Channel (simple JSch API)

java.lang.Object
- com.jcraft.jsch.Channel

All Implemented Interfaces:

Runnable

Direct Known Subclasses:

ChannelDirectTCPIP, ChannelExec, ChannelForwardedTCPIP, ChannelSftp, ChannelShell, ChannelSubsystem
```
public abstract class Channel
extends Object
implements Runnable
```
The abstract base class for the different types of channel which may be associated with a Session.
It should be considered an implementation detail that Channel implements Runnable – external code never has to invoke the run() method.

See Also:

Session.openChannel(java.lang.String)

Field Summary

Fields
Modifier and Type Field and Description

protected byte[] type

Fields
Modifier and Type	Field and Description
`protected byte[]`	`type`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`connect()` Opens the channel without any timeout.
`void`	`connect(int connectTimeout)` Opens the channel.
`void`	`disconnect()` disconnects this channel.
`protected com.jcraft.jsch.Packet`	`genChannelOpenPacket()`
`int`	`getExitStatus()` retrieves the exit status of the remote command corresponding to this channel.
`InputStream`	`getExtInputStream()` Gets an InputStream for extended data of this channel.
`int`	`getId()` returns the session-specific identifier of the channel.
`InputStream`	`getInputStream()` Gets an InputStream for this channel.
`OutputStream`	`getOutputStream()` Gets an OutputStream for this channel.
`Session`	`getSession()` Retrieves the session to which this channel belongs.
`boolean`	`isClosed()` returns true if this channel is already closed (or another thread is in progress of closing the channel).
`boolean`	`isConnected()` returns true if this channel is currently connected (which also means that the session is still connected).
`boolean`	`isEOF()` Checks if we have already read all the data, i.e. whether the remote side sent an end-of-file notification for this channel.
`void`	`run()` not to be called externally.
`protected void`	`sendChannelOpen()`
`protected void`	`sendOpenConfirmation()` sends a message confirming the opening of the channel.
`protected void`	`sendOpenFailure(int reasoncode)` sends a message indicating the failure of a channel-opening to the remote side.
`void`	`sendSignal(String signal)` sends a signal to the process at the other side.
`void`	`setExtOutputStream(OutputStream out)` Sets the OutputStream for extended data for this channel.
`void`	`setExtOutputStream(OutputStream out, boolean dontclose)` Sets the OutputStream for extended data for this channel.
`void`	`setInputStream(InputStream in)` Sets the InputStream for this channel.
`void`	`setInputStream(InputStream in, boolean dontclose)` Sets the InputStream for this channel.
`void`	`setOutputStream(OutputStream out)` Sets the OutputStream for this channel.
`void`	`setOutputStream(OutputStream out, boolean dontclose)` Sets the OutputStream for this channel.
`void`	`setXForwarding(boolean foo)` Enables or disables X forwarding for this channel.
`void`	`start()` Not to be called externally.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - type
```
protected byte[] type
```
- Method Detail
  - connect
```
public void connect()
             throws JSchException
```
    Opens the channel without any timeout. This is equivalent to connect(0) if not overridden in subclasses.
    
    Throws:
    
    JSchException
  - connect
```
public void connect(int connectTimeout)
             throws JSchException
```
    Opens the channel. This sends a SSH_MSH_CHANNEL_OPEN message and waits until the response is received. Warning: Some subclasses override connect() instead of this method, so calling this method with timeout parameter may then invoke the wrong method.
    
    Parameters:
    
    connectTimeout - the maximum time to wait for the channel to be established, in milliseconds. If 0, we wait as long as needed (but at most 1000 times 50 milliseconds each).
    
    Throws:
    
    JSchException - if a timeout occured, or some other connection problem.
  - setXForwarding
```
public void setXForwarding(boolean foo)
```
    Enables or disables X forwarding for this channel. This method does nothing here, but is implemented in subclasses for some types of channel (ChannelShell, ChannelSftp, ChannelExec, ChannelSubsystem).
  - start
```
public void start()
           throws JSchException
```
    Not to be called externally. This method is called by connect(int) when the connection is established. This implementation here does nothing, but it is overridden in some subclasses.
    
    Throws:
    
    JSchException
  - isEOF
```
public boolean isEOF()
```
    Checks if we have already read all the data, i.e. whether the remote side sent an end-of-file notification for this channel.
  - setInputStream
```
public void setInputStream(InputStream in)
```
    Sets the InputStream for this channel. The channel will then read from this stream and forward the data to the remote side. The stream will be closed on disconnect(com.jcraft.jsch.Session). This method should be called before connect().
  - setInputStream
```
public void setInputStream(InputStream in,
                           boolean dontclose)
```
    Sets the InputStream for this channel. The channel will then read from this stream and forward the data in SSH_MSG_CHANNEL_DATA to the remote side. This method should be called before connect().
    
    Parameters:
    
    dontclose - if true, we do not close the stream after usage.
  - setOutputStream
```
public void setOutputStream(OutputStream out)
```
    Sets the OutputStream for this channel. All data arriving in SSH_MSG_CHANNEL_DATA messages from the remote side will be written to this OutputStream. This method should be called before connect(). The stream will be closed on disconnect(com.jcraft.jsch.Session).
    
    See Also:
    
    getInputStream()
  - setOutputStream
```
public void setOutputStream(OutputStream out,
                            boolean dontclose)
```
    Sets the OutputStream for this channel. All data arriving in SSH_MSG_CHANNEL_DATA messages from the remote side will be written to this OutputStream. This method should be called before connect().
    
    Parameters:
    
    dontclose - if true, we do not close the stream on disconnect(com.jcraft.jsch.Session).
    
    See Also:
    
    getInputStream()
  - setExtOutputStream
```
public void setExtOutputStream(OutputStream out)
```
    Sets the OutputStream for extended data for this channel. All data arriving in SSH_MSG_CHANNEL_EXTENDED_DATA messages from the remote side will be written to this OutputStream.
    Note: This implementation does not differentiate between different 'data_type_code' values, as RFC 4254 only defines one type, namely SSH_EXTENDED_DATA_STDERR.
    This method should be called before connect(). The stream will be closed on disconnect(com.jcraft.jsch.Session).
    
    See Also:
    
    getExtInputStream()
  - setExtOutputStream
```
public void setExtOutputStream(OutputStream out,
                               boolean dontclose)
```
    Sets the OutputStream for extended data for this channel. All data arriving in SSH_MSG_CHANNEL_EXTENDED_DATA messages from the remote side will be written to this OutputStream.
    Note: This implementation does not differentiate between different 'data_type_code' values, as RFC 4254 only defines one type, namely SSH_EXTENDED_DATA_STDERR.
    This method should be called before connect().
    
    Parameters:
    
    dontclose - if true, we do not close the stream on disconnect(com.jcraft.jsch.Session).
    
    See Also:
    
    getExtInputStream()
  - getInputStream
```
public InputStream getInputStream()
                           throws IOException
```
    Gets an InputStream for this channel. All data arriving in SSH_MSG_CHANNEL_DATA messages from the remote side can be read from this stream. This method is a polling alternative to setOutputStream(java.io.OutputStream). It should be called before connect().
    
    Throws:
    
    IOException
  - getExtInputStream
```
public InputStream getExtInputStream()
                              throws IOException
```
    Gets an InputStream for extended data of this channel. All data arriving in SSH_MSG_CHANNEL_EXTENDED_DATA messages from the remote side can be read from this stream. This method is a polling alternative to setExtOutputStream(java.io.OutputStream). It should be called before connect().
    
    Throws:
    
    IOException
  - getOutputStream
```
public OutputStream getOutputStream()
                             throws IOException
```
    Gets an OutputStream for this channel. All data written to this stream will be sent in SSH_MSG_CHANNEL_DATA messages to the remote side. This method is an alternative to setInputStream(java.io.InputStream). It should be called before connect().
    
    Throws:
    
    IOException
  - run
```
public void run()
```
    not to be called externally. This will be overridden by subclasses which need to do special processing of channel data.
    
    Specified by:
    
    run in interface Runnable
  - isClosed
```
public boolean isClosed()
```
    returns true if this channel is already closed (or another thread is in progress of closing the channel).
  - disconnect
```
public void disconnect()
```
    disconnects this channel.
  - isConnected
```
public boolean isConnected()
```
    returns true if this channel is currently connected (which also means that the session is still connected).
  - sendSignal
```
public void sendSignal(String signal)
                throws Exception
```
    sends a signal to the process at the other side. This is only useful for interactive channels.
    
    Parameters:
    
    signal - the signal name, without the "SIG" prefix.
    
    Throws:
    
    Exception
    
    See Also:
    
    RFC 4254, Section 6.9. Signals
  - getExitStatus
```
public int getExitStatus()
```
    retrieves the exit status of the remote command corresponding to this channel. The exit status is only available for certain types of channels, and only after the channel was closed (more exactly, just before the channel is closed).
    
    Returns:
    
    the exitstatus returned by the remote command, or -1, if the command not yet terminated (or this channel type has no command).
    
    See Also:
    
    RFC 4254, Section 6.10 Returning Exit Status
  - getSession
```
public Session getSession()
                   throws JSchException
```
    Retrieves the session to which this channel belongs. This is mainly used internally.
    
    Throws:
    
    JSchException - if there is no such session.
  - getId
```
public int getId()
```
    returns the session-specific identifier of the channel.
  - sendOpenConfirmation
```
protected void sendOpenConfirmation()
                             throws Exception
```
    sends a message confirming the opening of the channel.
    
    Throws:
    
    Exception
  - sendOpenFailure
```
protected void sendOpenFailure(int reasoncode)
```
    sends a message indicating the failure of a channel-opening to the remote side.
  - genChannelOpenPacket
```
protected com.jcraft.jsch.Packet genChannelOpenPacket()
```
  - sendChannelOpen
```
protected void sendChannelOpen()
                        throws Exception
```
    Throws:
    
    Exception

Class Channel

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

type

Method Detail

connect

connect

setXForwarding

start

isEOF

setInputStream

setInputStream

setOutputStream

setOutputStream

setExtOutputStream

setExtOutputStream

getInputStream

getExtInputStream

getOutputStream

run

isClosed

disconnect

isConnected

sendSignal

getExitStatus

getSession

getId

sendOpenConfirmation

sendOpenFailure

genChannelOpenPacket

sendChannelOpen