ChannelManager


1   /*- ChannelManager.java -------------------------------------------+
2    |                                                                 |
3    |  Copyright (C) 2002-2003 Joseph Monti, LlamaChat                |
4    |                     countjoe@users.sourceforge.net              |
5    |                     http://www.42llamas.com/LlamaChat/          |
6    |                                                                 |
7    | This program is free software; you can redistribute it and/or   |
8    | modify it under the terms of the GNU General Public License     |
9    | as published by the Free Software Foundation; either version 2  |
10   | of the License, or (at your option) any later version           |
11   |                                                                 |
12   | This program is distributed in the hope that it will be useful, |
13   | but WITHOUT ANY WARRANTY; without even the implied warranty of  |
14   | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the   |
15   | GNU General Public License for more details.                    |
16   |                                                                 |
17   | A copy of the GNU General Public License may be found in the    |
18   | installation directory named "GNUGPL.txt"                       |
19   |                                                                 |
20   +-----------------------------------------------------------------+
21   */
22  
23  package server;
24  
25  import java.util.Vector  ;
26  import java.util.Hashtable  ;
27  import java.util.Enumeration  ;
28  
29  /* -------------------- JavaDoc Information ----------------------*/
30  /**
31   * This class manages the channels for the server. It allows 3 types
32   * of channels. The first of which, defaultChannel, is limited to
33   * one and is the default channel that users are sent to when
34   * connecting. The second, systemChannels, is a collection of channels
35   * that are perminent and created upon program initialization from
36   * the configuration file. The third, userChannels, are created by users
37   * and can only exist if specified in the system configuration file. When
38   * a userChannel is empty it is deleted.
39   * @author Joseph Monti <a HREF="mailto:countjoe@users.sourceforge.net">countjoe@users.sourceforge.net</a>
40   * @version 0.8
41   */
42  public final class ChannelManager {
43      public static char allowUserChannels;
44      public String   defaultChannel;
45      private int defaultCount;
46      private static Hashtable   systemChannels;
47      private static Hashtable   userChannels;
48      public static final String   eName = "Invalid Channel Name";
49      public static final String   eAllowed = "User Channels not allowed";
50      public static final String   eAdmin = "Admin only operation";
51  
52      /**
53       * Constructor to setup variables
54       */
55      ChannelManager() {
56          allowUserChannels = 'y';
57          defaultChannel = "Lobby";
58          defaultCount = 0;
59          systemChannels = null;
60          userChannels = null;
61      }
62  
63      /**
64       * sets the default channel for the server
65       * @param name  the name of the channel
66       * @return true on success, false otherwise (if its not a valid channeL)
67       */
68      public boolean setDefaultChannel(String   name) {
69          if (!name.equals(defaultChannel) && !isValidChannel(name)) {
70              return false;
71          }
72          defaultChannel = name;
73          return true;
74      }
75  
76      /**
77       * creates a new system channel (if valid name)
78       * @param name  the name of the channel
79           * @param pass  the password for the channel, can be null if no
80           *              password required
81       * @return true on success, false otherwise (if its not a valid channeL)
82       */
83      public boolean addSystemChannel(String   name, String   pass) {
84          if (!isValidChannel(name)) {
85              return false;
86          }
87          if (systemChannels == null) {
88              systemChannels = new Hashtable  ();
89          }
90          systemChannels.put(name, new ChannelManagerItem(pass));
91          return true;
92      }
93  
94      /**
95       * creates a new user channel (if valid name and is allowed)
96       * @param name  the name of the channel
97       * @param pass  the password for the channel, can be null if no
98       *              password required
99       * @param cc    the client requesting the channel
100      * @return null on success, reason otherwise (if its not a valid channeL)
101      */
102     public String   addUserChannel(String   name, String   pass, ClientConnection cc) {
103         if (allowUserChannels == 'n') {
104             return eAllowed;
105         }
106         if (allowUserChannels == 'a' && !cc.isAdmin()) {
107             return eAdmin;
108         }
109         if (!isValidChannel(name)) {
110             return eName;
111         }
112         if (userChannels == null) {
113             userChannels = new Hashtable  ();
114         }
115         userChannels.put(name, new ChannelManagerItem(pass));
116         return null;
117     }
118 
119     /**
120      * adds a user to the specified channel
121      * @param name  the name of the channel
122          * @param pass  the password to use for the channel, can be null
123      * @return true on success, false otherwise (if its not a valid channel,
124          *                                           or invalied passphrase)
125      */
126     public boolean userAdd(String   name, String   pass) {
127         if (defaultChannel.equals(name)) {
128             defaultCount++;
129             return true;
130         }
131 
132         if (systemChannels != null && systemChannels.containsKey(name)) {
133            ChannelManagerItem value = (ChannelManagerItem) systemChannels.get(name);
134             if (value == null) {
135                 return false;
136             }
137            if (value.pass == null || value.pass.equals(pass)) {
138                 value.countpp();
139                 return true;
140             }
141             return false;
142         }
143         if (userChannels != null && userChannels.containsKey(name)) {
144             ChannelManagerItem value = (ChannelManagerItem) userChannels.get(name);
145             if (value == null) {
146                 return false;
147             }
148             if (value.pass == null || value.pass.equals(pass)) {
149                 value.countpp();
150                 return true;
151             }
152         }
153         return false;
154     }
155 
156     /**
157      * removes a user from the specified channel, only used on user channels
158      * @param name  the name of the channel
159      * @return  true when the operation emptied the channel and the channel
160      *          was removed, false if failed or did not empty channel
161      */
162     public boolean userDel(String   name) {
163         if (defaultChannel.equals(name)) {
164             defaultCount--;
165             return false;
166         }
167 
168         if (systemChannels != null && systemChannels.containsKey(name)) {
169             ChannelManagerItem value = (ChannelManagerItem) systemChannels.get(name);
170             if (value != null) {
171                 value.countmm();
172             }
173             return false;
174         }
175         if (userChannels != null && userChannels.containsKey(name)) {
176             ChannelManagerItem value = (ChannelManagerItem) userChannels.get(name);
177             if (value == null) {
178                 return false;
179             }
180             if (value.countmm()) {
181                 userChannels.remove(name);
182                 return true;
183             }
184         }
185         return false;
186     }
187 
188     /**
189      * checks to see if the channel can be created
190      * @param name  the name of the channel
191      * @return true if valid channel
192      */
193     public boolean isValidChannel(String   name) {
194         if (defaultChannel.equals(name) ||
195                 (systemChannels != null && systemChannels.containsKey(name)) ||
196                 (userChannels != null && userChannels.containsKey(name)) ||
197                 name.length() > 12 ||  !name.matches("[\\w_-]+?")) {
198             return false;
199         }
200         return true;
201     }
202 
203     /**
204      * checks to see if the channel exists
205      * @param name  the name of the channel
206          * @return true if channel exists
207      */
208     public boolean channelExists(String   name) {
209         if (defaultChannel.equals(name) ||
210                 (systemChannels != null && systemChannels.containsKey(name)) ||
211                 (userChannels != null && userChannels.containsKey(name))) {
212             return true;
213         }
214         return false;
215     }
216     
217     /**
218      * checks to see if channel has password
219      * @return "" if name has pass, null otherwise
220      */
221     public String   channelHasPass(String   name) {
222         if (defaultChannel.equals(name)) {
223             return null;
224         } else if (systemChannels != null && systemChannels.containsKey(name)) {
225             ChannelManagerItem value = (ChannelManagerItem) systemChannels.get(name);
226             if (value != null) {
227                 if (value.pass != null) {
228                     return "";
229                 }
230             }
231             return null;
232         } else if (userChannels != null && userChannels.containsKey(name)) {
233             ChannelManagerItem value = (ChannelManagerItem) userChannels.get(name);
234             if (value != null) {
235                 if (value.pass != null) {
236                     return "";
237                 }
238             }
239             return null;
240         }
241         return null;
242     }
243 
244     /**
245      * returns an enumeration of all the contained channels
246      * @return an enumeration of all contained channels
247      */
248     public Enumeration   enumerate() {
249         Vector   all = new Vector  ();
250         all.add(defaultChannel);
251         if (systemChannels != null) {
252             Enumeration   e = systemChannels.keys();
253             while (e.hasMoreElements()) {
254                 all.add(e.nextElement());
255             }
256         }
257         if (userChannels != null) {
258             Enumeration   e = userChannels.keys();
259             while (e.hasMoreElements()) {
260                 all.add(e.nextElement());
261             }
262         }
263         return all.elements();
264     }
265 
266     /**
267      * storage class for placing in a HashTable
268      */
269     public class ChannelManagerItem {
270         /**
271          * number of users connected
272          */
273         public int count;
274 
275         /**
276          * password for channel, null for no password
277          */
278         public String   pass;
279 
280         /**
281          * default constructor for default initialization
282          */
283         ChannelManagerItem() {
284             count = 0;
285             pass = null;
286         }
287 
288         /**
289          * creates a new channelmanageritem with p as its password
290          * @param p     the password
291          */
292         ChannelManagerItem(String   p) {
293             count = 0;
294             pass = (p == null ? null : new String  (p));
295         }
296 
297         /**
298          * increment the user count
299          */
300         public void countpp() {
301             count++;
302         }
303 
304         /**
305          * decrement the user count
306          * @return true if decrement emptied room
307          */
308         public boolean countmm() {
309             count--;
310             if (count == 0)
311                 return true;
312             return false;
313         }
314     }
315 }
316 
317
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags