Ssh2Channel (Maverick Legacy - Client Assembly 1.7.58 API)

java.lang.Object
- com.maverick.ssh.message.SshAbstractChannel
- - com.maverick.ssh2.Ssh2Channel

All Implemented Interfaces:

SshChannel, SshIO

Direct Known Subclasses:

AgentSocketForwardingChannel, Ssh2Session
```
public class Ssh2Channel
extends SshAbstractChannel
```
All terminal sessions, forwarded connections, etc are channels and this class implements the base SSH2 channel. Either side may open a channel and multiple channels are multiplexed into a single SSH connection. SSH2 channels are flow controlled, no data may be sent to a channel until a message is received to indicate that window space is available.

To open a channel, first create an instance of the channel as follows:
```
 Ssh2Channel channel = new Ssh2Channel("session", 32768, 32768);
 
```
The second value passed into the constructor is the initial window space and also the maximum amount of window space that will be available to the other side. The channel manages the window space automatically by increasing the amount available once the data has been read from the channels InputStream and only when the current value falls below half of the maximum.

After the channel has been created the channel is opened through a call to openChannel(Ssh2Channel channel). Once the channel is open you can use the IO streams to send and receive data.
Author:

Lee David Painter

Field Summary

Fields
Modifier and Type Field and Description

static String SESSION_CHANNEL
- Fields inherited from class com.maverick.ssh.message.SshAbstractChannel
  CHANNEL_CLOSED, CHANNEL_OPEN, CHANNEL_UNINITIALIZED, channelid, manager, ms, state

Fields
Modifier and Type	Field and Description
`static String`	`SESSION_CHANNEL`

Constructor Summary

Constructors
Constructor and Description

Ssh2Channel(String name, int windowsize, int packetsize)

Constructors
Constructor and Description
`Ssh2Channel(String name, int windowsize, int packetsize)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addChannelEventListener(ChannelEventListener listener)` Provides an event listening mechanism.
`protected void`	`channelEOF()` Called when the remote side data stream is EOF, by default this method does nothing
`protected void`	`channelRequest(String requesttype, boolean wantreply, byte[] requestdata)` Called when a channel request is received, by default this method sends a failure message if the remote side requests a reply.
`protected void`	`checkCloseStatus(boolean remoteClosed)`
`void`	`close()` Closes the channel.
`protected byte[]`	`create()` Called after the channel has been created by the	`protected com.maverick.ssh2.Ssh2Channel.ChannelInputStream`	`createExtendedDataStream()` Currently reserved.
`boolean`	`equals(Object obj)` This channel is equal to another channel if the channel id's are equal.
`protected void`	`free()`
`SshClient`	`getClient()` The SshClient that this channel belongs to
`com.maverick.ssh2.ConnectionProtocol`	`getConnection()`
`InputStream`	`getInputStream()` Get an InputStream to read incoming channel data.
`int`	`getMaximumLocalPacketLength()` The maximum packet length supported by this channel.
`long`	`getMaximumLocalWindowSize()`
`int`	`getMaximumRemotePacketLength()` The maximum packet length supported by this channel.
`long`	`getMaximumRemoteWindowSize()`
`protected SshMessageStore`	`getMessageStore()`
`String`	`getName()` Get the name of the channel.
`OutputStream`	`getOutputStream()` Get an OutputStream to write outgoing channel data.
`long`	`getRemoteWindow()`
`protected MessageObserver`	`getStickyMessageIds()`
`void`	`idle()`
`boolean`	`isSendKeepAliveOnIdle()`
`protected void`	`open(int remoteid, long remotewindow, int remotepacket)` Called once an SSH_MSG_CHANNEL_OPEN_CONFIRMATION has been sent.
`protected void`	`open(int remoteid, long remotewindow, int remotepacket, byte[] responsedata)` Once a SSH_MSG_CHANNEL_OPEN_CONFIRMATION message is received the framework calls this method to complete the channel open operation.
`protected boolean`	`processChannelMessage(SshChannelMessage msg)` Processes channel request messages by passing the request through to channelRequest() .
`protected void`	`processExtendedData(int typecode, int length, SshChannelMessage msg)` Called when extended data arrives.
`protected void`	`processStandardData(int length, SshChannelMessage msg)` Called when channel data arrives, by default this method makes the data available in the channels InputStream.
`void`	`removeChannelEventListener(ChannelEventListener listener)` Provides an event listening mechanism.
`boolean`	`sendRequest(String requesttype, boolean wantreply, byte[] requestdata)` Sends a channel request.
`boolean`	`sendRequest(String requesttype, boolean wantreply, byte[] requestdata, boolean isActivity)` Sends a channel request.
`void`	`setAutoConsumeInput(boolean autoConsumeInput)` Automatically consume input data
`void`	`setSendKeepAliveOnIdle(boolean sendKeepAliveOnIdle)`

Methods inherited from class com.maverick.ssh.message.SshAbstractChannel
getChannelId, getMessageRouter, init, isClosed, waitForOpen

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

- Field Detail
  - SESSION_CHANNEL
```
public static final String SESSION_CHANNEL
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - Ssh2Channel
```
public Ssh2Channel(String name,
                   int windowsize,
                   int packetsize)
```
- Method Detail
  - getClient
```
public SshClient getClient()
```
    Description copied from interface: SshChannel
    
    The SshClient that this channel belongs to
    
    Returns:
  - getConnection
```
public com.maverick.ssh2.ConnectionProtocol getConnection()
```
  - getStickyMessageIds
```
protected MessageObserver getStickyMessageIds()
```
    Specified by:
    
    getStickyMessageIds in class SshAbstractChannel
  - setAutoConsumeInput
```
public void setAutoConsumeInput(boolean autoConsumeInput)
```
    Description copied from interface: SshChannel
    
    Automatically consume input data
    
    Parameters:
    
    autoConsumeInput - boolean
  - getMessageStore
```
protected SshMessageStore getMessageStore()
                                   throws SshException
```
    Overrides:
    
    getMessageStore in class SshAbstractChannel
    
    Throws:
    
    SshException
  - getName
```
public String getName()
```
    Get the name of the channel.
    
    Returns:
    
    the name of the channel.
  - getInputStream
```
public InputStream getInputStream()
```
    Description copied from interface: SshIO
    
    Get an InputStream to read incoming channel data.
    
    Returns:
    
    the channels InputStream
  - getOutputStream
```
public OutputStream getOutputStream()
```
    Description copied from interface: SshIO
    
    Get an OutputStream to write outgoing channel data.
    
    Returns:
    
    the channels OutputStream
  - addChannelEventListener
```
public void addChannelEventListener(ChannelEventListener listener)
```
    Description copied from interface: SshChannel
    
    Provides an event listening mechanism.
  - removeChannelEventListener
```
public void removeChannelEventListener(ChannelEventListener listener)
```
    Description copied from interface: SshChannel
    
    Provides an event listening mechanism.
  - isSendKeepAliveOnIdle
```
public boolean isSendKeepAliveOnIdle()
```
  - setSendKeepAliveOnIdle
```
public void setSendKeepAliveOnIdle(boolean sendKeepAliveOnIdle)
```
  - idle
```
public void idle()
```
    Overrides:
    
    idle in class SshAbstractChannel
  - create
```
protected byte[] create()
```
    Called after the channel has been created by the Returns:
    data that should be returned in the SSH_MSG_CHANNEL_OPEN_CONFIRMATION message
    
    Throws:
    
    IOException
  - open
```
protected void open(int remoteid,
                    long remotewindow,
                    int remotepacket)
             throws IOException
```
    Called once an SSH_MSG_CHANNEL_OPEN_CONFIRMATION has been sent.
    
    Parameters:
    
    remoteid -
    
    remotewindow -
    
    remotepacket -
    
    Throws:
    
    IOException
  - getMaximumRemotePacketLength
```
public int getMaximumRemotePacketLength()
```
    Description copied from interface: SshChannel
    
    The maximum packet length supported by this channel.
    
    Returns:
  - getMaximumLocalPacketLength
```
public int getMaximumLocalPacketLength()
```
    Description copied from interface: SshChannel
    
    The maximum packet length supported by this channel.
    
    Returns:
  - getMaximumLocalWindowSize
```
public long getMaximumLocalWindowSize()
```
  - getMaximumRemoteWindowSize
```
public long getMaximumRemoteWindowSize()
```
  - open
```
protected void open(int remoteid,
                    long remotewindow,
                    int remotepacket,
                    byte[] responsedata)
             throws IOException
```
    Once a SSH_MSG_CHANNEL_OPEN_CONFIRMATION message is received the framework calls this method to complete the channel open operation.
    
    Parameters:
    
    remoteid - the senders id
    
    remotewindow - the initial window space available for sending data
    
    remotepacket - the maximum packet size available for sending data
    
    responsedata - the data returned from the remote side in the SSH_MSG_CHANNEL_OPEN_CONFIRMATION message
    
    Throws:
    
    IOException
  - processChannelMessage
```
protected boolean processChannelMessage(SshChannelMessage msg)
                                 throws SshException
```
    Processes channel request messages by passing the request through to channelRequest() .
    
    Specified by:
    
    processChannelMessage in class SshAbstractChannel
    
    Throws:
    
    SshException
  - processStandardData
```
protected void processStandardData(int length,
                                   SshChannelMessage msg)
                            throws SshException
```
    Called when channel data arrives, by default this method makes the data available in the channels InputStream. Override this method to change this behaviour.
    
    Parameters:
    
    buf -
    
    offset -
    
    len -
    
    Throws:
    
    IOException
    
    SshException
  - processExtendedData
```
protected void processExtendedData(int typecode,
                                   int length,
                                   SshChannelMessage msg)
                            throws SshException
```
    Called when extended data arrives. This method fires the com.maverick.ssh.ChannelEventListener#extendedDataReceived(com.maverick.ssh.Channel, byte[], int, int, int) event so to maintain code compatibility always call the super method in any overidden method.
    
    Parameters:
    
    typecode - the type of extended data
    
    buf - the data buffer
    
    offset - the offset
    
    len - the length
    
    Throws:
    
    SshException
    
    IOException
  - createExtendedDataStream
```
protected com.maverick.ssh2.Ssh2Channel.ChannelInputStream createExtendedDataStream()
```
    Currently reserved.
    
    Returns:
    
    ChannelInputStream
  - sendRequest
```
public boolean sendRequest(String requesttype,
                           boolean wantreply,
                           byte[] requestdata)
                    throws SshException
```
    Sends a channel request. Many channels have extensions that are specific to that particular channel type, an example of which is requesting a pseudo terminal from an interactive session.
    
    Parameters:
    
    requesttype - the name of the request, for example "pty-req"
    
    wantreply - specifies whether the remote side should send a success/failure message
    
    requestdata - the request data
    
    Returns:
    
    true if the request succeeded and wantreply=true, otherwise false
    
    Throws:
    
    IOException
    
    SshException
  - sendRequest
```
public boolean sendRequest(String requesttype,
                           boolean wantreply,
                           byte[] requestdata,
                           boolean isActivity)
                    throws SshException
```
    Sends a channel request. Many channels have extensions that are specific to that particular channel type, an example of which is requesting a pseudo terminal from an interactive session.
    
    Parameters:
    
    requesttype - the name of the request, for example "pty-req"
    
    wantreply - specifies whether the remote side should send a success/failure message
    
    requestdata - the request data
    
    isActivity -
    
    Returns:
    
    true if the request succeeded and wantreply=true, otherwise false
    
    Throws:
    
    IOException
    
    SshException
  - getRemoteWindow
```
public long getRemoteWindow()
```
  - close
```
public void close()
```
    Closes the channel. No data may be sent or receieved after this method completes.
  - checkCloseStatus
```
protected void checkCloseStatus(boolean remoteClosed)
```
  - free
```
protected void free()
```
  - equals
```
public boolean equals(Object obj)
```
    This channel is equal to another channel if the channel id's are equal. Please note that channel numbers may be reused so this method should only be called on open channels.
    
    Overrides:
    
    equals in class Object
  - channelRequest
```
protected void channelRequest(String requesttype,
                              boolean wantreply,
                              byte[] requestdata)
                       throws SshException
```
    Called when a channel request is received, by default this method sends a failure message if the remote side requests a reply. Overidden methods should ALWAYS call this superclass method.
    
    Parameters:
    
    requesttype - the name of the request
    
    wantreply - specifies whether the remote side requires a success/failure message
    
    requestdata - the request data
    
    Throws:
    
    IOException
    
    SshException
  - channelEOF
```
protected void channelEOF()
```
    Called when the remote side data stream is EOF, by default this method does nothing
    
    Throws:
    
    IOException

Class Ssh2Channel

Field Summary

Fields inherited from class com.maverick.ssh.message.SshAbstractChannel

Constructor Summary

Method Summary

Methods inherited from class com.maverick.ssh.message.SshAbstractChannel

Methods inherited from class java.lang.Object

Field Detail

SESSION_CHANNEL

Constructor Detail

Ssh2Channel

Method Detail

getClient

getConnection

getStickyMessageIds

setAutoConsumeInput

getMessageStore

getName

getInputStream

getOutputStream

addChannelEventListener

removeChannelEventListener

isSendKeepAliveOnIdle

setSendKeepAliveOnIdle

idle

create

open

getMaximumRemotePacketLength

getMaximumLocalPacketLength

getMaximumLocalWindowSize

getMaximumRemoteWindowSize

open

processChannelMessage

processStandardData

processExtendedData

createExtendedDataStream

sendRequest

sendRequest

getRemoteWindow

close

checkCloseStatus

free

equals

channelRequest

channelEOF