				session = SftpClientFactory.createConnection(
91  					rootName.getHostName(),
92  					rootName.getPort(),
93  					UserAuthenticatorUtils.getData(authData, UserAuthenticationData.USERNAME, UserAuthenticatorUtils.toChar(rootName.getUserName())),
94  					UserAuthenticatorUtils.getData(authData, UserAuthenticationData.PASSWORD, UserAuthenticatorUtils.toChar(rootName.getPassword())),
95  					getFileSystemOptions());
96              }
97              catch (final Exception e)
98              {
99                  throw new FileSystemException("vfs.provider.sftp/connect.error",
100                     getRootName(),
101                     e);
102             }
103 			finally
104 			{
105 				UserAuthenticatorUtils.cleanup(authData);
106 			}
107 
108 			this.session = session;
109         }
110 
111         try
112         {
113             // Use the pooled channel, or create a new one
114             final ChannelSftp channel;
115             if (idleChannel != null)
116             {
117                 channel = idleChannel;
118                 idleChannel = null;
119             }
120             else
121             {
122                 channel = (ChannelSftp) session.openChannel("sftp");
123                 channel.connect();
124 
125                 Boolean userDirIsRoot = SftpFileSystemConfigBuilder.getInstance().getUserDirIsRoot(getFileSystemOptions());
126                 String workingDirectory = getRootName().getPath();
127                 if (workingDirectory != null && (userDirIsRoot == null || !userDirIsRoot.booleanValue()))
128                 {
129                     try
130                     {
131                         channel.cd(workingDirectory);
132                     }
133                     catch (SftpException e)
134                     {
135                         throw new FileSystemException("vfs.provider.sftp/change-work-directory.error", workingDirectory);
136                     }
137                 }
138             }
139 
140             return channel;
141         }
142         catch (final JSchException e)
143         {
144             throw new FileSystemException("vfs.provider.sftp/connect.error",
145                 getRootName(),
146                 e);
147         }
148     }
149 
150     /***
151      * Returns a channel to the pool.
152      */
153     protected void putChannel(final ChannelSftp channel)
154     {
155         if (idleChannel == null)
156         {
157         	// put back the channel only if it is still connected
158         	if (channel.isConnected() && !channel.isClosed())
159         	{
160         		idleChannel = channel;
161         	}
162         }
163         else
164         {
165             channel.disconnect();
166         }
167     }
168 
169     /***
170      * Adds the capabilities of this file system.
171      */
172     protected void addCapabilities(final Collection caps)
173     {
174         caps.addAll(SftpFileProvider.capabilities);
175     }
176 
177     /***
178      * Creates a file object.  This method is called only if the requested
179      * file is not cached.
180      */
181     protected FileObject createFile(final FileName name)
182         throws FileSystemException
183     {
184         return new SftpFileObject(name, this);
185     }
186 
187     /***
188      * last mod time is only a int and in seconds, thus can be off by 999
189      *
190      * @return 1000
191      */
192     public double getLastModTimeAccuracy()
193     {
194         return 1000L;
195     }
196 }