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.
#	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 uk.ac.ukc.iscream.client.*;
9
10
11	/**
12	* Acts as a Control Handler to a CORBA based client.
13	*
14	* !!! FUNDAMENTAL DESIGN PROBLEM !!!
15	* !!! Need a way to "shutdown" this class !!!
16	*
17	* @author $Author: tdb1 $
18	* @version $Id: CorbaControlHandlerServant.java,v 1.5 2001/02/21 19:11:28 tdb1 Exp $
19	*/
20	class CorbaControlHandlerServant extends CorbaControlHandlerPOA {
21
22	//---FINAL ATTRIBUTES---
23
24	/**
25	* The current CVS revision of this class
26	*/
27	public final String REVISION = "$Revision: 1.5 $";
28
29	//---STATIC METHODS---
30
31	//---CONSTRUCTORS---
32
33	/**
34	* Construct a new CorbaControlHandlerServant.
35	*
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	* @param queueMonitorInterval The interval at which to monitor our Queue.
39	* @param clientname A name to identify the client.
40	*/
41	public CorbaControlHandlerServant(PacketSorter packetSorter, Client client, int queueMonitorInterval, String clientname) {
42	_packetSorter = packetSorter;
43	_queueMonitorInterval = queueMonitorInterval;
44	_hostList = "";
45	_client = client;
46	_clientname = clientname;
47	_dataHandler = null;
48	_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	if(_dataHandler == null) {
60	// create a new DataHandler
61	CorbaDataHandler dh = new CorbaDataHandler(_client);
62	// register the Queue
63	_packetSorter.register(dh.getQueue(), _hostList);
64	// startup a monitor on the DataHandler's queue, every minute
65	String queueName = _name + " CorbaHandler:"+_clientname;
66	dh.getQueue().startMonitor(_queueMonitorInterval*1000, _packetSorter.getQueue(), queueName);
67	// start the DataHandler running
68	dh.start();
69	// keep a reference
70	_dataHandler = dh;
71	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	if(_dataHandler != null) {
85	// deregister the Queue
86	_packetSorter.deregister(_dataHandler.getQueue(), _hostList);
87	// stop the DataHandler
88	_dataHandler.shutdown();
89	// destroy the reference
90	_dataHandler = null;
91	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	if(_dataHandler == null) {
107	_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	* A reference to our DataHandler, if we have one
171	*/
172	private CorbaDataHandler _dataHandler;
173
174	/**
175	* The interval at which to monitor our Queue
176	*/
177	private int _queueMonitorInterval;
178
179	/**
180	* A name to identify the client
181	*/
182	private String _clientname;
183
184	//---STATIC ATTRIBUTES---
185
186	}