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Java > Open Source Codes > org > apache > commons > net > time > TimeTestSimpleServer


1 package org.apache.commons.net.time;
2
3 /* ====================================================================
4  *
5  * The Apache Software License, Version 1.1
6  *
7  * Copyright (c) 2003 The Apache Software Foundation. All rights
8  * reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  *
14  * 1. Redistributions of source code must retain the above copyright
15  * notice, this list of conditions and the following disclaimer.
16  *
17  * 2. Redistributions in binary form must reproduce the above copyright
18  * notice, this list of conditions and the following disclaimer in
19  * the documentation and/or other materials provided with the
20  * distribution.
21  *
22  * 3. The end-user documentation included with the redistribution, if
23  * any, must include the following acknowlegement:
24  * "This product includes software developed by the
25  * Apache Software Foundation (http://www.apache.org/)."
26  * Alternately, this acknowlegement may appear in the software itself,
27  * if and wherever such third-party acknowlegements normally appear.
28  *
29  * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
30  * Foundation" must not be used to endorse or promote products derived
31  * from this software without prior written permission. For written
32  * permission, please contact apache@apache.org.
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34  * 5. Products derived from this software may not be called "Apache"
35  * nor may "Apache" appear in their names without prior written
36  * permission of the Apache Group.
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38  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
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52  * This software consists of voluntary contributions made by many
53  * individuals on behalf of the Apache Software Foundation. For more
54  * information on the Apache Software Foundation, please see
55  * <http://www.apache.org/>.
56  */
57
58 import java.io.DataOutputStream JavaDoc;
59 import java.io.IOException JavaDoc;
60 import java.net.ServerSocket JavaDoc;
61 import java.net.Socket JavaDoc;
62
63 /**
64  * The TimetSimpleServer class is a simple TCP implementation of a server
65  * for the Time Protocol described in RFC 868.
66  * <p>
67  * Listens for TCP socket connections on the time protocol port and writes
68  * the local time to socket outputStream as 32-bit integer of seconds
69  * since midnight on 1 January 1900 GMT.
70  * See <A HREF="ftp://ftp.rfc-editor.org/in-notes/rfc868.txt"> the spec </A> for
71  * details.
72  * <p>
73  * Note this is for <B>debugging purposes only</B> and not meant to be run as a realiable time service.
74  *
75  * @author Jason Mathews, MITRE Corporation
76  *
77  * @version $Revision: 1.1 $ $Date: 2003/09/24 21:51:48 $
78  */
79 public class TimeTestSimpleServer implements Runnable JavaDoc
80 {
81
82     /**
83      * baseline time 1900-01-01T00:00:00 UTC
84      */
85     public static final long SECONDS_1900_TO_1970 = 2208988800L;
86
87     /*** The default time port. It is set to 37 according to RFC 868. ***/
88     public static final int DEFAULT_PORT = 37;
89
90     private ServerSocket JavaDoc server;
91     private int port;
92     private boolean running = false;
93
94     /**
95      * Default constructor for TimetSimpleServer.
96      * Initializes port to defaul time port.
97      */
98     public TimeTestSimpleServer()
99     {
100         port = DEFAULT_PORT;
101     }
102
103     /**
104      * Constructor for TimetSimpleServer given a specific port.
105      */
106     public TimeTestSimpleServer(int port)
107     {
108         this.port = port;
109     }
110
111     public void connect() throws IOException JavaDoc
112     {
113         if (server == null)
114         {
115             server = new ServerSocket JavaDoc(port);
116         }
117     }
118
119     public int getPort()
120     {
121         return server == null ? port : server.getLocalPort();
122     }
123
124     public boolean isRunning()
125     {
126         return running;
127     }
128
129     /**
130      * Start time service and provide time to client connections.
131      * @throws IOException
132      */
133     public void start() throws IOException JavaDoc
134     {
135         if (server == null)
136     {
137             connect();
138     }
139     if (!running)
140     {
141         running = true;
142         new Thread JavaDoc(this).start();
143     }
144     }
145
146     public void run()
147     {
148         Socket JavaDoc socket = null;
149         while (running)
150         {
151             try
152             {
153                 socket = server.accept();
154                 DataOutputStream JavaDoc os = new DataOutputStream JavaDoc(socket.getOutputStream());
155                 // add 500 ms to round off to nearest second
156 int time = (int) ((System.currentTimeMillis() + 500) / 1000 + SECONDS_1900_TO_1970);
157                 os.writeInt(time);
158                 os.flush();
159             } catch (IOException JavaDoc e)
160             {
161             } finally
162             {
163                 if (socket != null)
164                     try
165                     {
166                         socket.close(); // force closing of the socket
167 } catch (IOException JavaDoc e)
168                     {
169                         System.err.println("close socket error: " + e);
170                     }
171             }
172         }
173     }
174
175     /**
176      * Close server socket.
177      */
178     public void stop()
179     {
180         running = false;
181         if (server != null)
182         {
183             try
184             {
185                 server.close(); // force closing of the socket
186 } catch (IOException JavaDoc e)
187             {
188                 System.err.println("close socket error: " + e);
189             }
190             server = null;
191         }
192     }
193
194     public static void main(String JavaDoc[] args)
195     {
196         TimeTestSimpleServer server = new TimeTestSimpleServer();
197         try
198         {
199             server.start();
200         } catch (IOException JavaDoc e)
201         {
202         }
203     }
204
205 }
206
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