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 1.13 2001/02/07 13:47:33 tdb1 Exp $
 */
class TCPControlHandler extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.13 $";
    
    /**
     * 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(), true);
        // 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 {
            send(PROTOVER);
            _clientName = _socketIn.readLine();
            if(_clientName==null) {
                throw new IOException("Fatal error reading from client");
            }
            sendOK();
        }
        catch(IOException e) {
            _logger.write(toString(), Logger.FATAL, "Fatal error, shutdown pending");
            run=false;
        }
        
        _logger.write(toString(), Logger.DEBUG, "Client has connected: "+_clientName);
        
        // loop until we decide to shutdown (run=false)
        while(run) {
            try {
                String cmd = _socketIn.readLine();
                if(cmd==null) {
                    throw new IOException("Fatal error reading from client");
                }
                // make a decision about what to do
                if(cmd.equals("STARTCONFIG")) {
                    // get the configuration for this client
                    Configuration myConfig = _configManager.getConfiguration("Client."+_clientName);
                    sendOK();
                    // get properties
                    cmd = _socketIn.readLine();
                    if(cmd==null) {
                        throw new IOException("Fatal error reading from client");
                    }
                    // 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);    
                                send(returnedProperty);
                            }
                            catch (org.omg.CORBA.MARSHAL e) {
                                sendERROR();
                            }
                        }
                        else {
                            sendERROR();
                        }
                        cmd = _socketIn.readLine();
                        if(cmd==null) {
                            throw new IOException("Fatal error reading from client");
                        }
                    }
                    sendOK();
                    _logger.write(toString(), Logger.DEBUG, "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
                        String port = new Integer(ss.getLocalPort()).toString();
                        // tell the client the port
                        send(port);
                        // 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);
                        // startup a monitor on the DataHandler's queue, every minute
                        dh.getQueue().startMonitor(60*1000, _packetSorter.getQueue(), _name);
                        // start up the DataHandler
                        dh.start();
                        // Hold a reference to the DataHandler, so we can stop it later
                        _dataHandler = dh;
                        sendOK();
                        _logger.write(toString(), Logger.DEBUG, "Data stream started at Clients Request on port: "+port);
                    }
                    else {
                        sendERROR();
                    }
                }
                else if(cmd.equals("STOPDATA")) {
                    // attempt to close the data channel
                    if(closeData()) {
                        sendOK();
                        _logger.write(toString(), Logger.DEBUG, "Data stream stopped at Clients Request");
                    }
                    else {
                        sendERROR();
                    }
                }
                else if(cmd.equals("SETHOSTLIST")) {
                    // we can only set the host list when
                    // the DataHandler is not connected
                    if(_dataHandler == null) {
                        sendOK();
                        // read and set the host list
                        cmd = _socketIn.readLine();
                        if(cmd==null) {
                            throw new IOException("Fatal error reading from client");
                        }
                        _hostList = cmd;
                        sendOK();
                    }
                    else {
                        sendERROR();
                    }
                }
                else if(cmd.equals("DISCONNECT")) {
                    // we going to disconnect, so lets stop the main loop
                    run=false;
                    // if there is a DataHandler, we'd best shut it down
                    if(closeData()) {
                        _logger.write(toString(), Logger.DEBUG, "Data stream stopped at Clients Request");
                    }
                    // say bye to the client
                    sendOK();
                    // close the reader, writer and Socket
                    _socketIn.close();
                    _socketOut.close();
                    _socket.close();
                    _logger.write(toString(), Logger.DEBUG, "Closing at Clients Request");
                }
                else {
                    sendERROR();
                }
            }
            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.DEBUG, "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---

    /**
     * Attempt to close down the DataHandler. This will return
     * true if it managed to close it down, or false if there
     * wasn't a DataHandler to close.
     *
     * @return whether the channel could be closed
     */
    private boolean closeData() {
        // 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;
            return true;
        }
        else {
            return false;
        }
    }
    
    /**
     * Send an OK message to the outgoing Socket
     */
    private void sendOK() {
        send("OK");
    }
    
    /**
     * Send an ERROR message to the outgoing Socket.
     */
    private void sendERROR() {
        send("ERROR");
    }
    
    /**
     * Send any String message to the outgoing Socket.
     *
     * @param message The message/command to send.
     */
    private void send(String message) {
        _socketOut.println(message);
    }

//---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:	1.14
Committed:	Mon Feb 12 02:23:53 2001 UTC (23 years, 3 months ago) by tdb
Branch:	MAIN
Changes since 1.13:	+4 -2 lines
Log Message:	Now monitor the Queue here every 60 seconds, reporting back to the Queue in the PacketSorter class.
#	User	Rev	Content
1	tdb	1.1	//---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	tdb	1.2	* @author $Author: tdb1 $
22	tdb	1.14	* @version $Id: TCPControlHandler.java,v 1.13 2001/02/07 13:47:33 tdb1 Exp $
23	tdb	1.1	*/
24			class TCPControlHandler extends Thread {
25
26			//---FINAL ATTRIBUTES---
27
28			/**
29			* The current CVS revision of this class
30			*/
31	tdb	1.14	public final String REVISION = "$Revision: 1.13 $";
32	tdb	1.1
33	tdb	1.9	/**
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	tdb	1.4	public static final String PROTOVER = "PROTOCOL 1.1";
39	tdb	1.1
40			//---STATIC METHODS---
41
42			//---CONSTRUCTORS---
43	tdb	1.9
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	tdb	1.1	_socket = socket;
53	tdb	1.9	_packetSorter = packetSorter;
54			// setup the reader & writer
55	tdb	1.1	_socketIn = new BufferedReader(new InputStreamReader(_socket.getInputStream()));
56	tdb	1.13	_socketOut = new PrintWriter(_socket.getOutputStream(), true);
57	tdb	1.9	// set the default hostlist to "all host", for backward compatibility
58	tdb	1.4	_hostList = "";
59	tdb	1.1	_logger.write(toString(), Logger.SYSINIT, "created");
60			}
61
62			//---PUBLIC METHODS---
63	tdb	1.9
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	tdb	1.1	public void run() {
70			boolean run = true;
71	tdb	1.9	// Tell the client our protocol, and ask it for it's name
72	tdb	1.1	try {
73	tdb	1.12	send(PROTOVER);
74	tdb	1.1	_clientName = _socketIn.readLine();
75	tdb	1.11	if(_clientName==null) {
76	tdb	1.10	throw new IOException("Fatal error reading from client");
77			}
78	tdb	1.12	sendOK();
79	tdb	1.1	}
80			catch(IOException e) {
81			_logger.write(toString(), Logger.FATAL, "Fatal error, shutdown pending");
82			run=false;
83			}
84
85	tdb	1.12	_logger.write(toString(), Logger.DEBUG, "Client has connected: "+_clientName);
86	tdb	1.1
87	tdb	1.9	// loop until we decide to shutdown (run=false)
88	tdb	1.1	while(run) {
89			try {
90			String cmd = _socketIn.readLine();
91	tdb	1.10	if(cmd==null) {
92			throw new IOException("Fatal error reading from client");
93			}
94	tdb	1.9	// make a decision about what to do
95	tdb	1.1	if(cmd.equals("STARTCONFIG")) {
96	tdb	1.9	// get the configuration for this client
97	tdb	1.1	Configuration myConfig = _configManager.getConfiguration("Client."+_clientName);
98	tdb	1.12	sendOK();
99	tdb	1.1	// get properties
100			cmd = _socketIn.readLine();
101	tdb	1.10	if(cmd==null) {
102			throw new IOException("Fatal error reading from client");
103			}
104	tdb	1.9	// provide all the requested properties
105	tdb	1.1	while(!cmd.equals("ENDCONFIG")) {
106	tdb	1.9	// client is restricted to this properties
107	tdb	1.7	if(cmd.startsWith("Client.") \|\| cmd.startsWith("Host.")) {
108			try {
109			String returnedProperty = myConfig.getProperty(cmd);
110	tdb	1.12	send(returnedProperty);
111	tdb	1.7	}
112			catch (org.omg.CORBA.MARSHAL e) {
113	tdb	1.12	sendERROR();
114	tdb	1.7	}
115			}
116			else {
117	tdb	1.12	sendERROR();
118	tdb	1.1	}
119			cmd = _socketIn.readLine();
120	tdb	1.10	if(cmd==null) {
121			throw new IOException("Fatal error reading from client");
122			}
123	tdb	1.1	}
124	tdb	1.12	sendOK();
125			_logger.write(toString(), Logger.DEBUG, "Client has been configured");
126	tdb	1.1
127			}
128			else if(cmd.equals("STARTDATA")) {
129	tdb	1.9	// if we don't have a DataHandler, set one up
130	tdb	1.1	if(_dataHandler == null) {
131			// create a serversocket
132			ServerSocket ss = new ServerSocket(0);
133			// get the port
134	tdb	1.12	String port = new Integer(ss.getLocalPort()).toString();
135	tdb	1.9	// tell the client the port
136	tdb	1.12	send(port);
137	tdb	1.9	// wait for the client to connect
138	tdb	1.1	Socket s = ss.accept();
139			// when we get the Socket back, give it to the data thread
140	tdb	1.4	TCPDataHandler dh = new TCPDataHandler(s);
141	tdb	1.9	// register the DataHandler's queue, giving the host list
142			_packetSorter.register(dh.getQueue(), _hostList);
143	tdb	1.14	// startup a monitor on the DataHandler's queue, every minute
144			dh.getQueue().startMonitor(60*1000, _packetSorter.getQueue(), _name);
145	tdb	1.9	// start up the DataHandler
146	tdb	1.2	dh.start();
147	tdb	1.9	// Hold a reference to the DataHandler, so we can stop it later
148	tdb	1.1	_dataHandler = dh;
149	tdb	1.12	sendOK();
150			_logger.write(toString(), Logger.DEBUG, "Data stream started at Clients Request on port: "+port);
151	tdb	1.1	}
152			else {
153	tdb	1.12	sendERROR();
154	tdb	1.1	}
155			}
156			else if(cmd.equals("STOPDATA")) {
157	tdb	1.12	// attempt to close the data channel
158			if(closeData()) {
159			sendOK();
160			_logger.write(toString(), Logger.DEBUG, "Data stream stopped at Clients Request");
161	tdb	1.1	}
162			else {
163	tdb	1.12	sendERROR();
164	tdb	1.1	}
165			}
166	tdb	1.4	else if(cmd.equals("SETHOSTLIST")) {
167	tdb	1.9	// we can only set the host list when
168			// the DataHandler is not connected
169	tdb	1.5	if(_dataHandler == null) {
170	tdb	1.12	sendOK();
171	tdb	1.9	// read and set the host list
172	tdb	1.5	cmd = _socketIn.readLine();
173	tdb	1.10	if(cmd==null) {
174			throw new IOException("Fatal error reading from client");
175			}
176	tdb	1.5	_hostList = cmd;
177	tdb	1.12	sendOK();
178	tdb	1.5	}
179			else {
180	tdb	1.12	sendERROR();
181	tdb	1.5	}
182	tdb	1.4	}
183	tdb	1.2	else if(cmd.equals("DISCONNECT")) {
184	tdb	1.12	// we going to disconnect, so lets stop the main loop
185	tdb	1.1	run=false;
186	tdb	1.9	// if there is a DataHandler, we'd best shut it down
187	tdb	1.12	if(closeData()) {
188			_logger.write(toString(), Logger.DEBUG, "Data stream stopped at Clients Request");
189	tdb	1.3	}
190	tdb	1.12	// say bye to the client
191			sendOK();
192	tdb	1.9	// close the reader, writer and Socket
193	tdb	1.1	_socketIn.close();
194			_socketOut.close();
195			_socket.close();
196	tdb	1.12	_logger.write(toString(), Logger.DEBUG, "Closing at Clients Request");
197	tdb	1.1	}
198			else {
199	tdb	1.12	sendERROR();
200	tdb	1.1	}
201			}
202			catch(IOException e) {
203	tdb	1.9	// if we get an exception, the client has probably left, so we stop
204	tdb	1.8	run=false;
205			_logger.write(toString(), Logger.FATAL, "Fatal communication error, shutdown pending");
206	tdb	1.1	}
207			}
208	tdb	1.12	_logger.write(toString(), Logger.DEBUG, "Shutting down Control Handler, client has gone.");
209	tdb	1.1	}
210
211			/**
212			* Overrides the {@link java.lang.Object#toString() Object.toString()}
213			* method to provide clean logging (every class should have this).
214			*
215			* This uses the uk.ac.ukc.iscream.util.NameFormat class
216			* to format the toString()
217			*
218			* @return the name of this class and its CVS revision
219			*/
220			public String toString() {
221			return FormatName.getName(
222			_name,
223			getClass().getName(),
224			REVISION);
225			}
226
227			//---PRIVATE METHODS---
228	tdb	1.12
229			/**
230			* Attempt to close down the DataHandler. This will return
231			* true if it managed to close it down, or false if there
232			* wasn't a DataHandler to close.
233			*
234			* @return whether the channel could be closed
235			*/
236			private boolean closeData() {
237			// if we have a DataHandler, shut it down
238			if(_dataHandler != null) {
239			// Deregister the DataHandler, giving the host list
240			_packetSorter.deregister(_dataHandler.getQueue(), _hostList);
241			// Shut down the data handler
242			_dataHandler.shutdown();
243			// Destroy our reference, leaving it for the GC
244			_dataHandler = null;
245			return true;
246			}
247			else {
248			return false;
249			}
250			}
251
252			/**
253			* Send an OK message to the outgoing Socket
254			*/
255			private void sendOK() {
256			send("OK");
257			}
258
259			/**
260			* Send an ERROR message to the outgoing Socket.
261			*/
262			private void sendERROR() {
263			send("ERROR");
264			}
265
266			/**
267			* Send any String message to the outgoing Socket.
268			*
269			* @param message The message/command to send.
270			*/
271			private void send(String message) {
272			_socketOut.println(message);
273			}
274	tdb	1.1
275			//---ACCESSOR/MUTATOR METHODS---
276
277			//---ATTRIBUTES---
278
279			/**
280			* This is the friendly identifier of the
281			* component this class is running in.
282			* eg, a Filter may be called "filter1",
283			* If this class does not have an owning
284			* component, a name from the configuration
285			* can be placed here. This name could also
286			* be changed to null for utility classes.
287			*/
288			private String _name = ClientInterfaceMain.NAME;
289
290			/**
291			* This holds a reference to the
292			* system logger that is being used.
293			*/
294			private Logger _logger = ReferenceManager.getInstance().getLogger();
295
296			/**
297			* A reference to the Configuration Manager the system is using
298			*/
299			private ConfigurationManager _configManager = ReferenceManager.getInstance().getCM();
300
301			/**
302			* The socket we are talking on
303			*/
304			private Socket _socket;
305
306			/**
307			* A hook to the inbound data from the socket
308			*/
309			private BufferedReader _socketIn;
310
311			/**
312			* A hook to the outbound stream for the socket
313			*/
314			private PrintWriter _socketOut;
315	tdb	1.4
316	tdb	1.1	/**
317	tdb	1.4	* A reference to the PacketSorter.
318			*/
319	tdb	1.9	private PacketSorter _packetSorter;
320	tdb	1.1
321	tdb	1.9	/**
322			* A reference to the DataHandler, if there is one
323			*/
324	tdb	1.1	private TCPDataHandler _dataHandler;
325
326	tdb	1.9	/**
327			* The name of the Client we're connected to
328			*/
329	tdb	1.1	private String _clientName;
330	tdb	1.9
331			/**
332			* The host list the Client has requested
333			*/
334	tdb	1.4	private String _hostList;
335	tdb	1.1
336			//---STATIC ATTRIBUTES---
337
338			}