server/clientinterface/CorbaControlHandlerServant.java

//---PACKAGE DECLARATION---
package uk.org.iscream.clientinterface;

//---IMPORTS---
import uk.org.iscream.util.*;
import uk.org.iscream.componentmanager.*;
import uk.org.iscream.core.*;
import uk.org.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 1.10 2001/03/14 23:25:29 tdb1 Exp $
 */
class CorbaControlHandlerServant extends CorbaControlHandlerPOA {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.10 $";
    
//---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, String clientname) {
        _packetSorter = packetSorter;
        _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, this);
            // register the Queue
            _packetSorter.register(dh.getQueue(), _hostList);
            try {
                // startup a monitor on the DataHandler's queue
                ConfigurationProxy cp = ConfigurationProxy.getInstance();
                int queueMonitorInterval = Integer.parseInt(cp.getProperty("ClientInterface", "Queue.MonitorInterval"));
                String queueName = _name + " CorbaHandler:"+_clientname;
                dh.getQueue().startMonitor(queueMonitorInterval*1000, _packetSorter.getQueue(), queueName);
            } catch (PropertyNotFoundException e) {
                _logger.write(toString(), Logger.WARNING, "failed to find queue monitor config, disabling. " + e);
            }
            // 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;
        }
    }
    
    /**
     * Disconnect, this will shutdown the data and unhook from
     * the CORBA ORB.
     */
    public void disconnect() {
        // close the data handler
        stopData();
        // disconnect from the ORB
        try {
            byte[] oid = _refman.getRootPOA().servant_to_id(this);
            _refman.getRootPOA().deactivate_object(oid);
        } catch(Exception e) {
            _logger.write(this.toString(), Logger.ERROR, "disconnect failed: "+e);
        }
    }
    
    /**
     * Overrides the {@link java.lang.Object#toString() Object.toString()}
     * method to provide clean logging (every class should have this).
     *
     * This uses the uk.org.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 reference manager in use
     */
    private ReferenceManager _refman = ReferenceManager.getInstance();
    
    /**
         * 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;
    
    /**
     * A name to identify the client
     */
    private String _clientname;
    
//---STATIC ATTRIBUTES---

}
Revision:	1.11
Committed:	Fri Mar 16 01:50:36 2001 UTC (23 years, 2 months ago) by tdb
Branch:	MAIN
Changes since 1.10:	+3 -3 lines
Log Message:	When a CORBA Client disconnects it is caught in the DataHandler. But this would leave the ControlHandler just lurking about, so we now explicitly make an effort to close it down, and disconnect it from the ORB.
#	Content
1	//---PACKAGE DECLARATION---
2	package uk.org.iscream.clientinterface;
3
4	//---IMPORTS---
5	import uk.org.iscream.util.*;
6	import uk.org.iscream.componentmanager.*;
7	import uk.org.iscream.core.*;
8	import uk.org.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 1.10 2001/03/14 23:25:29 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: 1.10 $";
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, String clientname) {
42	_packetSorter = packetSorter;
43	_hostList = "";
44	_client = client;
45	_clientname = clientname;
46	_dataHandler = null;
47	_logger.write(toString(), Logger.SYSINIT, "created");
48	}
49
50	//---PUBLIC METHODS---
51
52	/**
53	* Start sending data to the client.
54	*
55	* @return a boolean stating whether the attempt to start succeeded
56	*/
57	public boolean startData() {
58	if(_dataHandler == null) {
59	// create a new DataHandler
60	CorbaDataHandler dh = new CorbaDataHandler(_client, this);
61	// register the Queue
62	_packetSorter.register(dh.getQueue(), _hostList);
63	try {
64	// startup a monitor on the DataHandler's queue
65	ConfigurationProxy cp = ConfigurationProxy.getInstance();
66	int queueMonitorInterval = Integer.parseInt(cp.getProperty("ClientInterface", "Queue.MonitorInterval"));
67	String queueName = _name + " CorbaHandler:"+_clientname;
68	dh.getQueue().startMonitor(queueMonitorInterval*1000, _packetSorter.getQueue(), queueName);
69	} catch (PropertyNotFoundException e) {
70	_logger.write(toString(), Logger.WARNING, "failed to find queue monitor config, disabling. " + e);
71	}
72	// start the DataHandler running
73	dh.start();
74	// keep a reference
75	_dataHandler = dh;
76	return true;
77	}
78	else {
79	return false;
80	}
81	}
82
83	/**
84	* Stop sending data to the client.
85	*
86	* @return a boolean stating whether the attempt to stop succeeded
87	*/
88	public boolean stopData() {
89	if(_dataHandler != null) {
90	// deregister the Queue
91	_packetSorter.deregister(_dataHandler.getQueue(), _hostList);
92	// stop the DataHandler
93	_dataHandler.shutdown();
94	// destroy the reference
95	_dataHandler = null;
96	return true;
97	}
98	else {
99	return false;
100	}
101	}
102
103	/**
104	* Sets the host list for the Client to the requested semi-colon separated
105	* list of hostnames. This will only succeed if we are not sending data.
106	*
107	* @param hostList A semi-colon separated list of hostnames to use.
108	* @return Whether the request succeeded.
109	*/
110	public boolean setHostList(String hostList) {
111	if(_dataHandler == null) {
112	_hostList = hostList;
113	return true;
114	}
115	else {
116	return false;
117	}
118	}
119
120	/**
121	* Disconnect, this will shutdown the data and unhook from
122	* the CORBA ORB.
123	*/
124	public void disconnect() {
125	// close the data handler
126	stopData();
127	// disconnect from the ORB
128	try {
129	byte[] oid = _refman.getRootPOA().servant_to_id(this);
130	_refman.getRootPOA().deactivate_object(oid);
131	} catch(Exception e) {
132	_logger.write(this.toString(), Logger.ERROR, "disconnect failed: "+e);
133	}
134	}
135
136	/**
137	* Overrides the {@link java.lang.Object#toString() Object.toString()}
138	* method to provide clean logging (every class should have this).
139	*
140	* This uses the uk.org.iscream.util.NameFormat class
141	* to format the toString()
142	*
143	* @return the name of this class and its CVS revision
144	*/
145	public String toString() {
146	return FormatName.getName(
147	_name,
148	getClass().getName(),
149	REVISION);
150	}
151
152	//---PRIVATE METHODS---
153
154	//---ACCESSOR/MUTATOR METHODS---
155
156	//---ATTRIBUTES---
157
158	/**
159	* This is the friendly identifier of the
160	* component this class is running in.
161	* eg, a Filter may be called "filter1",
162	* If this class does not have an owning
163	* component, a name from the configuration
164	* can be placed here. This name could also
165	* be changed to null for utility classes.
166	*/
167	private String _name = ClientInterfaceMain.NAME;
168
169	/**
170	* This holds a reference to the
171	* system logger that is being used.
172	*/
173	private Logger _logger = ReferenceManager.getInstance().getLogger();
174
175	/**
176	* A reference to the reference manager in use
177	*/
178	private ReferenceManager _refman = ReferenceManager.getInstance();
179
180	/**
181	* A reference to the PacketSorter.
182	*/
183	private PacketSorter _packetSorter;
184
185	/**
186	* The host list the Client has requested
187	*/
188	private String _hostList;
189
190	/**
191	* The "servant" part of the client we're connected to.
192	*/
193	private Client _client;
194
195	/**
196	* A reference to our DataHandler, if we have one
197	*/
198	private CorbaDataHandler _dataHandler;
199
200	/**
201	* A name to identify the client
202	*/
203	private String _clientname;
204
205	//---STATIC ATTRIBUTES---
206
207	}