Package org.apache.commons.net.telnet
Class TelnetClient
- java.lang.Object
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- org.apache.commons.net.SocketClient
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- org.apache.commons.net.telnet.TelnetClient
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- Direct Known Subclasses:
FTP
public class TelnetClient extends SocketClient
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 thegetInputStream()
andgetOutputStream()
methods. When you finish using the streams, you must calldisconnect
rather than simply closing the streams.- Author:
- Daniel F. Savarese, Bruno D'Avanzo
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Field Summary
Fields Modifier and Type Field Description protected boolean
readerThread
protected static int
TERMINAL_TYPE
Terminal type optionprotected static int
TERMINAL_TYPE_IS
Is (for subnegotiation)protected static int
TERMINAL_TYPE_SEND
Send (for subnegotiation)-
Fields inherited from class org.apache.commons.net.SocketClient
_defaultPort_, _input_, _isConnected_, _output_, _socket_, _socketFactory_, _timeout_, NETASCII_EOL
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Constructor Summary
Constructors Constructor Description TelnetClient()
Default TelnetClient constructor.TelnetClient(java.lang.String termtype)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description protected void
_connectAction_()
Handles special connection requirements.void
addOptionHandler(TelnetOptionHandler opthand)
Registers a new TelnetOptionHandler for this telnet client to use.void
deleteOptionHandler(int optcode)
Unregisters a TelnetOptionHandler.void
disconnect()
Disconnects the telnet session, closing the input and output streams as well as the socket.java.io.InputStream
getInputStream()
Returns the telnet connection input stream.boolean
getLocalOptionState(int option)
Returns the state of the option on the local side.java.io.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
registerNotifHandler(TelnetNotificationHandler notifhand)
Registers a notification handler to which will be sent notifications of received telnet option negotiation commands.void
registerSpyStream(java.io.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.void
unregisterNotifHandler()
Unregisters the current notification handler.-
Methods inherited from class org.apache.commons.net.SocketClient
connect, connect, connect, connect, connect, connect, getDefaultPort, getDefaultTimeout, getLocalAddress, getLocalPort, getRemoteAddress, getRemotePort, getSoLinger, getSoTimeout, getTcpNoDelay, isConnected, setDefaultPort, setDefaultTimeout, setSocketFactory, setSoLinger, setSoTimeout, setTcpNoDelay, verifyRemote
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Field Detail
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readerThread
protected boolean readerThread
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TERMINAL_TYPE
protected static final int TERMINAL_TYPE
Terminal type option- See Also:
- Constant Field Values
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TERMINAL_TYPE_SEND
protected static final int TERMINAL_TYPE_SEND
Send (for subnegotiation)- See Also:
- Constant Field Values
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TERMINAL_TYPE_IS
protected static final int TERMINAL_TYPE_IS
Is (for subnegotiation)- See Also:
- Constant Field Values
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Method Detail
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_connectAction_
protected void _connectAction_() throws java.io.IOException
Handles special connection requirements.- Throws:
java.io.IOException
- If an error occurs during connection setup.
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disconnect
public void disconnect() throws java.io.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.- Overrides:
disconnect
in classSocketClient
- Throws:
java.io.IOException
- If there is an error closing the socket.
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getOutputStream
public java.io.OutputStream getOutputStream()
Returns the telnet connection output stream. You should not close the stream when you finish with it. Rather, you should calldisconnect
.- Returns:
- The telnet connection output stream.
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getInputStream
public java.io.InputStream getInputStream()
Returns the telnet connection input stream. You should not close the stream when you finish with it. Rather, you should calldisconnect
.- Returns:
- The telnet connection input stream.
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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.
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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.
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sendAYT
public boolean sendAYT(long timeout) throws java.io.IOException, java.lang.IllegalArgumentException, java.lang.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
- Throws:
java.lang.InterruptedException
java.lang.IllegalArgumentException
java.io.IOException
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addOptionHandler
public void addOptionHandler(TelnetOptionHandler opthand) throws InvalidTelnetOptionException
Registers a new TelnetOptionHandler for this telnet client to use.- Parameters:
opthand
- - option handler to be registered.- Throws:
InvalidTelnetOptionException
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deleteOptionHandler
public void deleteOptionHandler(int optcode) throws InvalidTelnetOptionException
Unregisters a TelnetOptionHandler.- Parameters:
optcode
- - Code of the option to be unregistered.- Throws:
InvalidTelnetOptionException
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registerSpyStream
public void registerSpyStream(java.io.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.
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stopSpyStream
public void stopSpyStream()
Stops spying this TelnetClient.
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registerNotifHandler
public 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
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unregisterNotifHandler
public void unregisterNotifHandler()
Unregisters the current notification handler.
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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
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getReaderThread
public boolean getReaderThread()
Gets the status of the reader thread.- Returns:
- true if the reader thread is on, false otherwise
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