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 1.14 2001/02/12 02:23:53 tdb1 Exp $
 */
class TCPControlHandler extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.14 $";
    
    /**
     * 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
     * @param queueMonitorInterval The interval at which to monitor our Queue
     */
    public TCPControlHandler(Socket socket, PacketSorter packetSorter, int queueMonitorInterval) throws IOException {
        _socket = socket;
        _packetSorter = packetSorter;
        _queueMonitorInterval = queueMonitorInterval;
        // 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
                        String queueName = _name + " TCPHandler:"+_socket.getInetAddress().getHostName();
                        dh.getQueue().startMonitor(_queueMonitorInterval*1000, _packetSorter.getQueue(), queueName);
                        // 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;
    
    /**
     * The interval at which to monitor our Queue
     */
    private int _queueMonitorInterval;
    
//---STATIC ATTRIBUTES---

}
Revision:	1.15
Committed:	Wed Feb 21 19:11:28 2001 UTC (23 years, 3 months ago) by tdb
Branch:	MAIN
Changes since 1.14:	+12 -4 lines
Log Message:	Modification to the Queue system; - interval of monitor is now configurable. - attempt to identify each Queue better, although this is still hard.
#	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 1.14 2001/02/12 02:23:53 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: 1.14 $";
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	* @param queueMonitorInterval The interval at which to monitor our Queue
51	*/
52	public TCPControlHandler(Socket socket, PacketSorter packetSorter, int queueMonitorInterval) throws IOException {
53	_socket = socket;
54	_packetSorter = packetSorter;
55	_queueMonitorInterval = queueMonitorInterval;
56	// setup the reader & writer
57	_socketIn = new BufferedReader(new InputStreamReader(_socket.getInputStream()));
58	_socketOut = new PrintWriter(_socket.getOutputStream(), true);
59	// set the default hostlist to "all host", for backward compatibility
60	_hostList = "";
61	_logger.write(toString(), Logger.SYSINIT, "created");
62	}
63
64	//---PUBLIC METHODS---
65
66	/**
67	* This method initiates the thread, setting things up, and then
68	* reading commands from the Client. It handles setting up of the
69	* DataHandler, and clean shutting down.
70	*/
71	public void run() {
72	boolean run = true;
73	// Tell the client our protocol, and ask it for it's name
74	try {
75	send(PROTOVER);
76	_clientName = _socketIn.readLine();
77	if(_clientName==null) {
78	throw new IOException("Fatal error reading from client");
79	}
80	sendOK();
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.DEBUG, "Client has connected: "+_clientName);
88
89	// loop until we decide to shutdown (run=false)
90	while(run) {
91	try {
92	String cmd = _socketIn.readLine();
93	if(cmd==null) {
94	throw new IOException("Fatal error reading from client");
95	}
96	// make a decision about what to do
97	if(cmd.equals("STARTCONFIG")) {
98	// get the configuration for this client
99	Configuration myConfig = _configManager.getConfiguration("Client."+_clientName);
100	sendOK();
101	// get properties
102	cmd = _socketIn.readLine();
103	if(cmd==null) {
104	throw new IOException("Fatal error reading from client");
105	}
106	// provide all the requested properties
107	while(!cmd.equals("ENDCONFIG")) {
108	// client is restricted to this properties
109	if(cmd.startsWith("Client.") \|\| cmd.startsWith("Host.")) {
110	try {
111	String returnedProperty = myConfig.getProperty(cmd);
112	send(returnedProperty);
113	}
114	catch (org.omg.CORBA.MARSHAL e) {
115	sendERROR();
116	}
117	}
118	else {
119	sendERROR();
120	}
121	cmd = _socketIn.readLine();
122	if(cmd==null) {
123	throw new IOException("Fatal error reading from client");
124	}
125	}
126	sendOK();
127	_logger.write(toString(), Logger.DEBUG, "Client has been configured");
128
129	}
130	else if(cmd.equals("STARTDATA")) {
131	// if we don't have a DataHandler, set one up
132	if(_dataHandler == null) {
133	// create a serversocket
134	ServerSocket ss = new ServerSocket(0);
135	// get the port
136	String port = new Integer(ss.getLocalPort()).toString();
137	// tell the client the port
138	send(port);
139	// wait for the client to connect
140	Socket s = ss.accept();
141	// when we get the Socket back, give it to the data thread
142	TCPDataHandler dh = new TCPDataHandler(s);
143	// register the DataHandler's queue, giving the host list
144	_packetSorter.register(dh.getQueue(), _hostList);
145	// startup a monitor on the DataHandler's queue, every minute
146	String queueName = _name + " TCPHandler:"+_socket.getInetAddress().getHostName();
147	dh.getQueue().startMonitor(_queueMonitorInterval*1000, _packetSorter.getQueue(), queueName);
148	// start up the DataHandler
149	dh.start();
150	// Hold a reference to the DataHandler, so we can stop it later
151	_dataHandler = dh;
152	sendOK();
153	_logger.write(toString(), Logger.DEBUG, "Data stream started at Clients Request on port: "+port);
154	}
155	else {
156	sendERROR();
157	}
158	}
159	else if(cmd.equals("STOPDATA")) {
160	// attempt to close the data channel
161	if(closeData()) {
162	sendOK();
163	_logger.write(toString(), Logger.DEBUG, "Data stream stopped at Clients Request");
164	}
165	else {
166	sendERROR();
167	}
168	}
169	else if(cmd.equals("SETHOSTLIST")) {
170	// we can only set the host list when
171	// the DataHandler is not connected
172	if(_dataHandler == null) {
173	sendOK();
174	// read and set the host list
175	cmd = _socketIn.readLine();
176	if(cmd==null) {
177	throw new IOException("Fatal error reading from client");
178	}
179	_hostList = cmd;
180	sendOK();
181	}
182	else {
183	sendERROR();
184	}
185	}
186	else if(cmd.equals("DISCONNECT")) {
187	// we going to disconnect, so lets stop the main loop
188	run=false;
189	// if there is a DataHandler, we'd best shut it down
190	if(closeData()) {
191	_logger.write(toString(), Logger.DEBUG, "Data stream stopped at Clients Request");
192	}
193	// say bye to the client
194	sendOK();
195	// close the reader, writer and Socket
196	_socketIn.close();
197	_socketOut.close();
198	_socket.close();
199	_logger.write(toString(), Logger.DEBUG, "Closing at Clients Request");
200	}
201	else {
202	sendERROR();
203	}
204	}
205	catch(IOException e) {
206	// if we get an exception, the client has probably left, so we stop
207	run=false;
208	_logger.write(toString(), Logger.FATAL, "Fatal communication error, shutdown pending");
209	}
210	}
211	_logger.write(toString(), Logger.DEBUG, "Shutting down Control Handler, client has gone.");
212	}
213
214	/**
215	* Overrides the {@link java.lang.Object#toString() Object.toString()}
216	* method to provide clean logging (every class should have this).
217	*
218	* This uses the uk.ac.ukc.iscream.util.NameFormat class
219	* to format the toString()
220	*
221	* @return the name of this class and its CVS revision
222	*/
223	public String toString() {
224	return FormatName.getName(
225	_name,
226	getClass().getName(),
227	REVISION);
228	}
229
230	//---PRIVATE METHODS---
231
232	/**
233	* Attempt to close down the DataHandler. This will return
234	* true if it managed to close it down, or false if there
235	* wasn't a DataHandler to close.
236	*
237	* @return whether the channel could be closed
238	*/
239	private boolean closeData() {
240	// if we have a DataHandler, shut it down
241	if(_dataHandler != null) {
242	// Deregister the DataHandler, giving the host list
243	_packetSorter.deregister(_dataHandler.getQueue(), _hostList);
244	// Shut down the data handler
245	_dataHandler.shutdown();
246	// Destroy our reference, leaving it for the GC
247	_dataHandler = null;
248	return true;
249	}
250	else {
251	return false;
252	}
253	}
254
255	/**
256	* Send an OK message to the outgoing Socket
257	*/
258	private void sendOK() {
259	send("OK");
260	}
261
262	/**
263	* Send an ERROR message to the outgoing Socket.
264	*/
265	private void sendERROR() {
266	send("ERROR");
267	}
268
269	/**
270	* Send any String message to the outgoing Socket.
271	*
272	* @param message The message/command to send.
273	*/
274	private void send(String message) {
275	_socketOut.println(message);
276	}
277
278	//---ACCESSOR/MUTATOR METHODS---
279
280	//---ATTRIBUTES---
281
282	/**
283	* This is the friendly identifier of the
284	* component this class is running in.
285	* eg, a Filter may be called "filter1",
286	* If this class does not have an owning
287	* component, a name from the configuration
288	* can be placed here. This name could also
289	* be changed to null for utility classes.
290	*/
291	private String _name = ClientInterfaceMain.NAME;
292
293	/**
294	* This holds a reference to the
295	* system logger that is being used.
296	*/
297	private Logger _logger = ReferenceManager.getInstance().getLogger();
298
299	/**
300	* A reference to the Configuration Manager the system is using
301	*/
302	private ConfigurationManager _configManager = ReferenceManager.getInstance().getCM();
303
304	/**
305	* The socket we are talking on
306	*/
307	private Socket _socket;
308
309	/**
310	* A hook to the inbound data from the socket
311	*/
312	private BufferedReader _socketIn;
313
314	/**
315	* A hook to the outbound stream for the socket
316	*/
317	private PrintWriter _socketOut;
318
319	/**
320	* A reference to the PacketSorter.
321	*/
322	private PacketSorter _packetSorter;
323
324	/**
325	* A reference to the DataHandler, if there is one
326	*/
327	private TCPDataHandler _dataHandler;
328
329	/**
330	* The name of the Client we're connected to
331	*/
332	private String _clientName;
333
334	/**
335	* The host list the Client has requested
336	*/
337	private String _hostList;
338
339	/**
340	* The interval at which to monitor our Queue
341	*/
342	private int _queueMonitorInterval;
343
344	//---STATIC ATTRIBUTES---
345
346	}