/*
* 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 TelnetCommand class cannot be instantiated and only serves as a
* storehouse for telnet command constants.
* @author Daniel F. Savarese
* @see org.apache.commons.net.telnet.Telnet
* @see org.apache.commons.net.telnet.TelnetClient
*/
public final class TelnetCommand
{
/*** The maximum value a command code can have. This value is 255. ***/
public static final int MAX_COMMAND_VALUE = 255;
/*** Interpret As Command code. Value is 255 according to RFC 854. ***/
public static final int IAC = 255;
/*** Don't use option code. Value is 254 according to RFC 854. ***/
public static final int DONT = 254;
/*** Request to use option code. Value is 253 according to RFC 854. ***/
public static final int DO = 253;
/*** Refuse to use option code. Value is 252 according to RFC 854. ***/
public static final int WONT = 252;
/*** Agree to use option code. Value is 251 according to RFC 854. ***/
public static final int WILL = 251;
/*** Start subnegotiation code. Value is 250 according to RFC 854. ***/
public static final int SB = 250;
/*** Go Ahead code. Value is 249 according to RFC 854. ***/
public static final int GA = 249;
/*** Erase Line code. Value is 248 according to RFC 854. ***/
public static final int EL = 248;
/*** Erase Character code. Value is 247 according to RFC 854. ***/
public static final int EC = 247;
/*** Are You There code. Value is 246 according to RFC 854. ***/
public static final int AYT = 246;
/*** Abort Output code. Value is 245 according to RFC 854. ***/
public static final int AO = 245;
/*** Interrupt Process code. Value is 244 according to RFC 854. ***/
public static final int IP = 244;
/*** Break code. Value is 243 according to RFC 854. ***/
public static final int BREAK = 243;
/*** Data mark code. Value is 242 according to RFC 854. ***/
public static final int DM = 242;
/*** No Operation code. Value is 241 according to RFC 854. ***/
public static final int NOP = 241;
/*** End subnegotiation code. Value is 240 according to RFC 854. ***/
public static final int SE = 240;
/*** End of record code. Value is 239. ***/
public static final int EOR = 239;
/*** Abort code. Value is 238. ***/
public static final int ABORT = 238;
/*** Suspend process code. Value is 237. ***/
public static final int SUSP = 237;
/*** End of file code. Value is 236. ***/
public static final int EOF = 236;
/*** Synchronize code. Value is 242. ***/
public static final int SYNCH = 242;
/*** String representations of commands. ***/
private static final String __commandString[] = {
"IAC", "DONT", "DO", "WONT", "WILL", "SB", "GA", "EL", "EC", "AYT",
"AO", "IP", "BRK", "DMARK", "NOP", "SE", "EOR", "ABORT", "SUSP", "EOF"
};
private static final int __FIRST_COMMAND = IAC;
private static final int __LAST_COMMAND = EOF;
/***
* Returns the string representation of the telnet protocol command
* corresponding to the given command code.
* <p>
* @param code The command code of the telnet protocol command.
* @return The string representation of the telnet protocol command.
***/
public static final String getCommand(int code)
{
return __commandString[__FIRST_COMMAND - code];
}
/***
* Determines if a given command code is valid. Returns true if valid,
* false if not.
* <p>
* @param code The command code to test.
* @return True if the command code is valid, false if not.
**/
public static final boolean isValidCommand(int code)
{
return (code <= __FIRST_COMMAND && code >= __LAST_COMMAND);
}
// Cannot be instantiated
private TelnetCommand()
{ }
}