server/clientinterface/CorbaControlHandlerServant.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 uk.ac.ukc.iscream.client.*;


/**
 * Acts as a Control Handler to a CORBA based client.
 *
 * !!! FUNDAMENTAL DESIGN PROBLEM !!!
 * !!! Need a way to "shutdown" this class !!!
 *
 * @author  $Author: tdb1 $
 * @version $Id: CorbaControlHandlerServant.java,v 1.5 2001/02/21 19:11:28 tdb1 Exp $
 */
class CorbaControlHandlerServant extends CorbaControlHandlerPOA {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.5 $";
    
//---STATIC METHODS---

//---CONSTRUCTORS---
    
    /**
     * Construct a new CorbaControlHandlerServant.
     *
     * @param packetSorter A reference to the PacketSorter in the component
     * @param client A reference to the "servant" part of the connecting client.
     * @param queueMonitorInterval The interval at which to monitor our Queue.
     * @param clientname A name to identify the client.
     */
    public CorbaControlHandlerServant(PacketSorter packetSorter, Client client, int queueMonitorInterval, String clientname) {
        _packetSorter = packetSorter;
        _queueMonitorInterval = queueMonitorInterval;
        _hostList = "";
        _client = client;
        _clientname = clientname;
        _dataHandler = null;
        _logger.write(toString(), Logger.SYSINIT, "created");
    }
    
//---PUBLIC METHODS---
    
    /**
     * Start sending data to the client.
     *
     * @return a boolean stating whether the attempt to start succeeded
     */
    public boolean startData() {
        if(_dataHandler == null) {
            // create a new DataHandler
            CorbaDataHandler dh = new CorbaDataHandler(_client);
            // register the Queue
            _packetSorter.register(dh.getQueue(), _hostList);
            // startup a monitor on the DataHandler's queue, every minute
            String queueName = _name + " CorbaHandler:"+_clientname;
            dh.getQueue().startMonitor(_queueMonitorInterval*1000, _packetSorter.getQueue(), queueName);
            // start the DataHandler running
            dh.start();
            // keep a reference
            _dataHandler = dh;
            return true;
        }
        else {
            return false;
        }
    }
    
    /**
     * Stop sending data to the client.
     *
     * @return a boolean stating whether the attempt to stop succeeded
     */
    public boolean stopData() {
        if(_dataHandler != null) {
            // deregister the Queue
            _packetSorter.deregister(_dataHandler.getQueue(), _hostList);
            // stop the DataHandler
            _dataHandler.shutdown();
            // destroy the reference
            _dataHandler = null;
            return true;
        }
        else {
            return false;
        }
    }
    
    /**
     * Sets the host list for the Client to the requested semi-colon separated
     * list of hostnames. This will only succeed if we are not sending data.
     *
     * @param hostList A semi-colon separated list of hostnames to use.
     * @return Whether the request succeeded.
     */
    public boolean setHostList(String hostList) {
        if(_dataHandler == null) {
            _hostList = hostList;
            return true;
        }
        else {
            return false;
        }
    }
    
    /**
     * 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 PacketSorter.
         */
    private PacketSorter _packetSorter;
    
    /**
     * The host list the Client has requested
     */
    private String _hostList;
    
    /**
     * The "servant" part of the client we're connected to.
     */
    private Client _client;
    
    /**
     * A reference to our DataHandler, if we have one
     */
    private CorbaDataHandler _dataHandler;
    
    /**
     * The interval at which to monitor our Queue
     */
    private int _queueMonitorInterval;
    
    /**
     * A name to identify the client
     */
    private String _clientname;
    
//---STATIC ATTRIBUTES---

}
Revision:	1.6
Committed:	Wed Feb 28 19:04:00 2001 UTC (23 years, 2 months ago) by tdb
Branch:	MAIN
Changes since 1.5:	+11 -4 lines
Log Message:	Now requires a client send a name. This is to enable each handler to be identified from the others. With TCP ones, this was quite easily done with the hostname (which isn't perfect), but with corba a name was required.
#	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 uk.ac.ukc.iscream.client.*;
9
10
11			/**
12	tdb	1.3	* Acts as a Control Handler to a CORBA based client.
13	tdb	1.1	*
14			* !!! FUNDAMENTAL DESIGN PROBLEM !!!
15			* !!! Need a way to "shutdown" this class !!!
16			*
17	tdb	1.4	* @author $Author: tdb1 $
18	tdb	1.6	* @version $Id: CorbaControlHandlerServant.java,v 1.5 2001/02/21 19:11:28 tdb1 Exp $
19	tdb	1.1	*/
20	tdb	1.3	class CorbaControlHandlerServant extends CorbaControlHandlerPOA {
21	tdb	1.1
22			//---FINAL ATTRIBUTES---
23
24			/**
25			* The current CVS revision of this class
26			*/
27	tdb	1.6	public final String REVISION = "$Revision: 1.5 $";
28	tdb	1.1
29			//---STATIC METHODS---
30
31			//---CONSTRUCTORS---
32
33			/**
34	tdb	1.3	* Construct a new CorbaControlHandlerServant.
35	tdb	1.1	*
36			* @param packetSorter A reference to the PacketSorter in the component
37			* @param client A reference to the "servant" part of the connecting client.
38	tdb	1.5	* @param queueMonitorInterval The interval at which to monitor our Queue.
39	tdb	1.6	* @param clientname A name to identify the client.
40	tdb	1.1	*/
41	tdb	1.6	public CorbaControlHandlerServant(PacketSorter packetSorter, Client client, int queueMonitorInterval, String clientname) {
42	tdb	1.1	_packetSorter = packetSorter;
43	tdb	1.5	_queueMonitorInterval = queueMonitorInterval;
44	tdb	1.1	_hostList = "";
45			_client = client;
46	tdb	1.6	_clientname = clientname;
47	tdb	1.3	_dataHandler = null;
48	tdb	1.1	_logger.write(toString(), Logger.SYSINIT, "created");
49			}
50
51			//---PUBLIC METHODS---
52
53			/**
54			* Start sending data to the client.
55			*
56			* @return a boolean stating whether the attempt to start succeeded
57			*/
58			public boolean startData() {
59	tdb	1.3	if(_dataHandler == null) {
60			// create a new DataHandler
61			CorbaDataHandler dh = new CorbaDataHandler(_client);
62	tdb	1.1	// register the Queue
63	tdb	1.3	_packetSorter.register(dh.getQueue(), _hostList);
64	tdb	1.4	// startup a monitor on the DataHandler's queue, every minute
65	tdb	1.6	String queueName = _name + " CorbaHandler:"+_clientname;
66	tdb	1.5	dh.getQueue().startMonitor(_queueMonitorInterval*1000, _packetSorter.getQueue(), queueName);
67	tdb	1.3	// start the DataHandler running
68			dh.start();
69			// keep a reference
70			_dataHandler = dh;
71	tdb	1.1	return true;
72			}
73			else {
74			return false;
75			}
76			}
77
78			/**
79			* Stop sending data to the client.
80			*
81			* @return a boolean stating whether the attempt to stop succeeded
82			*/
83			public boolean stopData() {
84	tdb	1.3	if(_dataHandler != null) {
85	tdb	1.1	// deregister the Queue
86	tdb	1.3	_packetSorter.deregister(_dataHandler.getQueue(), _hostList);
87			// stop the DataHandler
88			_dataHandler.shutdown();
89			// destroy the reference
90			_dataHandler = null;
91	tdb	1.1	return true;
92			}
93			else {
94			return false;
95			}
96			}
97
98			/**
99			* Sets the host list for the Client to the requested semi-colon separated
100			* list of hostnames. This will only succeed if we are not sending data.
101			*
102			* @param hostList A semi-colon separated list of hostnames to use.
103			* @return Whether the request succeeded.
104			*/
105			public boolean setHostList(String hostList) {
106	tdb	1.3	if(_dataHandler == null) {
107	tdb	1.1	_hostList = hostList;
108			return true;
109			}
110			else {
111			return false;
112			}
113			}
114
115			/**
116			* Overrides the {@link java.lang.Object#toString() Object.toString()}
117			* method to provide clean logging (every class should have this).
118			*
119			* This uses the uk.ac.ukc.iscream.util.NameFormat class
120			* to format the toString()
121			*
122			* @return the name of this class and its CVS revision
123			*/
124			public String toString() {
125			return FormatName.getName(
126			_name,
127			getClass().getName(),
128			REVISION);
129			}
130
131			//---PRIVATE METHODS---
132
133			//---ACCESSOR/MUTATOR METHODS---
134
135			//---ATTRIBUTES---
136
137			/**
138			* This is the friendly identifier of the
139			* component this class is running in.
140			* eg, a Filter may be called "filter1",
141			* If this class does not have an owning
142			* component, a name from the configuration
143			* can be placed here. This name could also
144			* be changed to null for utility classes.
145			*/
146			private String _name = ClientInterfaceMain.NAME;
147
148			/**
149			* This holds a reference to the
150			* system logger that is being used.
151			*/
152			private Logger _logger = ReferenceManager.getInstance().getLogger();
153
154			/**
155			* A reference to the PacketSorter.
156			*/
157			private PacketSorter _packetSorter;
158
159			/**
160			* The host list the Client has requested
161			*/
162			private String _hostList;
163
164			/**
165			* The "servant" part of the client we're connected to.
166			*/
167			private Client _client;
168
169			/**
170	tdb	1.3	* A reference to our DataHandler, if we have one
171	tdb	1.1	*/
172	tdb	1.3	private CorbaDataHandler _dataHandler;
173	tdb	1.5
174			/**
175			* The interval at which to monitor our Queue
176			*/
177			private int _queueMonitorInterval;
178	tdb	1.6
179			/**
180			* A name to identify the client
181			*/
182			private String _clientname;
183	tdb	1.1
184			//---STATIC ATTRIBUTES---
185
186			}