Package org.apache.sshd.client.channel

Class AbstractClientChannel

java.lang.Object

org.apache.sshd.common.util.logging.AbstractLoggingBean

org.apache.sshd.common.util.closeable.IoBaseCloseable

org.apache.sshd.common.util.closeable.AbstractCloseable

org.apache.sshd.common.util.closeable.AbstractInnerCloseable

org.apache.sshd.common.channel.AbstractChannel

org.apache.sshd.client.channel.AbstractClientChannel

All Implemented Interfaces:

Closeable, AutoCloseable, Channel, ClientChannel, ClientSessionHolder, AttributeRepository, AttributeStore, Channel, ChannelIdentifier, ChannelListenerManager, StreamingChannel, ChannelStreamWriterResolver, ChannelStreamWriterResolverManager, Closeable, PropertyResolver, SessionContextHolder, SessionHolder<Session>, ExecutorServiceCarrier

Direct Known Subclasses:

AgentForwardedChannel, AgentForwardedChannel, ChannelDirectTcpip, ChannelForwardedX11, ChannelSession, TcpipClientChannel

public abstract class AbstractClientChannel
extends AbstractChannel
implements ClientChannel

TODO Add javadoc

Author:

Apache MINA SSHD Project

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.sshd.common.channel.AbstractChannel

AbstractChannel.GracefulChannelCloseable, AbstractChannel.GracefulState

Nested classes/interfaces inherited from class org.apache.sshd.common.util.closeable.AbstractCloseable

AbstractCloseable.State

Nested classes/interfaces inherited from interface org.apache.sshd.common.AttributeRepository

AttributeRepository.AttributeKey<T extends Object>

Nested classes/interfaces inherited from interface org.apache.sshd.common.channel.StreamingChannel

StreamingChannel.Streaming

Field Summary

Fields

Modifier and Type	Field	Description
protected ChannelAsyncInputStream	asyncErr
protected ChannelAsyncOutputStream	asyncIn
protected ChannelAsyncInputStream	asyncOut
protected OutputStream	err
protected final AtomicReference<String>	exitSignalHolder
protected final AtomicReference<Integer>	exitStatusHolder
protected InputStream	in
protected InputStream	invertedErr
protected OutputStream	invertedIn
protected InputStream	invertedOut
protected final AtomicBoolean	opened
protected String	openFailureLang
protected String	openFailureMsg
protected int	openFailureReason
protected OpenFuture	openFuture
protected OutputStream	out
protected boolean	redirectErrorStream
protected StreamingChannel.Streaming	streaming

Fields inherited from class org.apache.sshd.common.channel.AbstractChannel

channelListenerProxy, channelListeners, closeSignaled, eofReceived, eofSent, gracefulFuture, gracefulState, initialized, RESPONSE_BUFFER_GROWTH_FACTOR, service, unregisterSignaled

Fields inherited from class org.apache.sshd.common.util.closeable.AbstractCloseable

closeFuture, futureLock, state

Fields inherited from class org.apache.sshd.common.util.logging.AbstractLoggingBean

log

Fields inherited from interface org.apache.sshd.common.channel.Channel

CHANNEL_EXEC, CHANNEL_SHELL, CHANNEL_SUBSYSTEM

Fields inherited from interface org.apache.sshd.common.channel.throttle.ChannelStreamWriterResolver

NONE

Fields inherited from interface org.apache.sshd.common.PropertyResolver

EMPTY

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractClientChannel(String type)
protected	AbstractClientChannel(String type, Collection<? extends RequestHandler<Channel>> handlers)

Method Summary

Modifier and Type	Method	Description
protected void	addChannelSignalRequestHandlers(EventNotifier<String> notifier)
protected abstract void	doOpen()
protected void	doWriteData(byte[] data, int off, long len)
protected void	doWriteExtendedData(byte[] data, int off, long len)
IoInputStream	getAsyncErr()
IoOutputStream	getAsyncIn()
IoInputStream	getAsyncOut()
Set<ClientChannelEvent>	getChannelState()
String	getChannelType()
OutputStream	getErr()
String	getExitSignal()
Integer	getExitStatus()
InputStream	getIn()
protected Closeable	getInnerCloseable()
InputStream	getInvertedErr()	Obtains an InputStream to read received SshConstants.SSH_MSG_CHANNEL_EXTENDED_DATA data directly from the channel.
OutputStream	getInvertedIn()	Obtains an OutputStream to send data directly to the remote end of the channel.
InputStream	getInvertedOut()	Obtains an InputStream to read received SshConstants.SSH_MSG_CHANNEL_DATA data directly from the channel.
OutputStream	getOut()
StreamingChannel.Streaming	getStreaming()
void	handleOpenFailure(Buffer buffer)	For a client channel, this method will be called internally by the session when the server has rejected this channel opening.
void	handleOpenSuccess(long recipient, long rwSize, long packetSize, Buffer buffer)	For a client channel, this method will be called internally by the session when the confirmation has been received.
void	handleWindowAdjust(Buffer buffer)	Invoked when SSH_MSG_CHANNEL_WINDOW_ADJUST received
boolean	isRedirectErrorStream()
protected boolean	mayWrite()
OpenFuture	open()
OpenFuture	open(long recipient, long rwSize, long packetSize, Buffer buffer)	For a server channel, this method will actually open the channel
void	setErr(OutputStream err)	Sets an output stream for the channel to write received SshConstants.SSH_MSG_CHANNEL_EXTENDED_DATA data to.
void	setIn(InputStream in)	Sets an InputStream that will be read by this channel and forwarded to the remote channel.
void	setOut(OutputStream out)	Sets an output stream for the channel to write received SshConstants.SSH_MSG_CHANNEL_DATA data to.
void	setRedirectErrorStream(boolean redirectErrorStream)	Defines whether to redirect the error stream into the output stream; has no effect if ClientChannel.setErr(OutputStream) has also been called by the time the channel is opened.
void	setStreaming(StreamingChannel.Streaming streaming)
protected <C extends Collection<ClientChannelEvent>> C	updateCurrentChannelState(C state)
Set<ClientChannelEvent>	waitFor(Collection<ClientChannelEvent> mask, long timeout)	Waits until any of the specified events in the mask is signaled

Methods inherited from class org.apache.sshd.common.channel.AbstractChannel

addChannelListener, addPendingRequest, addRequestHandler, attributeKeys, clearAttributes, computeAttributeIfAbsent, configureWindow, getAttribute, getAttributesCount, getChannelId, getChannelListenerProxy, getChannelStreamWriterResolver, getExecutorService, getLocalWindow, getParentPropertyResolver, getProperties, getRecipient, getRemoteWindow, getRequestHandlers, getSession, handleChannelRegistrationResult, handleChannelRequest, handleChannelUnregistration, handleClose, handleData, handleEof, handleExtendedData, handleFailure, handleInternalRequest, handleRequest, handleSuccess, handleUnknownChannelRequest, init, invokeChannelSignaller, isEofSent, isEofSignalled, isInitialized, notifyStateChanged, notifyStateChanged, preClose, removeAttribute, removeChannelListener, removePendingRequest, removeRequestHandler, resolveChannelStreamWriterResolver, sendEof, sendResponse, sendWindowAdjust, setAttribute, setChannelStreamWriterResolver, setRecipient, signalChannelClosed, signalChannelClosed, signalChannelInitialized, signalChannelInitialized, signalChannelOpenFailure, signalChannelOpenFailure, signalChannelOpenSuccess, signalChannelOpenSuccess, toString, validateIncomingDataSize, writePacket

Methods inherited from class org.apache.sshd.common.util.closeable.AbstractInnerCloseable

doCloseGracefully, doCloseImmediately

Methods inherited from class org.apache.sshd.common.util.closeable.AbstractCloseable

addCloseFutureListener, builder, close, getFutureLock, isClosed, isClosing, removeCloseFutureListener

Methods inherited from class org.apache.sshd.common.util.logging.AbstractLoggingBean

debug, debug, debug, debug, debug, error, error, error, error, error, getSimplifiedLogger, info, info, warn, warn, warn, warn, warn, warn, warn, warn

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.sshd.common.AttributeRepository

attributeKeys, getAttribute, getAttributesCount

Methods inherited from interface org.apache.sshd.common.AttributeStore

clearAttributes, computeAttributeIfAbsent, removeAttribute, setAttribute

Methods inherited from interface org.apache.sshd.common.channel.Channel

addRequestHandler, addRequestHandlers, getLocalWindow, getRecipient, getRemoteWindow, getRequestHandlers, handleChannelRegistrationResult, handleChannelUnregistration, handleClose, handleData, handleEof, handleExtendedData, handleFailure, handleRequest, handleSuccess, init, isEofSignalled, isInitialized, removeRequestHandler, removeRequestHandlers, resolveAttribute, writePacket

Methods inherited from interface org.apache.sshd.common.channel.ChannelIdentifier

getChannelId

Methods inherited from interface org.apache.sshd.common.channel.ChannelListenerManager

addChannelListener, getChannelListenerProxy, removeChannelListener

Methods inherited from interface org.apache.sshd.common.channel.throttle.ChannelStreamWriterResolverManager

getChannelStreamWriterResolver, resolveChannelStreamWriter, resolveChannelStreamWriterResolver, setChannelStreamWriterResolver

Methods inherited from interface org.apache.sshd.client.channel.ClientChannel

getClientSession, waitFor

Methods inherited from interface org.apache.sshd.common.Closeable

addCloseFutureListener, close, close, isClosed, isClosing, isOpen, removeCloseFutureListener

Methods inherited from interface org.apache.sshd.common.PropertyResolver

getBoolean, getBooleanProperty, getCharset, getInteger, getIntProperty, getLong, getLongProperty, getObject, getParentPropertyResolver, getProperties, getString, getStringProperty, isEmpty

Methods inherited from interface org.apache.sshd.common.session.SessionHolder

getSession, getSessionContext

Field Details

opened

protected final AtomicBoolean opened

streaming

protected StreamingChannel.Streaming streaming

asyncIn

protected ChannelAsyncOutputStream asyncIn

asyncOut

protected ChannelAsyncInputStream asyncOut

asyncErr

protected ChannelAsyncInputStream asyncErr

in

protected InputStream in

invertedIn

protected OutputStream invertedIn

out

protected OutputStream out

invertedOut

protected InputStream invertedOut

err

protected OutputStream err

invertedErr

protected InputStream invertedErr

redirectErrorStream

protected boolean redirectErrorStream

exitStatusHolder

protected final AtomicReference<Integer> exitStatusHolder

exitSignalHolder

protected final AtomicReference<String> exitSignalHolder

openFailureReason

protected int openFailureReason

openFailureMsg

protected String openFailureMsg

openFailureLang

protected String openFailureLang

openFuture

protected OpenFuture openFuture

Constructor Details

AbstractClientChannel

protected AbstractClientChannel(String type)

AbstractClientChannel

protected AbstractClientChannel(String type,
 Collection<? extends RequestHandler<Channel>> handlers)

Method Details

addChannelSignalRequestHandlers

protected void addChannelSignalRequestHandlers(EventNotifier<String> notifier)

getChannelType

public String getChannelType()

Specified by:

getChannelType in interface ClientChannel

Returns:

The type of channel reported when it was created

getStreaming

public StreamingChannel.Streaming getStreaming()

Specified by:

getStreaming in interface StreamingChannel

setStreaming

public void setStreaming(StreamingChannel.Streaming streaming)

Specified by:

setStreaming in interface StreamingChannel

getAsyncIn

public IoOutputStream getAsyncIn()

Specified by:

getAsyncIn in interface ClientChannel

getAsyncOut

public IoInputStream getAsyncOut()

Specified by:

getAsyncOut in interface ClientChannel

getAsyncErr

public IoInputStream getAsyncErr()

Specified by:

getAsyncErr in interface ClientChannel

getInvertedIn

public OutputStream getInvertedIn()

Description copied from interface: ClientChannel

Obtains an OutputStream to send data directly to the remote end of the channel. This can be used instead of using ClientChannel.setIn(InputStream) method and having the channel polling for data in that stream.

When the channel closes, it will close the returned stream.

This method should be called only after the channel has been opened.

Specified by:

getInvertedIn in interface ClientChannel

Returns:

an OutputStream for sending data, or null if an input stream was set via ClientChannel.setIn(InputStream)

See Also:

• ClientChannel.setIn(InputStream)

getIn

public InputStream getIn()

setIn

public void setIn(InputStream in)

Description copied from interface: ClientChannel

Sets an InputStream that will be read by this channel and forwarded to the remote channel. Note that using such a stream will create an additional thread for pumping the stream which will only be able to end when that stream is actually closed or EOF on the stream is reached. It is recommended to use the ClientChannel.getInvertedIn() method instead and write data directly.

The stream must be set before the channel is opened. When the channel closes, it will close the given stream.

Specified by:

setIn in interface ClientChannel

Parameters:

in - an InputStream to be polled and forwarded

See Also:

• ClientChannel.getInvertedIn()

getInvertedOut

public InputStream getInvertedOut()

Description copied from interface: ClientChannel

Obtains an InputStream to read received SshConstants.SSH_MSG_CHANNEL_DATA data directly from the channel. This is an alternative to ClientChannel.setOut(OutputStream). If the error stream is redirected to the output stream via setRedirectErrorStream(true), this stream will also receive SshConstants.SSH_MSG_CHANNEL_EXTENDED_DATA data.

When the channel closes, it will not close the returned stream. It is the caller's responsibility to close the returned stream if needed. Closing the stream while the channel is open may cause the channel to be closed forcibly if more data arrives. The stream remains open after the channel has closed, so that the caller can read the last arrived data even afterwards.

As with all external processes, the application should read this stream to avoid that the channel blocks when the stream's buffer is full. The buffer size for the returned stream is bounded by the channel's local window size. If the caller does not read this stream, the channel will block once the local window is exhausted.

This method should be called only after the channel has been opened.

Specified by:

getInvertedOut in interface ClientChannel

Returns:

an InputStream for reading received data, or null if an output stream was set via ClientChannel.setOut(OutputStream)

See Also:

• ClientChannel.setOut(OutputStream)
• ClientChannel.setRedirectErrorStream(boolean)

getOut

public OutputStream getOut()

setOut

public void setOut(OutputStream out)

Description copied from interface: ClientChannel

Sets an output stream for the channel to write received SshConstants.SSH_MSG_CHANNEL_DATA data to. For remote command execution, this is typically the remote command's stdout. If the error stream is redirected to the output stream via setRedirectErrorStream(true), this stream will also receive SshConstants.SSH_MSG_CHANNEL_EXTENDED_DATA data.

The stream must be set before the channel is opened. When the channel closes, it will close the given stream.

If no stream is set by the time the channel is opened, the channel will internally forward data to a stream that can be read via the InputStream obtained via ClientChannel.getInvertedOut().

Specified by:

setOut in interface ClientChannel

Parameters:

out - the OutputStream

See Also:

• ClientChannel.getInvertedOut()
• ClientChannel.setRedirectErrorStream(boolean)

getInvertedErr

public InputStream getInvertedErr()

Description copied from interface: ClientChannel

Obtains an InputStream to read received SshConstants.SSH_MSG_CHANNEL_EXTENDED_DATA data directly from the channel. This is an alternative to ClientChannel.setErr(OutputStream). If the error stream is redirected to the output stream via setRedirectErrorStream(true), the returned stream will not receive any data and be always at EOF.

When the channel closes, it will not close the returned stream. It is the caller's responsibility to close the returned stream if needed. Closing the stream while the channel is open may cause the channel to be closed forcibly if more data arrives. The stream remains open after the channel has closed, so that the caller can read the last arrived data even afterwards.

As with all external processes, the application should read this stream (unless it was redirected) to avoid that the channel blocks when the stream's buffer is full. The buffer size for the returned stream is bounded by the channel's local window size. If the caller does not read this stream, the channel will block once the local window is exhausted.

This method should be called only after the channel has been opened.

Specified by:

getInvertedErr in interface ClientChannel

Returns:

an InputStream for reading received data, or null if an output stream was set via ClientChannel.setErr(OutputStream)

See Also:

• ClientChannel.setErr(OutputStream)
• ClientChannel.setRedirectErrorStream(boolean)

getErr

public OutputStream getErr()

setErr

public void setErr(OutputStream err)

Description copied from interface: ClientChannel

Sets an output stream for the channel to write received SshConstants.SSH_MSG_CHANNEL_EXTENDED_DATA data to. For remote command execution, this is typically the remote command's stderr.

The stream must be set before the channel is opened. When the channel closes, it will close the given stream.

If no stream is set by the time the channel is opened, the channel will internally forward data to a stream that can be read via the InputStream obtained via ClientChannel.getInvertedErr(). (Or it might forward the data to the output stream if setRedirectErrorStream(true) is set.)

Specified by:

setErr in interface ClientChannel

Parameters:

err - the OutputStream

See Also:

• ClientChannel.getInvertedErr()
• ClientChannel.setRedirectErrorStream(boolean)

isRedirectErrorStream

public boolean isRedirectErrorStream()

setRedirectErrorStream

public void setRedirectErrorStream(boolean redirectErrorStream)

Description copied from interface: ClientChannel

Defines whether to redirect the error stream into the output stream; has no effect if ClientChannel.setErr(OutputStream) has also been called by the time the channel is opened.

Specified by:

setRedirectErrorStream in interface ClientChannel

Parameters:

redirectErrorStream - whether to redirect the error stream to the output stream.

getInnerCloseable

protected Closeable getInnerCloseable()

Overrides:

getInnerCloseable in class AbstractChannel

waitFor

public Set<ClientChannelEvent> waitFor(Collection<ClientChannelEvent> mask,
 long timeout)

Description copied from interface: ClientChannel

Waits until any of the specified events in the mask is signaled

Specified by:

waitFor in interface ClientChannel

Parameters:

mask - The ClientChannelEvents mask

timeout - The timeout to wait (msec.) - if non-positive then forever

Returns:

The actual signaled event - includes ClientChannelEvent.TIMEOUT if timeout expired before the expected event was signaled

getChannelState

public Set<ClientChannelEvent> getChannelState()

Specified by:

getChannelState in interface ClientChannel

Returns:

A snapshot of the current channel state

See Also:

• ClientChannel.waitFor(Collection, long)

updateCurrentChannelState

protected <C extends Collection<ClientChannelEvent>>
C updateCurrentChannelState(C state)

open

public OpenFuture open()
                throws IOException

Specified by:

open in interface ClientChannel

Throws:

IOException

open

public OpenFuture open(long recipient,
 long rwSize,
 long packetSize,
 Buffer buffer)

Description copied from interface: Channel

For a server channel, this method will actually open the channel

Specified by:

open in interface Channel

Parameters:

recipient - Recipient identifier (UINT32 represented as a long)

rwSize - Read/Write window size (uint32)

packetSize - Preferred maximum packet size (uint32)

buffer - Incoming Buffer that triggered the call. Note: the buffer's read position is exactly after the information that read to this call was decoded

Returns:

An OpenFuture for the channel open request

handleOpenSuccess

public void handleOpenSuccess(long recipient,
 long rwSize,
 long packetSize,
 Buffer buffer)

Description copied from interface: Channel

For a client channel, this method will be called internally by the session when the confirmation has been received.

Specified by:

handleOpenSuccess in interface Channel

Parameters:

recipient - Recipient identifier (UINT32 represented as a long)

rwSize - Read/Write window size (uint32)

packetSize - Preferred maximum packet size (uint32)

buffer - Incoming Buffer that triggered the call. Note: the buffer's read position is exactly after the information that read to this call was decoded

doOpen

protected abstract void doOpen()
                        throws IOException

Throws:

IOException

handleOpenFailure

public void handleOpenFailure(Buffer buffer)

Description copied from interface: Channel

For a client channel, this method will be called internally by the session when the server has rejected this channel opening.

Specified by:

handleOpenFailure in interface Channel

Parameters:

buffer - Incoming Buffer that triggered the call. Note: the buffer's read position is exactly after the information that read to this call was decoded

doWriteData

protected void doWriteData(byte[] data,
 int off,
 long len)
                    throws IOException

Specified by:

doWriteData in class AbstractChannel

Throws:

IOException

doWriteExtendedData

protected void doWriteExtendedData(byte[] data,
 int off,
 long len)
                            throws IOException

Specified by:

doWriteExtendedData in class AbstractChannel

Throws:

IOException

handleWindowAdjust

public void handleWindowAdjust(Buffer buffer)
                        throws IOException

Description copied from interface: Channel

Invoked when SSH_MSG_CHANNEL_WINDOW_ADJUST received

Specified by:

handleWindowAdjust in interface Channel

Overrides:

handleWindowAdjust in class AbstractChannel

Parameters:

buffer - The rest of the message data Buffer after decoding the channel identifiers

Throws:

IOException - If failed to handle the message

mayWrite

protected boolean mayWrite()

Overrides:

mayWrite in class AbstractChannel

getExitStatus

public Integer getExitStatus()

Specified by:

getExitStatus in interface ClientChannel

Returns:

The signaled exit status via "exit-status" request - null if not signaled

getExitSignal

public String getExitSignal()

Specified by:

getExitSignal in interface ClientChannel

Returns:

The signaled exit signal via "exit-signal" - null if not signaled