org.apache.commons.net.telnet

Class TelnetClient


public class TelnetClient
extends Telnet

The TelnetClient class implements the simple network virtual terminal (NVT) for the Telnet protocol according to RFC 854. It does not implement any of the extra Telnet options because it is meant to be used within a Java program providing automated access to Telnet accessible resources.

The class can be used by first connecting to a server using the SocketClient connect method. Then an InputStream and OutputStream for sending and receiving data over the Telnet connection can be obtained by using the getInputStream() and getOutputStream() methods. When you finish using the streams, you must call disconnect rather than simply closing the streams.

Field Summary

protected boolean
readerThread

Constructor Summary

TelnetClient()
Default TelnetClient constructor.
TelnetClient(String termtype)

Method Summary

InputStream
getInputStream()
Returns the telnet connection input stream.
boolean
getLocalOptionState(int option)
Returns the state of the option on the local side.
OutputStream
getOutputStream()
Returns the telnet connection output stream.
boolean
getReaderThread()
Gets the status of the reader thread.
boolean
getRemoteOptionState(int option)
Returns the state of the option on the remote side.
void
registerSpyStream(OutputStream spystream)
Registers an OutputStream for spying what's going on in the TelnetClient session.
boolean
sendAYT(long timeout)
Sends an Are You There sequence and waits for the result.
void
setReaderThread(boolean flag)
Sets the status of the reader thread.
void
stopSpyStream()
Stops spying this TelnetClient.
protected @Override
void _connectAction_()
Handles special connection requirements.
@Override
void addOptionHandler(TelnetOptionHandler opthand)
Registers a new TelnetOptionHandler for this telnet client to use.
@Override
void deleteOptionHandler(int optcode)
Unregisters a TelnetOptionHandler.
@Override
void disconnect()
Disconnects the telnet session, closing the input and output streams as well as the socket.
@Override
void registerNotifHandler(TelnetNotificationHandler notifhand)
Registers a notification handler to which will be sent notifications of received telnet option negotiation commands.
@Override
void unregisterNotifHandler()
Unregisters the current notification handler.

Field Details

readerThread

protected boolean readerThread

Constructor Details

TelnetClient

public TelnetClient()
Default TelnetClient constructor.

TelnetClient

public TelnetClient(String termtype)

Method Details

getInputStream

public InputStream getInputStream()
Returns the telnet connection input stream. You should not close the stream when you finish with it. Rather, you should call disconnect.

Returns:
The telnet connection input stream.

getLocalOptionState

public boolean getLocalOptionState(int option)
Returns the state of the option on the local side.

Parameters:
option - - Option to be checked.

Returns:
The state of the option on the local side.

getOutputStream

public OutputStream getOutputStream()
Returns the telnet connection output stream. You should not close the stream when you finish with it. Rather, you should call disconnect.

Returns:
The telnet connection output stream.

getReaderThread

public boolean getReaderThread()
Gets the status of the reader thread.

Returns:
true if the reader thread is on, false otherwise

getRemoteOptionState

public boolean getRemoteOptionState(int option)
Returns the state of the option on the remote side.

Parameters:
option - - Option to be checked.

Returns:
The state of the option on the remote side.

registerSpyStream

public void registerSpyStream(OutputStream spystream)
Registers an OutputStream for spying what's going on in the TelnetClient session.

Parameters:
spystream - - OutputStream on which session activity will be echoed.

sendAYT

public boolean sendAYT(long timeout)
            throws IOException,
                   IllegalArgumentException,
                   InterruptedException
Sends an Are You There sequence and waits for the result.

Parameters:
timeout - - Time to wait for a response (millis.)

Returns:
true if AYT received a response, false otherwise

setReaderThread

public void setReaderThread(boolean flag)
Sets the status of the reader thread. The reader thread status will apply to all subsequent connections

Parameters:
flag - - true switches the reader thread on, false switches it off

stopSpyStream

public void stopSpyStream()
Stops spying this TelnetClient.


void _connectAction_

protected @Override void _connectAction_()
            throws IOException
Handles special connection requirements.


void addOptionHandler

public @Override void addOptionHandler(TelnetOptionHandler opthand)
            throws InvalidTelnetOptionException
Registers a new TelnetOptionHandler for this telnet client to use.

Parameters:
opthand - - option handler to be registered.


void deleteOptionHandler

public @Override void deleteOptionHandler(int optcode)
            throws InvalidTelnetOptionException
Unregisters a TelnetOptionHandler.

Parameters:
optcode - - Code of the option to be unregistered.


void disconnect

public @Override void disconnect()
            throws IOException
Disconnects the telnet session, closing the input and output streams as well as the socket. If you have references to the input and output streams of the telnet connection, you should not close them yourself, but rather call disconnect to properly close the connection.

void registerNotifHandler

public @Override void registerNotifHandler(TelnetNotificationHandler notifhand)
Registers a notification handler to which will be sent notifications of received telnet option negotiation commands.

Parameters:
notifhand - - TelnetNotificationHandler to be registered

void unregisterNotifHandler

public @Override void unregisterNotifHandler()
Unregisters the current notification handler.