server/clientinterface/TCPControlHandler.java

//---PACKAGE DECLARATION---
package uk.ac.ukc.iscream.clientinterface;

//---IMPORTS---
import uk.ac.ukc.iscream.util.*;
import uk.ac.ukc.iscream.componentmanager.*;
import uk.ac.ukc.iscream.core.*;
import java.net.Socket;
import java.net.ServerSocket;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.PrintWriter;
import java.io.InputStreamReader;


/**
 * Acts as a Control Handler to a TCP based client.
 *
 * @author  $Author: tdb1 $
 * @version $Id: TCPControlHandler.java,v 1.8 2001/01/24 00:55:33 tdb1 Exp $
 */
class TCPControlHandler extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.8 $";
    
    /**
     * This is our protocol version. It is hardcoded to ensure
     * that it doesn't get accidently changed. A change to the
     * protocol would also require changing this classes code !
     */
    public static final String PROTOVER = "PROTOCOL 1.1";
    
//---STATIC METHODS---

//---CONSTRUCTORS---
    
    /**
     * Construct a new TCPControlHandler, and setup the reader
     * and writer for the new Socket.
     *
     * @param socket The Socket connected to the new Client
     * @param packetSorter A reference to the PacketSorter in the component
     */
    public TCPControlHandler(Socket socket, PacketSorter packetSorter) throws IOException {
        _socket = socket;
        _packetSorter = packetSorter;
        // setup the reader & writer
        _socketIn = new BufferedReader(new InputStreamReader(_socket.getInputStream()));
        _socketOut = new PrintWriter(_socket.getOutputStream());
        // set the default hostlist to "all host", for backward compatibility
        _hostList = "";
        _logger.write(toString(), Logger.SYSINIT, "created");
    }
    
//---PUBLIC METHODS---
    
    /**
     * This method initiates the thread, setting things up, and then
     * reading commands from the Client. It handles setting up of the
     * DataHandler, and clean shutting down.
     */
    public void run() {
        boolean run = true;
        // Tell the client our protocol, and ask it for it's name
        try {
            _socketOut.println(PROTOVER);
            _socketOut.flush();
            _clientName = _socketIn.readLine();
            _socketOut.println("OK");
            _socketOut.flush();
        }
        catch(IOException e) {
            _logger.write(toString(), Logger.FATAL, "Fatal error, shutdown pending");
            run=false;
        }
        
        _logger.write(toString(), Logger.SYSMSG, "Client has connected: "+_clientName);
        
        // loop until we decide to shutdown (run=false)
        while(run) {
            try {
                String cmd = _socketIn.readLine();
                // make a decision about what to do
                if(cmd.equals("STARTCONFIG")) {
                    // get the configuration for this client
                    Configuration myConfig = _configManager.getConfiguration("Client."+_clientName);
                    _socketOut.println("OK");
                    _socketOut.flush();
                    // get properties
                    cmd = _socketIn.readLine();
                    // provide all the requested properties
                    while(!cmd.equals("ENDCONFIG")) {
                        // client is restricted to this properties
                        if(cmd.startsWith("Client.") || cmd.startsWith("Host.")) {
                            try {
                                String returnedProperty = myConfig.getProperty(cmd);    
                                _socketOut.println(returnedProperty);
                                _socketOut.flush();
                            }
                            catch (org.omg.CORBA.MARSHAL e) {
                                _socketOut.println("ERROR");
                                _socketOut.flush();
                            }
                        }
                        else {
                            _socketOut.println("ERROR");
                            _socketOut.flush();
                        }
                        cmd = _socketIn.readLine();
                    }
                    _socketOut.println("OK");
                    _socketOut.flush();
                    _logger.write(toString(), Logger.SYSMSG, "Client has been configured");
                    
                }
                else if(cmd.equals("STARTDATA")) {
                    // if we don't have a DataHandler, set one up
                    if(_dataHandler == null) {
                        // create a serversocket
                        ServerSocket ss = new ServerSocket(0);
                        // get the port
                        int port = ss.getLocalPort();
                        // tell the client the port
                        _socketOut.println(port);
                        _socketOut.flush();
                        // wait for the client to connect
                        Socket s = ss.accept();
                        // when we get the Socket back, give it to the data thread
                        TCPDataHandler dh = new TCPDataHandler(s);
                        // register the DataHandler's queue, giving the host list
                        _packetSorter.register(dh.getQueue(), _hostList);
                        // start up the DataHandler
                        dh.start();
                        // Hold a reference to the DataHandler, so we can stop it later
                        _dataHandler = dh;
                        _socketOut.println("OK");
                        _socketOut.flush();
                        _logger.write(toString(), Logger.SYSMSG, "Data stream started at Clients Request on port: "+port);
                    }
                    else {
                        _socketOut.println("ERROR");
                        _socketOut.flush();
                    }
                }
                else if(cmd.equals("STOPDATA")) {
                    // if we have a DataHandler, shut it down
                    if(_dataHandler != null) {
                        // Deregister the DataHandler, giving the host list
                        _packetSorter.deregister(_dataHandler.getQueue(), _hostList);
                        // Shut down the data handler
                        _dataHandler.shutdown();
                        // Destroy our reference, leaving it for the GC
                        _dataHandler = null;
                        _socketOut.println("OK");
                        _socketOut.flush();
                        _logger.write(toString(), Logger.SYSMSG, "Data stream stopped at Clients Request");
                    }
                    else {
                        _socketOut.println("ERROR");
                        _socketOut.flush();
                    }
                }
                else if(cmd.equals("SETHOSTLIST")) {
                    // we can only set the host list when
                    // the DataHandler is not connected
                    if(_dataHandler == null) {
                        _socketOut.println("OK");
                        _socketOut.flush();
                        // read and set the host list
                        cmd = _socketIn.readLine();
                        _hostList = cmd;
                        _socketOut.println("OK");
                        _socketOut.flush();
                    }
                    else {
                        _socketOut.println("ERROR");
                        _socketOut.flush();
                    }
                }
                else if(cmd.equals("DISCONNECT")) {
                    // we going to disconnect, so lets stop this loop
                    run=false;
                    // if there is a DataHandler, we'd best shut it down
                    if(_dataHandler != null) {
                        // Deregister the DataHandler, giving the host list
                        _packetSorter.deregister(_dataHandler.getQueue(), _hostList);
                        // Shut down the data handler
                        _dataHandler.shutdown();
                        // Destroy our reference, leaving it for the GC
                        _dataHandler = null;
                        _socketOut.println("OK");
                        _socketOut.flush();
                        _logger.write(toString(), Logger.SYSMSG, "Data stream stopped at Clients Request");
                    }
                    _socketOut.println("OK");
                    _socketOut.flush();
                    // close the reader, writer and Socket
                    _socketIn.close();
                    _socketOut.close();
                    _socket.close();
                    _logger.write(toString(), Logger.SYSMSG, "Closing at Clients Request");
                }
                else {
                    _socketOut.println("ERROR");
                    _socketOut.flush();
                }
            }
            catch(IOException e) {
                // if we get an exception, the client has probably left, so we stop
                run=false;
                _logger.write(toString(), Logger.FATAL, "Fatal communication error, shutdown pending");
            }
        }
        _logger.write(toString(), Logger.SYSMSG, "Shutting down Control Handler, client has gone.");
    }
  
    /**
     * Overrides the {@link java.lang.Object#toString() Object.toString()}
     * method to provide clean logging (every class should have this).
     *
     * This uses the uk.ac.ukc.iscream.util.NameFormat class
     * to format the toString()
     *
     * @return the name of this class and its CVS revision
     */
    public String toString() {
        return FormatName.getName(
            _name,
            getClass().getName(),
            REVISION);
    }

//---PRIVATE METHODS---

//---ACCESSOR/MUTATOR METHODS---

//---ATTRIBUTES---

    /**
     * This is the friendly identifier of the
     * component this class is running in.
     * eg, a Filter may be called "filter1",
     * If this class does not have an owning
     * component,  a name from the configuration
     * can be placed here.  This name could also
     * be changed to null for utility classes.
     */
    private String _name = ClientInterfaceMain.NAME;
    
    /**
     * This holds a reference to the
     * system logger that is being used.
     */
    private Logger _logger = ReferenceManager.getInstance().getLogger();
    
    /**
     * A reference to the Configuration Manager the system is using
     */
    private ConfigurationManager _configManager = ReferenceManager.getInstance().getCM();
    
    /**
     * The socket we are talking on
     */
    private Socket _socket;

    /**
     * A hook to the inbound data from the socket
     */
    private BufferedReader _socketIn;

    /**
     * A hook to the outbound stream for the socket
     */
    private PrintWriter _socketOut;
    
    /**
         * A reference to the PacketSorter.
         */
    private PacketSorter _packetSorter;
    
    /**
     * A reference to the DataHandler, if there is one
     */
    private TCPDataHandler _dataHandler;
    
    /**
     * The name of the Client we're connected to
     */
    private String _clientName;
    
    /**
     * The host list the Client has requested
     */
    private String _hostList;
    
//---STATIC ATTRIBUTES---

}
Revision:	1.9
Committed:	Sat Jan 27 23:30:40 2001 UTC (23 years, 4 months ago) by tdb
Branch:	MAIN
Changes since 1.8:	+63 -22 lines
Log Message:	All of these classes have been javadoc'd and commented.
#	Content
1	//---PACKAGE DECLARATION---
2	package uk.ac.ukc.iscream.clientinterface;
3
4	//---IMPORTS---
5	import uk.ac.ukc.iscream.util.*;
6	import uk.ac.ukc.iscream.componentmanager.*;
7	import uk.ac.ukc.iscream.core.*;
8	import java.net.Socket;
9	import java.net.ServerSocket;
10	import java.io.InputStream;
11	import java.io.OutputStream;
12	import java.io.IOException;
13	import java.io.BufferedReader;
14	import java.io.PrintWriter;
15	import java.io.InputStreamReader;
16
17
18	/**
19	* Acts as a Control Handler to a TCP based client.
20	*
21	* @author $Author: tdb1 $
22	* @version $Id: TCPControlHandler.java,v 1.8 2001/01/24 00:55:33 tdb1 Exp $
23	*/
24	class TCPControlHandler extends Thread {
25
26	//---FINAL ATTRIBUTES---
27
28	/**
29	* The current CVS revision of this class
30	*/
31	public final String REVISION = "$Revision: 1.8 $";
32
33	/**
34	* This is our protocol version. It is hardcoded to ensure
35	* that it doesn't get accidently changed. A change to the
36	* protocol would also require changing this classes code !
37	*/
38	public static final String PROTOVER = "PROTOCOL 1.1";
39
40	//---STATIC METHODS---
41
42	//---CONSTRUCTORS---
43
44	/**
45	* Construct a new TCPControlHandler, and setup the reader
46	* and writer for the new Socket.
47	*
48	* @param socket The Socket connected to the new Client
49	* @param packetSorter A reference to the PacketSorter in the component
50	*/
51	public TCPControlHandler(Socket socket, PacketSorter packetSorter) throws IOException {
52	_socket = socket;
53	_packetSorter = packetSorter;
54	// setup the reader & writer
55	_socketIn = new BufferedReader(new InputStreamReader(_socket.getInputStream()));
56	_socketOut = new PrintWriter(_socket.getOutputStream());
57	// set the default hostlist to "all host", for backward compatibility
58	_hostList = "";
59	_logger.write(toString(), Logger.SYSINIT, "created");
60	}
61
62	//---PUBLIC METHODS---
63
64	/**
65	* This method initiates the thread, setting things up, and then
66	* reading commands from the Client. It handles setting up of the
67	* DataHandler, and clean shutting down.
68	*/
69	public void run() {
70	boolean run = true;
71	// Tell the client our protocol, and ask it for it's name
72	try {
73	_socketOut.println(PROTOVER);
74	_socketOut.flush();
75	_clientName = _socketIn.readLine();
76	_socketOut.println("OK");
77	_socketOut.flush();
78	}
79	catch(IOException e) {
80	_logger.write(toString(), Logger.FATAL, "Fatal error, shutdown pending");
81	run=false;
82	}
83
84	_logger.write(toString(), Logger.SYSMSG, "Client has connected: "+_clientName);
85
86	// loop until we decide to shutdown (run=false)
87	while(run) {
88	try {
89	String cmd = _socketIn.readLine();
90	// make a decision about what to do
91	if(cmd.equals("STARTCONFIG")) {
92	// get the configuration for this client
93	Configuration myConfig = _configManager.getConfiguration("Client."+_clientName);
94	_socketOut.println("OK");
95	_socketOut.flush();
96	// get properties
97	cmd = _socketIn.readLine();
98	// provide all the requested properties
99	while(!cmd.equals("ENDCONFIG")) {
100	// client is restricted to this properties
101	if(cmd.startsWith("Client.") \|\| cmd.startsWith("Host.")) {
102	try {
103	String returnedProperty = myConfig.getProperty(cmd);
104	_socketOut.println(returnedProperty);
105	_socketOut.flush();
106	}
107	catch (org.omg.CORBA.MARSHAL e) {
108	_socketOut.println("ERROR");
109	_socketOut.flush();
110	}
111	}
112	else {
113	_socketOut.println("ERROR");
114	_socketOut.flush();
115	}
116	cmd = _socketIn.readLine();
117	}
118	_socketOut.println("OK");
119	_socketOut.flush();
120	_logger.write(toString(), Logger.SYSMSG, "Client has been configured");
121
122	}
123	else if(cmd.equals("STARTDATA")) {
124	// if we don't have a DataHandler, set one up
125	if(_dataHandler == null) {
126	// create a serversocket
127	ServerSocket ss = new ServerSocket(0);
128	// get the port
129	int port = ss.getLocalPort();
130	// tell the client the port
131	_socketOut.println(port);
132	_socketOut.flush();
133	// wait for the client to connect
134	Socket s = ss.accept();
135	// when we get the Socket back, give it to the data thread
136	TCPDataHandler dh = new TCPDataHandler(s);
137	// register the DataHandler's queue, giving the host list
138	_packetSorter.register(dh.getQueue(), _hostList);
139	// start up the DataHandler
140	dh.start();
141	// Hold a reference to the DataHandler, so we can stop it later
142	_dataHandler = dh;
143	_socketOut.println("OK");
144	_socketOut.flush();
145	_logger.write(toString(), Logger.SYSMSG, "Data stream started at Clients Request on port: "+port);
146	}
147	else {
148	_socketOut.println("ERROR");
149	_socketOut.flush();
150	}
151	}
152	else if(cmd.equals("STOPDATA")) {
153	// if we have a DataHandler, shut it down
154	if(_dataHandler != null) {
155	// Deregister the DataHandler, giving the host list
156	_packetSorter.deregister(_dataHandler.getQueue(), _hostList);
157	// Shut down the data handler
158	_dataHandler.shutdown();
159	// Destroy our reference, leaving it for the GC
160	_dataHandler = null;
161	_socketOut.println("OK");
162	_socketOut.flush();
163	_logger.write(toString(), Logger.SYSMSG, "Data stream stopped at Clients Request");
164	}
165	else {
166	_socketOut.println("ERROR");
167	_socketOut.flush();
168	}
169	}
170	else if(cmd.equals("SETHOSTLIST")) {
171	// we can only set the host list when
172	// the DataHandler is not connected
173	if(_dataHandler == null) {
174	_socketOut.println("OK");
175	_socketOut.flush();
176	// read and set the host list
177	cmd = _socketIn.readLine();
178	_hostList = cmd;
179	_socketOut.println("OK");
180	_socketOut.flush();
181	}
182	else {
183	_socketOut.println("ERROR");
184	_socketOut.flush();
185	}
186	}
187	else if(cmd.equals("DISCONNECT")) {
188	// we going to disconnect, so lets stop this loop
189	run=false;
190	// if there is a DataHandler, we'd best shut it down
191	if(_dataHandler != null) {
192	// Deregister the DataHandler, giving the host list
193	_packetSorter.deregister(_dataHandler.getQueue(), _hostList);
194	// Shut down the data handler
195	_dataHandler.shutdown();
196	// Destroy our reference, leaving it for the GC
197	_dataHandler = null;
198	_socketOut.println("OK");
199	_socketOut.flush();
200	_logger.write(toString(), Logger.SYSMSG, "Data stream stopped at Clients Request");
201	}
202	_socketOut.println("OK");
203	_socketOut.flush();
204	// close the reader, writer and Socket
205	_socketIn.close();
206	_socketOut.close();
207	_socket.close();
208	_logger.write(toString(), Logger.SYSMSG, "Closing at Clients Request");
209	}
210	else {
211	_socketOut.println("ERROR");
212	_socketOut.flush();
213	}
214	}
215	catch(IOException e) {
216	// if we get an exception, the client has probably left, so we stop
217	run=false;
218	_logger.write(toString(), Logger.FATAL, "Fatal communication error, shutdown pending");
219	}
220	}
221	_logger.write(toString(), Logger.SYSMSG, "Shutting down Control Handler, client has gone.");
222	}
223
224	/**
225	* Overrides the {@link java.lang.Object#toString() Object.toString()}
226	* method to provide clean logging (every class should have this).
227	*
228	* This uses the uk.ac.ukc.iscream.util.NameFormat class
229	* to format the toString()
230	*
231	* @return the name of this class and its CVS revision
232	*/
233	public String toString() {
234	return FormatName.getName(
235	_name,
236	getClass().getName(),
237	REVISION);
238	}
239
240	//---PRIVATE METHODS---
241
242	//---ACCESSOR/MUTATOR METHODS---
243
244	//---ATTRIBUTES---
245
246	/**
247	* This is the friendly identifier of the
248	* component this class is running in.
249	* eg, a Filter may be called "filter1",
250	* If this class does not have an owning
251	* component, a name from the configuration
252	* can be placed here. This name could also
253	* be changed to null for utility classes.
254	*/
255	private String _name = ClientInterfaceMain.NAME;
256
257	/**
258	* This holds a reference to the
259	* system logger that is being used.
260	*/
261	private Logger _logger = ReferenceManager.getInstance().getLogger();
262
263	/**
264	* A reference to the Configuration Manager the system is using
265	*/
266	private ConfigurationManager _configManager = ReferenceManager.getInstance().getCM();
267
268	/**
269	* The socket we are talking on
270	*/
271	private Socket _socket;
272
273	/**
274	* A hook to the inbound data from the socket
275	*/
276	private BufferedReader _socketIn;
277
278	/**
279	* A hook to the outbound stream for the socket
280	*/
281	private PrintWriter _socketOut;
282
283	/**
284	* A reference to the PacketSorter.
285	*/
286	private PacketSorter _packetSorter;
287
288	/**
289	* A reference to the DataHandler, if there is one
290	*/
291	private TCPDataHandler _dataHandler;
292
293	/**
294	* The name of the Client we're connected to
295	*/
296	private String _clientName;
297
298	/**
299	* The host list the Client has requested
300	*/
301	private String _hostList;
302
303	//---STATIC ATTRIBUTES---
304
305	}