org.apache.commons.net.telnet.TelnetOptionHandler Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.net.telnet;
/***
* The TelnetOptionHandler class is the base class to be used
* for implementing handlers for telnet options.
*
* TelnetOptionHandler implements basic option handling
* functionality and defines abstract methods that must be
* implemented to define subnegotiation behaviour.
***/
public abstract class TelnetOptionHandler
{
/***
* Option code
***/
private int optionCode = -1;
/***
* true if the option should be activated on the local side
***/
private boolean initialLocal = false;
/***
* true if the option should be activated on the remote side
***/
private boolean initialRemote = false;
/***
* true if the option should be accepted on the local side
***/
private boolean acceptLocal = false;
/***
* true if the option should be accepted on the remote side
***/
private boolean acceptRemote = false;
/***
* true if the option is active on the local side
***/
private boolean doFlag = false;
/***
* true if the option is active on the remote side
***/
private boolean willFlag = false;
/***
* Constructor for the TelnetOptionHandler. Allows defining desired
* initial setting for local/remote activation of this option and
* behaviour in case a local/remote activation request for this
* option is received.
*
* @param optcode - Option code.
* @param initlocal - if set to true, a WILL is sent upon connection.
* @param initremote - if set to true, a DO is sent upon connection.
* @param acceptlocal - if set to true, any DO request is accepted.
* @param acceptremote - if set to true, any WILL request is accepted.
***/
public TelnetOptionHandler(int optcode,
boolean initlocal,
boolean initremote,
boolean acceptlocal,
boolean acceptremote)
{
optionCode = optcode;
initialLocal = initlocal;
initialRemote = initremote;
acceptLocal = acceptlocal;
acceptRemote = acceptremote;
}
/***
* Returns the option code for this option.
*
* @return Option code.
***/
public int getOptionCode()
{
return (optionCode);
}
/***
* Returns a boolean indicating whether to accept a DO
* request coming from the other end.
*
* @return true if a DO request shall be accepted.
***/
public boolean getAcceptLocal()
{
return (acceptLocal);
}
/***
* Returns a boolean indicating whether to accept a WILL
* request coming from the other end.
*
* @return true if a WILL request shall be accepted.
***/
public boolean getAcceptRemote()
{
return (acceptRemote);
}
/***
* Set behaviour of the option for DO requests coming from
* the other end.
*
* @param accept - if true, subsequent DO requests will be accepted.
***/
public void setAcceptLocal(boolean accept)
{
acceptLocal = accept;
}
/***
* Set behaviour of the option for WILL requests coming from
* the other end.
*
* @param accept - if true, subsequent WILL requests will be accepted.
***/
public void setAcceptRemote(boolean accept)
{
acceptRemote = accept;
}
/***
* Returns a boolean indicating whether to send a WILL request
* to the other end upon connection.
*
* @return true if a WILL request shall be sent upon connection.
***/
public boolean getInitLocal()
{
return (initialLocal);
}
/***
* Returns a boolean indicating whether to send a DO request
* to the other end upon connection.
*
* @return true if a DO request shall be sent upon connection.
***/
public boolean getInitRemote()
{
return (initialRemote);
}
/***
* Tells this option whether to send a WILL request upon connection.
*
* @param init - if true, a WILL request will be sent upon subsequent
* connections.
***/
public void setInitLocal(boolean init)
{
initialLocal = init;
}
/***
* Tells this option whether to send a DO request upon connection.
*
* @param init - if true, a DO request will be sent upon subsequent
* connections.
***/
public void setInitRemote(boolean init)
{
initialRemote = init;
}
/***
* Method called upon reception of a subnegotiation for this option
* coming from the other end.
*
* This implementation returns null, and
* must be overridden by the actual TelnetOptionHandler to specify
* which response must be sent for the subnegotiation request.
*
* @param suboptionData - the sequence received, without IAC SB & IAC SE
* @param suboptionLength - the length of data in suboption_data
*
* @return response to be sent to the subnegotiation sequence. TelnetClient
* will add IAC SB & IAC SE. null means no response
***/
public int[] answerSubnegotiation(int suboptionData[], int suboptionLength) {
return null;
}
/***
* This method is invoked whenever this option is acknowledged active on
* the local end (TelnetClient sent a WILL, remote side sent a DO).
* The method is used to specify a subnegotiation sequence that will be
* sent by TelnetClient when the option is activated.
*
* This implementation returns null, and must be overriden by
* the actual TelnetOptionHandler to specify
* which response must be sent for the subnegotiation request.
* @return subnegotiation sequence to be sent by TelnetClient. TelnetClient
* will add IAC SB & IAC SE. null means no subnegotiation.
***/
public int[] startSubnegotiationLocal() {
return null;
}
/***
* This method is invoked whenever this option is acknowledged active on
* the remote end (TelnetClient sent a DO, remote side sent a WILL).
* The method is used to specify a subnegotiation sequence that will be
* sent by TelnetClient when the option is activated.
*
* This implementation returns null, and must be overriden by
* the actual TelnetOptionHandler to specify
* which response must be sent for the subnegotiation request.
* @return subnegotiation sequence to be sent by TelnetClient. TelnetClient
* will add IAC SB & IAC SE. null means no subnegotiation.
***/
public int[] startSubnegotiationRemote() {
return null;
}
/***
* Returns a boolean indicating whether a WILL request sent to the other
* side has been acknowledged.
*
* @return true if a WILL sent to the other side has been acknowledged.
***/
boolean getWill()
{
return willFlag;
}
/***
* Tells this option whether a WILL request sent to the other
* side has been acknowledged (invoked by TelnetClient).
*
* @param state - if true, a WILL request has been acknowledged.
***/
void setWill(boolean state)
{
willFlag = state;
}
/***
* Returns a boolean indicating whether a DO request sent to the other
* side has been acknowledged.
*
* @return true if a DO sent to the other side has been acknowledged.
***/
boolean getDo()
{
return doFlag;
}
/***
* Tells this option whether a DO request sent to the other
* side has been acknowledged (invoked by TelnetClient).
*
* @param state - if true, a DO request has been acknowledged.
***/
void setDo(boolean state)
{
doFlag = state;
}
}