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 1.9 2001/01/27 23:30:40 tdb1 Exp $
 */
class TCPControlHandler extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.9 $";
    
    /**
     * 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();
            if(cmd==null) {
                throw new IOException("Fatal error reading from client");
            }
            _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();
                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);
                    _socketOut.println("OK");
                    _socketOut.flush();
                    // 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);    
                                _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();
                        if(cmd==null) {
                            throw new IOException("Fatal error reading from client");
                        }
                    }
                    _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();
                        if(cmd==null) {
                            throw new IOException("Fatal error reading from client");
                        }
                        _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:	1.10
Committed:	Mon Jan 29 02:00:03 2001 UTC (23 years, 4 months ago) by tdb
Branch:	MAIN
Changes since 1.9:	+17 -2 lines
Log Message:	A bit of checking of the input. It's likely that if we get a null back something has gone haywire in the communication. This could probably be done better.
#	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	1.10	* @version $Id: TCPControlHandler.java,v 1.9 2001/01/27 23:30:40 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	1.10	public final String REVISION = "$Revision: 1.9 $";
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			_socketOut = new PrintWriter(_socket.getOutputStream());
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			_socketOut.println(PROTOVER);
74			_socketOut.flush();
75			_clientName = _socketIn.readLine();
76	tdb	1.10	if(cmd==null) {
77			throw new IOException("Fatal error reading from client");
78			}
79	tdb	1.1	_socketOut.println("OK");
80			_socketOut.flush();
81			}
82			catch(IOException e) {
83			_logger.write(toString(), Logger.FATAL, "Fatal error, shutdown pending");
84			run=false;
85			}
86
87			_logger.write(toString(), Logger.SYSMSG, "Client has connected: "+_clientName);
88
89	tdb	1.9	// loop until we decide to shutdown (run=false)
90	tdb	1.1	while(run) {
91			try {
92			String cmd = _socketIn.readLine();
93	tdb	1.10	if(cmd==null) {
94			throw new IOException("Fatal error reading from client");
95			}
96	tdb	1.9	// make a decision about what to do
97	tdb	1.1	if(cmd.equals("STARTCONFIG")) {
98	tdb	1.9	// get the configuration for this client
99	tdb	1.1	Configuration myConfig = _configManager.getConfiguration("Client."+_clientName);
100			_socketOut.println("OK");
101			_socketOut.flush();
102			// get properties
103			cmd = _socketIn.readLine();
104	tdb	1.10	if(cmd==null) {
105			throw new IOException("Fatal error reading from client");
106			}
107	tdb	1.9	// provide all the requested properties
108	tdb	1.1	while(!cmd.equals("ENDCONFIG")) {
109	tdb	1.9	// client is restricted to this properties
110	tdb	1.7	if(cmd.startsWith("Client.") \|\| cmd.startsWith("Host.")) {
111			try {
112			String returnedProperty = myConfig.getProperty(cmd);
113			_socketOut.println(returnedProperty);
114			_socketOut.flush();
115			}
116			catch (org.omg.CORBA.MARSHAL e) {
117			_socketOut.println("ERROR");
118			_socketOut.flush();
119			}
120			}
121			else {
122	tdb	1.1	_socketOut.println("ERROR");
123			_socketOut.flush();
124			}
125			cmd = _socketIn.readLine();
126	tdb	1.10	if(cmd==null) {
127			throw new IOException("Fatal error reading from client");
128			}
129	tdb	1.1	}
130			_socketOut.println("OK");
131			_socketOut.flush();
132			_logger.write(toString(), Logger.SYSMSG, "Client has been configured");
133
134			}
135			else if(cmd.equals("STARTDATA")) {
136	tdb	1.9	// if we don't have a DataHandler, set one up
137	tdb	1.1	if(_dataHandler == null) {
138			// create a serversocket
139			ServerSocket ss = new ServerSocket(0);
140			// get the port
141			int port = ss.getLocalPort();
142	tdb	1.9	// tell the client the port
143	tdb	1.1	_socketOut.println(port);
144			_socketOut.flush();
145	tdb	1.9	// wait for the client to connect
146	tdb	1.1	Socket s = ss.accept();
147			// when we get the Socket back, give it to the data thread
148	tdb	1.4	TCPDataHandler dh = new TCPDataHandler(s);
149	tdb	1.9	// register the DataHandler's queue, giving the host list
150			_packetSorter.register(dh.getQueue(), _hostList);
151			// start up the DataHandler
152	tdb	1.2	dh.start();
153	tdb	1.9	// Hold a reference to the DataHandler, so we can stop it later
154	tdb	1.1	_dataHandler = dh;
155			_socketOut.println("OK");
156			_socketOut.flush();
157			_logger.write(toString(), Logger.SYSMSG, "Data stream started at Clients Request on port: "+port);
158			}
159			else {
160			_socketOut.println("ERROR");
161			_socketOut.flush();
162			}
163			}
164			else if(cmd.equals("STOPDATA")) {
165	tdb	1.9	// if we have a DataHandler, shut it down
166	tdb	1.1	if(_dataHandler != null) {
167	tdb	1.9	// Deregister the DataHandler, giving the host list
168			_packetSorter.deregister(_dataHandler.getQueue(), _hostList);
169	tdb	1.2	// Shut down the data handler
170	tdb	1.1	_dataHandler.shutdown();
171	tdb	1.9	// Destroy our reference, leaving it for the GC
172	tdb	1.1	_dataHandler = null;
173			_socketOut.println("OK");
174			_socketOut.flush();
175			_logger.write(toString(), Logger.SYSMSG, "Data stream stopped at Clients Request");
176			}
177			else {
178			_socketOut.println("ERROR");
179			_socketOut.flush();
180			}
181			}
182	tdb	1.4	else if(cmd.equals("SETHOSTLIST")) {
183	tdb	1.9	// we can only set the host list when
184			// the DataHandler is not connected
185	tdb	1.5	if(_dataHandler == null) {
186			_socketOut.println("OK");
187			_socketOut.flush();
188	tdb	1.9	// read and set the host list
189	tdb	1.5	cmd = _socketIn.readLine();
190	tdb	1.10	if(cmd==null) {
191			throw new IOException("Fatal error reading from client");
192			}
193	tdb	1.5	_hostList = cmd;
194			_socketOut.println("OK");
195			_socketOut.flush();
196			}
197			else {
198			_socketOut.println("ERROR");
199			_socketOut.flush();
200			}
201	tdb	1.4	}
202	tdb	1.2	else if(cmd.equals("DISCONNECT")) {
203	tdb	1.9	// we going to disconnect, so lets stop this loop
204	tdb	1.1	run=false;
205	tdb	1.9	// if there is a DataHandler, we'd best shut it down
206	tdb	1.3	if(_dataHandler != null) {
207	tdb	1.9	// Deregister the DataHandler, giving the host list
208			_packetSorter.deregister(_dataHandler.getQueue(), _hostList);
209	tdb	1.3	// Shut down the data handler
210			_dataHandler.shutdown();
211	tdb	1.9	// Destroy our reference, leaving it for the GC
212	tdb	1.3	_dataHandler = null;
213	tdb	1.8	_socketOut.println("OK");
214			_socketOut.flush();
215	tdb	1.3	_logger.write(toString(), Logger.SYSMSG, "Data stream stopped at Clients Request");
216			}
217	tdb	1.1	_socketOut.println("OK");
218			_socketOut.flush();
219	tdb	1.9	// close the reader, writer and Socket
220	tdb	1.1	_socketIn.close();
221			_socketOut.close();
222			_socket.close();
223			_logger.write(toString(), Logger.SYSMSG, "Closing at Clients Request");
224			}
225			else {
226			_socketOut.println("ERROR");
227			_socketOut.flush();
228			}
229			}
230			catch(IOException e) {
231	tdb	1.9	// if we get an exception, the client has probably left, so we stop
232	tdb	1.8	run=false;
233			_logger.write(toString(), Logger.FATAL, "Fatal communication error, shutdown pending");
234	tdb	1.1	}
235			}
236	tdb	1.8	_logger.write(toString(), Logger.SYSMSG, "Shutting down Control Handler, client has gone.");
237	tdb	1.1	}
238
239			/**
240			* Overrides the {@link java.lang.Object#toString() Object.toString()}
241			* method to provide clean logging (every class should have this).
242			*
243			* This uses the uk.ac.ukc.iscream.util.NameFormat class
244			* to format the toString()
245			*
246			* @return the name of this class and its CVS revision
247			*/
248			public String toString() {
249			return FormatName.getName(
250			_name,
251			getClass().getName(),
252			REVISION);
253			}
254
255			//---PRIVATE METHODS---
256
257			//---ACCESSOR/MUTATOR METHODS---
258
259			//---ATTRIBUTES---
260
261			/**
262			* This is the friendly identifier of the
263			* component this class is running in.
264			* eg, a Filter may be called "filter1",
265			* If this class does not have an owning
266			* component, a name from the configuration
267			* can be placed here. This name could also
268			* be changed to null for utility classes.
269			*/
270			private String _name = ClientInterfaceMain.NAME;
271
272			/**
273			* This holds a reference to the
274			* system logger that is being used.
275			*/
276			private Logger _logger = ReferenceManager.getInstance().getLogger();
277
278			/**
279			* A reference to the Configuration Manager the system is using
280			*/
281			private ConfigurationManager _configManager = ReferenceManager.getInstance().getCM();
282
283			/**
284			* The socket we are talking on
285			*/
286			private Socket _socket;
287
288			/**
289			* A hook to the inbound data from the socket
290			*/
291			private BufferedReader _socketIn;
292
293			/**
294			* A hook to the outbound stream for the socket
295			*/
296			private PrintWriter _socketOut;
297	tdb	1.4
298	tdb	1.1	/**
299	tdb	1.4	* A reference to the PacketSorter.
300			*/
301	tdb	1.9	private PacketSorter _packetSorter;
302	tdb	1.1
303	tdb	1.9	/**
304			* A reference to the DataHandler, if there is one
305			*/
306	tdb	1.1	private TCPDataHandler _dataHandler;
307
308	tdb	1.9	/**
309			* The name of the Client we're connected to
310			*/
311	tdb	1.1	private String _clientName;
312	tdb	1.9
313			/**
314			* The host list the Client has requested
315			*/
316	tdb	1.4	private String _hostList;
317	tdb	1.1
318			//---STATIC ATTRIBUTES---
319
320			}