server/clientinterface/TCPDataHandler.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 java.net.Socket;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.PrintWriter;
import java.io.InputStreamReader;

/**
 * Acts as a Data Handler to a TCP based client, providing
 * it with a constant stream of XML data for the hosts the
 * client has requested.
 *
 * @author  $Author: tdb1 $
 * @version $Id: TCPDataHandler.java,v 1.10 2001/03/13 02:19:44 tdb1 Exp $
 */
class TCPDataHandler extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.10 $";
    
//---STATIC METHODS---

//---CONSTRUCTORS---
    
    /**
     * Construct a new TCPDataHandler with a Socket provided
     * by the Control Handler.
     *
     * @param socket The socket to which the Client has connected
     * @throws IOException if something goes wrong, the Control Handler can deal with it
     */
    public TCPDataHandler(Socket socket) throws IOException {
        // set the Thread name
        setName("clientinterface.TCPDataHandler");
        
        _socket = socket;
        _queue = new Queue();
        // setup the reader and writer
        _socketIn = new BufferedReader(new InputStreamReader(_socket.getInputStream()));
        _socketOut = new PrintWriter(_socket.getOutputStream(), true);
        _logger.write(toString(), Logger.SYSINIT, "created");
    }
    
//---PUBLIC METHODS---
    /**
     * Main loop for the Data Handler, keeps sending data from
     * it's local Queue.
     */
    public void run() {
        run = true;
        _queueID = _queue.getQueue();
        // run until we get told to stop
        while(run) {
            // get some data, and send some data
            try {
                String xml = (String) _queue.get(_queueID);
                // if we're shutting down and we've been "bumped"
                // it's likely we'll get a null back, and we don't
                // want to send that on to the Client
                if(xml != null) {
                    _socketOut.println(xml);
                }
            }
            catch(InvalidQueueException e) {
                run = false;
                _logger.write(toString(), Logger.ERROR, "Queue failure: "+e);
            }
        }
        // if we get here we've been told to stop
        _logger.write(toString(), Logger.SYSMSG, "Shutting Down");
        // shut down the reader, writer and Socket
        try {
            _socketOut.close();
            _socketIn.close();
            _socket.close();
        }
        catch(IOException e) {
            _logger.write(toString(), Logger.ERROR, "Exception whilst shutting down: "+e);
        }
        // remove ourselves from the queue
        _queue.removeQueue(_queueID);
        _queue.stopMonitor();
    }
    
    /**
     * Method to shutdown this Data Handler. All this actually does
     * is set a flag which the main loop will see and commence shutting
     * down. This method will return before the main loop stops.
     */
    public void shutdown() {
        // set the main loop to stop
        run=false;
        // if the main loop is waiting for data it won't notice the
        // above flag to stop. This bumps it out of the blocked get.
        _queue.releaseQueue(_queueID);
    }
    
    /**
     * 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---
    
    /**
     * Accessor to our Queue. The Control Handler needs to
     * get this reference to register us.
     *
     * @return a reference to our Queue
     */
    public Queue getQueue() {
        return _queue;
    }

//---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 hook to the inbound data from the socket
     */
    private BufferedReader _socketIn;
    
    /**
     * A hook to the outbound stream for the socket
     */
    private PrintWriter _socketOut;
    
    /**
     * A reference to the Socket connected to the client
     */
    private Socket _socket;
    
    /**
     * A reference to our Queue
     */
    private Queue _queue;
    
    /**
     * The flag that dictates whether we should be running
     */
    private boolean run;
    
    /**
     * Our queue number within our Queue
     */
    private int _queueID;
    
//---STATIC ATTRIBUTES---

}
Revision:	1.11
Committed:	Wed Mar 14 23:25:29 2001 UTC (23 years, 2 months ago) by tdb
Branch:	MAIN
Changes since 1.10:	+7 -7 lines
Log Message:	The whole server package structure has been changed. Old Package: uk.ac.ukc.iscream.* New Package: uk.org.iscream.*
#	User	Rev	Content
1	tdb	1.1	//---PACKAGE DECLARATION---
2	tdb	1.11	package uk.org.iscream.clientinterface;
3	tdb	1.1
4			//---IMPORTS---
5	tdb	1.11	import uk.org.iscream.util.*;
6			import uk.org.iscream.componentmanager.*;
7			import uk.org.iscream.core.*;
8	tdb	1.1	import java.net.Socket;
9			import java.io.InputStream;
10			import java.io.OutputStream;
11			import java.io.IOException;
12			import java.io.BufferedReader;
13			import java.io.PrintWriter;
14			import java.io.InputStreamReader;
15
16			/**
17	tdb	1.6	* Acts as a Data Handler to a TCP based client, providing
18			* it with a constant stream of XML data for the hosts the
19			* client has requested.
20	tdb	1.1	*
21	tdb	1.2	* @author $Author: tdb1 $
22	tdb	1.11	* @version $Id: TCPDataHandler.java,v 1.10 2001/03/13 02:19:44 tdb1 Exp $
23	tdb	1.1	*/
24	tdb	1.2	class TCPDataHandler extends Thread {
25	tdb	1.1
26			//---FINAL ATTRIBUTES---
27
28			/**
29			* The current CVS revision of this class
30			*/
31	tdb	1.11	public final String REVISION = "$Revision: 1.10 $";
32	tdb	1.1
33			//---STATIC METHODS---
34
35			//---CONSTRUCTORS---
36	tdb	1.6
37			/**
38			* Construct a new TCPDataHandler with a Socket provided
39			* by the Control Handler.
40			*
41			* @param socket The socket to which the Client has connected
42			* @throws IOException if something goes wrong, the Control Handler can deal with it
43			*/
44	tdb	1.4	public TCPDataHandler(Socket socket) throws IOException {
45	tdb	1.10	// set the Thread name
46			setName("clientinterface.TCPDataHandler");
47
48	tdb	1.1	_socket = socket;
49	tdb	1.4	_queue = new Queue();
50	tdb	1.6	// setup the reader and writer
51	tdb	1.1	_socketIn = new BufferedReader(new InputStreamReader(_socket.getInputStream()));
52	tdb	1.8	_socketOut = new PrintWriter(_socket.getOutputStream(), true);
53	tdb	1.1	_logger.write(toString(), Logger.SYSINIT, "created");
54			}
55
56			//---PUBLIC METHODS---
57	tdb	1.6	/**
58			* Main loop for the Data Handler, keeps sending data from
59			* it's local Queue.
60			*/
61	tdb	1.2	public void run() {
62			run = true;
63	tdb	1.5	_queueID = _queue.getQueue();
64	tdb	1.6	// run until we get told to stop
65	tdb	1.2	while(run) {
66	tdb	1.6	// get some data, and send some data
67	tdb	1.2	try {
68	tdb	1.5	String xml = (String) _queue.get(_queueID);
69	tdb	1.7	// if we're shutting down and we've been "bumped"
70			// it's likely we'll get a null back, and we don't
71			// want to send that on to the Client
72			if(xml != null) {
73			_socketOut.println(xml);
74			}
75	tdb	1.2	}
76			catch(InvalidQueueException e) {
77			run = false;
78			_logger.write(toString(), Logger.ERROR, "Queue failure: "+e);
79			}
80			}
81	tdb	1.6	// if we get here we've been told to stop
82	tdb	1.1	_logger.write(toString(), Logger.SYSMSG, "Shutting Down");
83	tdb	1.6	// shut down the reader, writer and Socket
84	tdb	1.2	try {
85			_socketOut.close();
86			_socketIn.close();
87			_socket.close();
88			}
89			catch(IOException e) {
90			_logger.write(toString(), Logger.ERROR, "Exception whilst shutting down: "+e);
91			}
92	tdb	1.6	// remove ourselves from the queue
93	tdb	1.5	_queue.removeQueue(_queueID);
94	tdb	1.9	_queue.stopMonitor();
95	tdb	1.2	}
96	tdb	1.6
97			/**
98			* Method to shutdown this Data Handler. All this actually does
99			* is set a flag which the main loop will see and commence shutting
100			* down. This method will return before the main loop stops.
101			*/
102	tdb	1.2	public void shutdown() {
103	tdb	1.6	// set the main loop to stop
104	tdb	1.2	run=false;
105	tdb	1.6	// if the main loop is waiting for data it won't notice the
106			// above flag to stop. This bumps it out of the blocked get.
107	tdb	1.5	_queue.releaseQueue(_queueID);
108	tdb	1.1	}
109
110			/**
111			* Overrides the {@link java.lang.Object#toString() Object.toString()}
112			* method to provide clean logging (every class should have this).
113			*
114	tdb	1.11	* This uses the uk.org.iscream.util.NameFormat class
115	tdb	1.1	* to format the toString()
116			*
117			* @return the name of this class and its CVS revision
118			*/
119			public String toString() {
120			return FormatName.getName(
121			_name,
122			getClass().getName(),
123			REVISION);
124			}
125
126			//---PRIVATE METHODS---
127
128			//---ACCESSOR/MUTATOR METHODS---
129	tdb	1.6
130			/**
131			* Accessor to our Queue. The Control Handler needs to
132			* get this reference to register us.
133			*
134			* @return a reference to our Queue
135			*/
136	tdb	1.4	public Queue getQueue() {
137			return _queue;
138			}
139
140	tdb	1.1	//---ATTRIBUTES---
141
142			/**
143			* This is the friendly identifier of the
144			* component this class is running in.
145			* eg, a Filter may be called "filter1",
146			* If this class does not have an owning
147			* component, a name from the configuration
148			* can be placed here. This name could also
149			* be changed to null for utility classes.
150			*/
151			private String _name = ClientInterfaceMain.NAME;
152
153			/**
154			* This holds a reference to the
155			* system logger that is being used.
156			*/
157			private Logger _logger = ReferenceManager.getInstance().getLogger();
158
159			/**
160			* A hook to the inbound data from the socket
161			*/
162			private BufferedReader _socketIn;
163
164			/**
165			* A hook to the outbound stream for the socket
166			*/
167			private PrintWriter _socketOut;
168
169	tdb	1.6	/**
170			* A reference to the Socket connected to the client
171			*/
172	tdb	1.1	private Socket _socket;
173	tdb	1.2
174	tdb	1.6	/**
175			* A reference to our Queue
176			*/
177	tdb	1.2	private Queue _queue;
178	tdb	1.6
179			/**
180			* The flag that dictates whether we should be running
181			*/
182	tdb	1.2	private boolean run;
183	tdb	1.6
184			/**
185			* Our queue number within our Queue
186			*/
187	tdb	1.5	private int _queueID;
188	tdb	1.1
189			//---STATIC ATTRIBUTES---
190
191			}