Package org.apache.commons.vfs2.provider.sftp

Class SftpFileSystem

java.lang.Object

org.apache.commons.vfs2.provider.AbstractVfsComponent

org.apache.commons.vfs2.provider.AbstractFileSystem

org.apache.commons.vfs2.provider.sftp.SftpFileSystem

All Implemented Interfaces:

Closeable, AutoCloseable, FileSystem, VfsComponent

public class SftpFileSystem
extends AbstractFileSystem

Represents the files on an SFTP server.

Field Summary

Fields

Modifier and Type	Field	Description
private final Duration	connectTimeout
private static final int	EXEC_BUFFER_SIZE
private final boolean	execDisabled	Some SFTP-only servers disable the exec channel.
private int[]	groupsIds	Cache for the user groups ids (null when not set)
private com.jcraft.jsch.ChannelSftp	idleChannel
private static final long	LAST_MOD_TIME_ACCURACY
private static final org.apache.commons.logging.Log	LOG
private com.jcraft.jsch.Session	session	Session; never null.
private static final int	SLEEP_MILLIS
private int	uid	Cache for the user ID (-1 when not set)
private static final int	UNIDENTIFED

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	SftpFileSystem(GenericFileName rootName, com.jcraft.jsch.Session session, FileSystemOptions fileSystemOptions)

Method Summary

Modifier and Type	Method	Description
protected void	addCapabilities(Collection<Capability> caps)	Adds the capabilities of this file system.
protected FileObject	createFile(AbstractFileName name)	Creates a file object.
private boolean	detectExecDisabled()	Some SFTP-only servers disable the exec channel.
protected void	doCloseCommunicationLink()	Closes the underlying link used to access the files.
private int	executeCommand(String command, StringBuilder output)	Executes a command and returns the (standard) output through a StringBuilder.
protected com.jcraft.jsch.ChannelSftp	getChannel()	Returns an SFTP channel to the server.
int[]	getGroupsIds()	Gets the (numeric) group IDs.
double	getLastModTimeAccuracy()	Last modification time is only an int and in seconds, thus can be off by 999.
private com.jcraft.jsch.Session	getSession()	Ensures that the session link is established.
int	getUId()	Gets the (numeric) group IDs.
boolean	isExecDisabled()
protected void	putChannel(com.jcraft.jsch.ChannelSftp channelSftp)	Returns a channel to the pool.

Methods inherited from class org.apache.commons.vfs2.provider.AbstractFileSystem

addJunction, addListener, close, closeCommunicationLink, decorateFileObject, doReplicateFile, fireFileChanged, fireFileCreated, fireFileDeleted, getAttribute, getFileFromCache, getFileSystemManager, getFileSystemOptions, getParentLayer, getRoot, getRootName, getRootURI, hasCapability, init, isOpen, isReleaseable, notifyAllStreamsClosed, putFileToCache, removeFileFromCache, removeJunction, removeListener, replicateFile, resolveFile, resolveFile, setAttribute

Methods inherited from class org.apache.commons.vfs2.provider.AbstractVfsComponent

getContext, getLogger, setContext, setLogger

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

LOG

private static final org.apache.commons.logging.Log LOG

UNIDENTIFED

private static final int UNIDENTIFED

See Also:

• Constant Field Values

SLEEP_MILLIS

private static final int SLEEP_MILLIS

See Also:

• Constant Field Values

EXEC_BUFFER_SIZE

private static final int EXEC_BUFFER_SIZE

See Also:

• Constant Field Values

LAST_MOD_TIME_ACCURACY

private static final long LAST_MOD_TIME_ACCURACY

See Also:

• Constant Field Values

session

private volatile com.jcraft.jsch.Session session

Session; never null.

DCL pattern requires that the ivar be volatile.

idleChannel

private volatile com.jcraft.jsch.ChannelSftp idleChannel

connectTimeout

private final Duration connectTimeout

uid

private volatile int uid

Cache for the user ID (-1 when not set)

DCL pattern requires that the ivar be volatile.

groupsIds

private volatile int[] groupsIds

Cache for the user groups ids (null when not set)

DCL pattern requires that the ivar be volatile.

execDisabled

private final boolean execDisabled

Some SFTP-only servers disable the exec channel. When exec is disabled, things like getUId() will always fail.

Constructor Details

SftpFileSystem

protected SftpFileSystem(GenericFileName rootName,
 com.jcraft.jsch.Session session,
 FileSystemOptions fileSystemOptions)

Method Details

addCapabilities

protected void addCapabilities(Collection<Capability> caps)

Adds the capabilities of this file system.

Specified by:

addCapabilities in class AbstractFileSystem

Parameters:

caps - collections of Capabilities, can be immutable.

createFile

protected FileObject createFile(AbstractFileName name)
                         throws FileSystemException

Creates a file object. This method is called only if the requested file is not cached.

Specified by:

createFile in class AbstractFileSystem

Parameters:

name - name referencing the new file.

Returns:

new created FileObject.

Throws:

FileSystemException

detectExecDisabled

private boolean detectExecDisabled()

Some SFTP-only servers disable the exec channel. Attempt to detect this by calling getUid.

doCloseCommunicationLink

protected void doCloseCommunicationLink()

Description copied from class: AbstractFileSystem

Closes the underlying link used to access the files.

Overrides:

doCloseCommunicationLink in class AbstractFileSystem

executeCommand

private int executeCommand(String command,
 StringBuilder output)
                    throws com.jcraft.jsch.JSchException,
IOException

Executes a command and returns the (standard) output through a StringBuilder.

Parameters:

command - The command

output - The output

Returns:

The exit code of the command

Throws:

com.jcraft.jsch.JSchException - if a JSch error is detected.

FileSystemException - if a session cannot be created.

IOException - if an I/O error is detected.

getChannel

protected com.jcraft.jsch.ChannelSftp getChannel()
                                          throws IOException

Returns an SFTP channel to the server.

Returns:

new or reused channel, never null.

Throws:

FileSystemException - if a session cannot be created.

IOException - if an I/O error is detected.

getGroupsIds

public int[] getGroupsIds()
                   throws com.jcraft.jsch.JSchException,
IOException

Gets the (numeric) group IDs.

Returns:

the (numeric) group IDs.

Throws:

com.jcraft.jsch.JSchException - If a problem occurs while retrieving the group IDs.

IOException - if an I/O error is detected.

Since:

2.1

getLastModTimeAccuracy

public double getLastModTimeAccuracy()

Last modification time is only an int and in seconds, thus can be off by 999.

Specified by:

getLastModTimeAccuracy in interface FileSystem

Overrides:

getLastModTimeAccuracy in class AbstractFileSystem

Returns:

1000

getSession

private com.jcraft.jsch.Session getSession()
                                    throws FileSystemException

Ensures that the session link is established.

Throws:

FileSystemException - if a session cannot be created.

getUId

public int getUId()
           throws com.jcraft.jsch.JSchException,
IOException

Gets the (numeric) group IDs.

Returns:

The numeric user ID

Throws:

com.jcraft.jsch.JSchException - If a problem occurs while retrieving the group ID.

IOException - if an I/O error is detected.

Since:

2.1

isExecDisabled

public boolean isExecDisabled()

Returns:

Whether the exec channel is disabled.

See Also:

• execDisabled

putChannel

protected void putChannel(com.jcraft.jsch.ChannelSftp channelSftp)

Returns a channel to the pool.

Parameters:

channelSftp - the SFTP channel.