server/filter/UDPReader.java

//---PACKAGE DECLARATION---
package uk.org.iscream.cms.server.filter;

//---IMPORTS---
import java.io.*;
import java.net.*;
import java.util.*;
import uk.org.iscream.cms.server.core.*;
import uk.org.iscream.cms.server.componentmanager.*;
import uk.org.iscream.cms.server.filter.*;
import uk.org.iscream.cms.server.util.*;

/**
 * This class contains the main method to be run by
 * the filterd.  It harvests UDP traffic, and queues it.
 *
 * @author  $Author: tdb1 $
 * @version $Id: UDPReader.java,v 1.17 2001/03/14 23:25:29 tdb1 Exp $
 */
public class UDPReader extends Thread{

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.17 $";
    
    /**
     * The maximum size of a packet
     */
    private final int packetSizeLimit = 8192;   
    
//---STATIC METHODS---

//---CONSTRUCTORS---

    /**
     * Constructs a new UDPReader.
     *
     * @param port The port on which we listen for UDP data
     * @param queue The queue which we are using
     */
    public UDPReader(int port, Queue queue){
        // set the Thread name
        setName("filter.UDPReader");
        
        _port = port;
        _queue = queue;
        _logger.write(toString(), Logger.SYSINIT, "started");
    }

//---PUBLIC METHODS---
    
    /**
     * The main method in the class. Reads and queues XML sent
     * over UDP.
     */
    public void run() {
        
        // setup a Datagram socket
        DatagramSocket socket = null;
        try {
            socket = new DatagramSocket(_port);
        }
        catch (BindException e){
            _logger.write(this.toString(), Logger.FATAL, "Could not start the UDPReader thread on port "+_port+" as this port was already in use.");
            return;
        }
        catch (Exception e){
            _logger.write(this.toString(), Logger.FATAL, "Could not start the UDPReader thread on port "+_port+".");
            return;
        }
        
        _logger.write(this.toString(), Logger.SYSMSG, "UDPReader thread ready and listening for UDP packets on port "+_port);
        
        byte[] buf;
        
        // read UDP packets and queue them
        boolean running = true;
        while (running){
            try {
                
                // receive request and put it in the Queue               
                buf = new byte[packetSizeLimit];
                DatagramPacket packet = new DatagramPacket(buf, buf.length);
                socket.receive(packet);
                String xml = new String(packet.getData());
                _queue.add(xml);
            }
            catch (IOException e) {
                _logger.write(this.toString(), Logger.WARNING, "This UDPReader thread has been shut down as an exception occured: "+e);
                running = false;
            }
        }
        socket.close();
    }
    
    /**
     * 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.cms.server.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 = FilterMain.NAME;
    
    /**
     * This holds a reference to the
     * system logger that is being used.
     */
    private Logger _logger = ReferenceManager.getInstance().getLogger();
    
    /**
     * The port that this reader is using
     */
    int _port;
    
    /**
     * The Queue object
     */
    Queue _queue;

//---STATIC ATTRIBUTES---

}
Revision:	1.18
Committed:	Tue May 29 17:02:35 2001 UTC (22 years, 11 months ago) by tdb
Branch:	MAIN
Branch point for:	SERVER_PIRCBOT
Changes since 1.17:	+8 -8 lines
Log Message:	Major change in the java package naming. This has been held off for some time now, but it really needed doing. The future packaging of all i-scream products will be; uk.org.iscream.<product>.<subpart>.* In the case of the central monitoring system server this will be; uk.org.iscream.cms.server.* The whole server has been changed to follow this structure, and tested to a smallish extent. Further changes in other parts of the CMS will follow.
#	User	Rev	Content
1	tdb	1.6	//---PACKAGE DECLARATION---
2	tdb	1.18	package uk.org.iscream.cms.server.filter;
3	tdb	1.6
4			//---IMPORTS---
5	pjm2	1.1	import java.io.*;
6			import java.net.*;
7			import java.util.*;
8	tdb	1.18	import uk.org.iscream.cms.server.core.*;
9			import uk.org.iscream.cms.server.componentmanager.*;
10			import uk.org.iscream.cms.server.filter.*;
11			import uk.org.iscream.cms.server.util.*;
12	pjm2	1.1
13	tdb	1.6	/**
14			* This class contains the main method to be run by
15	tdb	1.14	* the filterd. It harvests UDP traffic, and queues it.
16	tdb	1.6	*
17	tdb	1.13	* @author $Author: tdb1 $
18	tdb	1.18	* @version $Id: UDPReader.java,v 1.17 2001/03/14 23:25:29 tdb1 Exp $
19	tdb	1.6	*/
20	pjm2	1.1	public class UDPReader extends Thread{
21
22	tdb	1.6	//---FINAL ATTRIBUTES---
23
24			/**
25			* The current CVS revision of this class
26			*/
27	tdb	1.18	public final String REVISION = "$Revision: 1.17 $";
28	tdb	1.15
29	ajm	1.11	/**
30			* The maximum size of a packet
31			*/
32			private final int packetSizeLimit = 8192;
33	tdb	1.6
34			//---STATIC METHODS---
35
36			//---CONSTRUCTORS---
37
38	ajm	1.10	/**
39	tdb	1.14	* Constructs a new UDPReader.
40			*
41			* @param port The port on which we listen for UDP data
42			* @param queue The queue which we are using
43	ajm	1.10	*/
44	tdb	1.12	public UDPReader(int port, Queue queue){
45	tdb	1.16	// set the Thread name
46			setName("filter.UDPReader");
47
48	tdb	1.8	_port = port;
49	tdb	1.12	_queue = queue;
50	tdb	1.15	_logger.write(toString(), Logger.SYSINIT, "started");
51	pjm2	1.1	}
52
53	tdb	1.6	//---PUBLIC METHODS---
54	tdb	1.14
55			/**
56			* The main method in the class. Reads and queues XML sent
57			* over UDP.
58			*/
59	pjm2	1.1	public void run() {
60	tdb	1.14
61			// setup a Datagram socket
62	pjm2	1.1	DatagramSocket socket = null;
63			try {
64	tdb	1.8	socket = new DatagramSocket(_port);
65	pjm2	1.1	}
66			catch (BindException e){
67	tdb	1.8	_logger.write(this.toString(), Logger.FATAL, "Could not start the UDPReader thread on port "+_port+" as this port was already in use.");
68	pjm2	1.1	return;
69			}
70			catch (Exception e){
71	tdb	1.8	_logger.write(this.toString(), Logger.FATAL, "Could not start the UDPReader thread on port "+_port+".");
72	pjm2	1.1	return;
73			}
74
75	tdb	1.8	_logger.write(this.toString(), Logger.SYSMSG, "UDPReader thread ready and listening for UDP packets on port "+_port);
76	tdb	1.15
77	pjm2	1.1	byte[] buf;
78
79	tdb	1.14	// read UDP packets and queue them
80	pjm2	1.1	boolean running = true;
81			while (running){
82			try {
83	tdb	1.15
84			// receive request and put it in the Queue
85	pjm2	1.1	buf = new byte[packetSizeLimit];
86			DatagramPacket packet = new DatagramPacket(buf, buf.length);
87			socket.receive(packet);
88	tdb	1.12	String xml = new String(packet.getData());
89			_queue.add(xml);
90	pjm2	1.1	}
91			catch (IOException e) {
92	tdb	1.8	_logger.write(this.toString(), Logger.WARNING, "This UDPReader thread has been shut down as an exception occured: "+e);
93	tdb	1.14	running = false;
94	pjm2	1.1	}
95			}
96			socket.close();
97			}
98	tdb	1.15
99	tdb	1.6	/**
100			* Overrides the {@link java.lang.Object#toString() Object.toString()}
101			* method to provide clean logging (every class should have this).
102			*
103	tdb	1.18	* This uses the uk.org.iscream.cms.server.util.NameFormat class
104	ajm	1.11	* to format the toString()
105			*
106	tdb	1.6	* @return the name of this class and its CVS revision
107			*/
108			public String toString() {
109	ajm	1.11	return FormatName.getName(
110			_name,
111			getClass().getName(),
112			REVISION);
113	tdb	1.6	}
114
115			//---PRIVATE METHODS---
116
117			//---ACCESSOR/MUTATOR METHODS---
118
119			//---ATTRIBUTES---
120
121	ajm	1.11	/**
122			* This is the friendly identifier of the
123			* component this class is running in.
124			* eg, a Filter may be called "filter1",
125			* If this class does not have an owning
126			* component, a name from the configuration
127			* can be placed here. This name could also
128			* be changed to null for utility classes.
129			*/
130			private String _name = FilterMain.NAME;
131	tdb	1.15
132	ajm	1.11	/**
133			* This holds a reference to the
134			* system logger that is being used.
135			*/
136			private Logger _logger = ReferenceManager.getInstance().getLogger();
137
138			/**
139			* The port that this reader is using
140			*/
141	tdb	1.8	int _port;
142	ajm	1.11
143			/**
144	tdb	1.12	* The Queue object
145	ajm	1.11	*/
146	tdb	1.15	Queue _queue;
147	tdb	1.6
148			//---STATIC ATTRIBUTES---
149
150	pjm2	1.1	}