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.
#	User	Rev	Content
1	tdb	1.1	//---PACKAGE DECLARATION---
2	tdb	1.10	package uk.org.iscream.clientinterface;
3	tdb	1.1
4			//---IMPORTS---
5	tdb	1.10	import uk.org.iscream.util.*;
6			import uk.org.iscream.componentmanager.*;
7			import uk.org.iscream.core.*;
8			import uk.org.iscream.client.*;
9	tdb	1.1
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	1.11	* @version $Id: CorbaControlHandlerServant.java,v 1.10 2001/03/14 23:25:29 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	1.11	public final String REVISION = "$Revision: 1.10 $";
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	1.7	public CorbaControlHandlerServant(PacketSorter packetSorter, Client client, String clientname) {
42	tdb	1.1	_packetSorter = packetSorter;
43			_hostList = "";
44			_client = client;
45	tdb	1.6	_clientname = clientname;
46	tdb	1.3	_dataHandler = null;
47	tdb	1.1	_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	tdb	1.3	if(_dataHandler == null) {
59			// create a new DataHandler
60	tdb	1.11	CorbaDataHandler dh = new CorbaDataHandler(_client, this);
61	tdb	1.1	// register the Queue
62	tdb	1.3	_packetSorter.register(dh.getQueue(), _hostList);
63	tdb	1.7	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	tdb	1.3	// start the DataHandler running
73			dh.start();
74			// keep a reference
75			_dataHandler = dh;
76	tdb	1.1	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	tdb	1.3	if(_dataHandler != null) {
90	tdb	1.1	// deregister the Queue
91	tdb	1.3	_packetSorter.deregister(_dataHandler.getQueue(), _hostList);
92			// stop the DataHandler
93			_dataHandler.shutdown();
94			// destroy the reference
95			_dataHandler = null;
96	tdb	1.1	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	tdb	1.3	if(_dataHandler == null) {
112	tdb	1.1	_hostList = hostList;
113			return true;
114			}
115			else {
116			return false;
117			}
118			}
119
120			/**
121	tdb	1.8	* 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	tdb	1.9	byte[] oid = _refman.getRootPOA().servant_to_id(this);
130			_refman.getRootPOA().deactivate_object(oid);
131	tdb	1.8	} catch(Exception e) {
132			_logger.write(this.toString(), Logger.ERROR, "disconnect failed: "+e);
133			}
134			}
135
136			/**
137	tdb	1.1	* Overrides the {@link java.lang.Object#toString() Object.toString()}
138			* method to provide clean logging (every class should have this).
139			*
140	tdb	1.10	* This uses the uk.org.iscream.util.NameFormat class
141	tdb	1.1	* 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	tdb	1.8
175			/**
176			* A reference to the reference manager in use
177			*/
178			private ReferenceManager _refman = ReferenceManager.getInstance();
179	tdb	1.1
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	tdb	1.3	* A reference to our DataHandler, if we have one
197	tdb	1.1	*/
198	tdb	1.3	private CorbaDataHandler _dataHandler;
199	tdb	1.6
200			/**
201			* A name to identify the client
202			*/
203			private String _clientname;
204	tdb	1.1
205			//---STATIC ATTRIBUTES---
206
207			}