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  $Author$
 * @version $Id$
 */
class CorbaControlHandlerServant extends CorbaControlHandlerPOA {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.2 $";
    
//---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.
     */
    public CorbaControlHandlerServant(PacketSorter packetSorter, Client client) {
        _packetSorter = packetSorter;
        _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);
            // 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;
    
//---STATIC ATTRIBUTES---

}
Revision:	1.3
Committed:	Mon Feb 5 00:58:46 2001 UTC (23 years, 3 months ago) by tdb
Branch:	MAIN
Changes since 1.2:	+25 -94 lines
Log Message:	The original "all in one" class didn't work quite right, so it's been broken down into two classes; one for control, and one for sending data. The whole lot functions in a very similar way to the TCP setup, except that communication happens over CORBA.
#	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 $Author$
18	* @version $Id$
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: 1.2 $";
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	*/
39	public CorbaControlHandlerServant(PacketSorter packetSorter, Client client) {
40	_packetSorter = packetSorter;
41	_hostList = "";
42	_client = client;
43	_dataHandler = null;
44	_logger.write(toString(), Logger.SYSINIT, "created");
45	}
46
47	//---PUBLIC METHODS---
48
49	/**
50	* Start sending data to the client.
51	*
52	* @return a boolean stating whether the attempt to start succeeded
53	*/
54	public boolean startData() {
55	if(_dataHandler == null) {
56	// create a new DataHandler
57	CorbaDataHandler dh = new CorbaDataHandler(_client);
58	// register the Queue
59	_packetSorter.register(dh.getQueue(), _hostList);
60	// start the DataHandler running
61	dh.start();
62	// keep a reference
63	_dataHandler = dh;
64	return true;
65	}
66	else {
67	return false;
68	}
69	}
70
71	/**
72	* Stop sending data to the client.
73	*
74	* @return a boolean stating whether the attempt to stop succeeded
75	*/
76	public boolean stopData() {
77	if(_dataHandler != null) {
78	// deregister the Queue
79	_packetSorter.deregister(_dataHandler.getQueue(), _hostList);
80	// stop the DataHandler
81	_dataHandler.shutdown();
82	// destroy the reference
83	_dataHandler = null;
84	return true;
85	}
86	else {
87	return false;
88	}
89	}
90
91	/**
92	* Sets the host list for the Client to the requested semi-colon separated
93	* list of hostnames. This will only succeed if we are not sending data.
94	*
95	* @param hostList A semi-colon separated list of hostnames to use.
96	* @return Whether the request succeeded.
97	*/
98	public boolean setHostList(String hostList) {
99	if(_dataHandler == null) {
100	_hostList = hostList;
101	return true;
102	}
103	else {
104	return false;
105	}
106	}
107
108	/**
109	* Overrides the {@link java.lang.Object#toString() Object.toString()}
110	* method to provide clean logging (every class should have this).
111	*
112	* This uses the uk.ac.ukc.iscream.util.NameFormat class
113	* to format the toString()
114	*
115	* @return the name of this class and its CVS revision
116	*/
117	public String toString() {
118	return FormatName.getName(
119	_name,
120	getClass().getName(),
121	REVISION);
122	}
123
124	//---PRIVATE METHODS---
125
126	//---ACCESSOR/MUTATOR METHODS---
127
128	//---ATTRIBUTES---
129
130	/**
131	* This is the friendly identifier of the
132	* component this class is running in.
133	* eg, a Filter may be called "filter1",
134	* If this class does not have an owning
135	* component, a name from the configuration
136	* can be placed here. This name could also
137	* be changed to null for utility classes.
138	*/
139	private String _name = ClientInterfaceMain.NAME;
140
141	/**
142	* This holds a reference to the
143	* system logger that is being used.
144	*/
145	private Logger _logger = ReferenceManager.getInstance().getLogger();
146
147	/**
148	* A reference to the PacketSorter.
149	*/
150	private PacketSorter _packetSorter;
151
152	/**
153	* The host list the Client has requested
154	*/
155	private String _hostList;
156
157	/**
158	* The "servant" part of the client we're connected to.
159	*/
160	private Client _client;
161
162	/**
163	* A reference to our DataHandler, if we have one
164	*/
165	private CorbaDataHandler _dataHandler;
166
167	//---STATIC ATTRIBUTES---
168
169	}