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 1.4 2001/02/12 02:23:52 tdb1 Exp $
 */
class CorbaControlHandlerServant extends CorbaControlHandlerPOA {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.4 $";
    
//---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.
     */
    public CorbaControlHandlerServant(PacketSorter packetSorter, Client client, int queueMonitorInterval) {
        _packetSorter = packetSorter;
        _queueMonitorInterval = queueMonitorInterval;
        _hostList = "";
        _client = client;
        _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";
            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;
    
//---STATIC ATTRIBUTES---

}
Revision:	1.5
Committed:	Wed Feb 21 19:11:28 2001 UTC (23 years, 3 months ago) by tdb
Branch:	MAIN
Changes since 1.4:	+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.
#	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	1.5	* @version $Id: CorbaControlHandlerServant.java,v 1.4 2001/02/12 02:23:52 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	1.5	public final String REVISION = "$Revision: 1.4 $";
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	1.1	*/
40	tdb	1.5	public CorbaControlHandlerServant(PacketSorter packetSorter, Client client, int queueMonitorInterval) {
41	tdb	1.1	_packetSorter = packetSorter;
42	tdb	1.5	_queueMonitorInterval = queueMonitorInterval;
43	tdb	1.1	_hostList = "";
44			_client = client;
45	tdb	1.3	_dataHandler = null;
46	tdb	1.1	_logger.write(toString(), Logger.SYSINIT, "created");
47			}
48
49			//---PUBLIC METHODS---
50
51			/**
52			* Start sending data to the client.
53			*
54			* @return a boolean stating whether the attempt to start succeeded
55			*/
56			public boolean startData() {
57	tdb	1.3	if(_dataHandler == null) {
58			// create a new DataHandler
59			CorbaDataHandler dh = new CorbaDataHandler(_client);
60	tdb	1.1	// register the Queue
61	tdb	1.3	_packetSorter.register(dh.getQueue(), _hostList);
62	tdb	1.4	// startup a monitor on the DataHandler's queue, every minute
63	tdb	1.5	String queueName = _name + " CorbaHandler";
64			dh.getQueue().startMonitor(_queueMonitorInterval*1000, _packetSorter.getQueue(), queueName);
65	tdb	1.3	// start the DataHandler running
66			dh.start();
67			// keep a reference
68			_dataHandler = dh;
69	tdb	1.1	return true;
70			}
71			else {
72			return false;
73			}
74			}
75
76			/**
77			* Stop sending data to the client.
78			*
79			* @return a boolean stating whether the attempt to stop succeeded
80			*/
81			public boolean stopData() {
82	tdb	1.3	if(_dataHandler != null) {
83	tdb	1.1	// deregister the Queue
84	tdb	1.3	_packetSorter.deregister(_dataHandler.getQueue(), _hostList);
85			// stop the DataHandler
86			_dataHandler.shutdown();
87			// destroy the reference
88			_dataHandler = null;
89	tdb	1.1	return true;
90			}
91			else {
92			return false;
93			}
94			}
95
96			/**
97			* Sets the host list for the Client to the requested semi-colon separated
98			* list of hostnames. This will only succeed if we are not sending data.
99			*
100			* @param hostList A semi-colon separated list of hostnames to use.
101			* @return Whether the request succeeded.
102			*/
103			public boolean setHostList(String hostList) {
104	tdb	1.3	if(_dataHandler == null) {
105	tdb	1.1	_hostList = hostList;
106			return true;
107			}
108			else {
109			return false;
110			}
111			}
112
113			/**
114			* Overrides the {@link java.lang.Object#toString() Object.toString()}
115			* method to provide clean logging (every class should have this).
116			*
117			* This uses the uk.ac.ukc.iscream.util.NameFormat class
118			* to format the toString()
119			*
120			* @return the name of this class and its CVS revision
121			*/
122			public String toString() {
123			return FormatName.getName(
124			_name,
125			getClass().getName(),
126			REVISION);
127			}
128
129			//---PRIVATE METHODS---
130
131			//---ACCESSOR/MUTATOR METHODS---
132
133			//---ATTRIBUTES---
134
135			/**
136			* This is the friendly identifier of the
137			* component this class is running in.
138			* eg, a Filter may be called "filter1",
139			* If this class does not have an owning
140			* component, a name from the configuration
141			* can be placed here. This name could also
142			* be changed to null for utility classes.
143			*/
144			private String _name = ClientInterfaceMain.NAME;
145
146			/**
147			* This holds a reference to the
148			* system logger that is being used.
149			*/
150			private Logger _logger = ReferenceManager.getInstance().getLogger();
151
152			/**
153			* A reference to the PacketSorter.
154			*/
155			private PacketSorter _packetSorter;
156
157			/**
158			* The host list the Client has requested
159			*/
160			private String _hostList;
161
162			/**
163			* The "servant" part of the client we're connected to.
164			*/
165			private Client _client;
166
167			/**
168	tdb	1.3	* A reference to our DataHandler, if we have one
169	tdb	1.1	*/
170	tdb	1.3	private CorbaDataHandler _dataHandler;
171	tdb	1.5
172			/**
173			* The interval at which to monitor our Queue
174			*/
175			private int _queueMonitorInterval;
176	tdb	1.1
177			//---STATIC ATTRIBUTES---
178
179			}