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Java > Open Source Codes > org > apache > commons > net > telnet > TelnetOptionHandler


1 /*
2  * Copyright 2003-2004 The Apache Software Foundation
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package org.apache.commons.net.telnet;
17
18 /***
19  * The TelnetOptionHandler class is the base class to be used
20  * for implementing handlers for telnet options.
21  * <p>
22  * TelnetOptionHandler implements basic option handling
23  * functionality and defines abstract methods that must be
24  * implemented to define subnegotiation behaviour.
25  * <p>
26  * @author Bruno D'Avanzo
27  ***/
28 public abstract class TelnetOptionHandler
29 {
30     /***
31      * Option code
32      ***/
33     private int optionCode = -1;
34
35     /***
36      * true if the option should be activated on the local side
37      ***/
38     private boolean initialLocal = false;
39
40     /***
41      * true if the option should be activated on the remote side
42      ***/
43     private boolean initialRemote = false;
44
45     /***
46      * true if the option should be accepted on the local side
47      ***/
48     private boolean acceptLocal = false;
49
50     /***
51      * true if the option should be accepted on the remote side
52      ***/
53     private boolean acceptRemote = false;
54
55     /***
56      * true if the option is active on the local side
57      ***/
58     private boolean doFlag = false;
59
60     /***
61      * true if the option is active on the remote side
62      ***/
63     private boolean willFlag = false;
64
65     /***
66      * Constructor for the TelnetOptionHandler. Allows defining desired
67      * initial setting for local/remote activation of this option and
68      * behaviour in case a local/remote activation request for this
69      * option is received.
70      * <p>
71      * @param optcode - Option code.
72      * @param initlocal - if set to true, a WILL is sent upon connection.
73      * @param initremote - if set to true, a DO is sent upon connection.
74      * @param acceptlocal - if set to true, any DO request is accepted.
75      * @param acceptremote - if set to true, any WILL request is accepted.
76      ***/
77     public TelnetOptionHandler(int optcode,
78                                 boolean initlocal,
79                                 boolean initremote,
80                                 boolean acceptlocal,
81                                 boolean acceptremote)
82     {
83         optionCode = optcode;
84         initialLocal = initlocal;
85         initialRemote = initremote;
86         acceptLocal = acceptlocal;
87         acceptRemote = acceptremote;
88     }
89
90
91     /***
92      * Returns the option code for this option.
93      * <p>
94      * @return Option code.
95      ***/
96     public int getOptionCode()
97     {
98         return (optionCode);
99     }
100
101     /***
102      * Returns a boolean indicating whether to accept a DO
103      * request coming from the other end.
104      * <p>
105      * @return true if a DO request shall be accepted.
106      ***/
107     public boolean getAcceptLocal()
108     {
109         return (acceptLocal);
110     }
111
112     /***
113      * Returns a boolean indicating whether to accept a WILL
114      * request coming from the other end.
115      * <p>
116      * @return true if a WILL request shall be accepted.
117      ***/
118     public boolean getAcceptRemote()
119     {
120         return (acceptRemote);
121     }
122
123     /***
124      * Set behaviour of the option for DO requests coming from
125      * the other end.
126      * <p>
127      * @param accept - if true, subsequent DO requests will be accepted.
128      ***/
129     public void setAcceptLocal(boolean accept)
130     {
131         acceptLocal = accept;
132     }
133
134     /***
135      * Set behaviour of the option for WILL requests coming from
136      * the other end.
137      * <p>
138      * @param accept - if true, subsequent WILL requests will be accepted.
139      ***/
140     public void setAcceptRemote(boolean accept)
141     {
142         acceptRemote = accept;
143     }
144
145     /***
146      * Returns a boolean indicating whether to send a WILL request
147      * to the other end upon connection.
148      * <p>
149      * @return true if a WILL request shall be sent upon connection.
150      ***/
151     public boolean getInitLocal()
152     {
153         return (initialLocal);
154     }
155
156     /***
157      * Returns a boolean indicating whether to send a DO request
158      * to the other end upon connection.
159      * <p>
160      * @return true if a DO request shall be sent upon connection.
161      ***/
162     public boolean getInitRemote()
163     {
164         return (initialRemote);
165     }
166
167     /***
168      * Tells this option whether to send a WILL request upon connection.
169      * <p>
170      * @param init - if true, a WILL request will be sent upon subsequent
171      * connections.
172      ***/
173     public void setInitLocal(boolean init)
174     {
175         initialLocal = init;
176     }
177
178     /***
179      * Tells this option whether to send a DO request upon connection.
180      * <p>
181      * @param init - if true, a DO request will be sent upon subsequent
182      * connections.
183      ***/
184     public void setInitRemote(boolean init)
185     {
186         initialRemote = init;
187     }
188
189     /***
190      * Method called upon reception of a subnegotiation for this option
191      * coming from the other end.
192      * Must be implemented by the actual TelnetOptionHandler to specify
193      * which response must be sent for the subnegotiation request.
194      * <p>
195      * @param suboptionData - the sequence received, whithout IAC SB & IAC SE
196      * @param suboptionLength - the length of data in suboption_data
197      * <p>
198      * @return response to be sent to the subnegotiation sequence. TelnetClient
199      * will add IAC SB & IAC SE. null means no response
200      ***/
201     public abstract int[] answerSubnegotiation(int suboptionData[],
202                             int suboptionLength);
203
204     /***
205      * This method is invoked whenever this option is acknowledged active on
206      * the local end (TelnetClient sent a WILL, remote side sent a DO).
207      * The method is used to specify a subnegotiation sequence that will be
208      * sent by TelnetClient when the option is activated.
209      * <p>
210      * @return subnegotiation sequence to be sent by TelnetClient. TelnetClient
211      * will add IAC SB & IAC SE. null means no subnegotiation.
212      ***/
213     public abstract int[] startSubnegotiationLocal();
214
215     /***
216      * This method is invoked whenever this option is acknowledged active on
217      * the remote end (TelnetClient sent a DO, remote side sent a WILL).
218      * The method is used to specify a subnegotiation sequence that will be
219      * sent by TelnetClient when the option is activated.
220      * <p>
221      * @return subnegotiation sequence to be sent by TelnetClient. TelnetClient
222      * will add IAC SB & IAC SE. null means no subnegotiation.
223      ***/
224     public abstract int[] startSubnegotiationRemote();
225
226     /***
227      * Returns a boolean indicating whether a WILL request sent to the other
228      * side has been acknowledged.
229      * <p>
230      * @return true if a WILL sent to the other side has been acknowledged.
231      ***/
232     boolean getWill()
233     {
234         return willFlag;
235     }
236
237     /***
238      * Tells this option whether a WILL request sent to the other
239      * side has been acknowledged (invoked by TelnetClient).
240      * <p>
241      * @param state - if true, a WILL request has been acknowledged.
242      ***/
243     void setWill(boolean state)
244     {
245         willFlag = state;
246     }
247
248     /***
249      * Returns a boolean indicating whether a DO request sent to the other
250      * side has been acknowledged.
251      * <p>
252      * @return true if a DO sent to the other side has been acknowledged.
253      ***/
254     boolean getDo()
255     {
256         return doFlag;
257     }
258
259
260     /***
261      * Tells this option whether a DO request sent to the other
262      * side has been acknowledged (invoked by TelnetClient).
263      * <p>
264      * @param state - if true, a DO request has been acknowledged.
265      ***/
266     void setDo(boolean state)
267     {
268         doFlag = state;
269     }
270 }
271
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