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: tdb $
 * @version $Id: UDPReader.java,v 1.20 2002/03/20 12:56:37 tdb Exp $
 */
public class UDPReader extends Thread{

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.20 $";
    
    /**
     * 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() {
        // get our ACL from the configuration
        ACL acl = null;
        try {
            String stringACL = ConfigurationProxy.getInstance().getProperty("Filter." + FilterMain.NAME, "Filter.UDPACL");
            acl = new ACL(stringACL);
        }
        catch(PropertyNotFoundException e) {
            _logger.write(toString(), Logger.WARNING, "No ACL found for UDPReader: " + e);
        }
        
        // setup a Datagram socket
        DatagramSocket socket = null;
        try {
            // use an ACLServerSocket if we have an ACL
                        if(acl != null) {
                            socket = new ACLDatagramSocket(acl, _port);
                        }
                        else {
                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:	1.21
Committed:	Wed Mar 20 13:05:50 2002 UTC (22 years, 2 months ago) by tdb
Branch:	MAIN
Changes since 1.20:	+3 -3 lines
Log Message:	Filter will now request the config "Filter.<name>", as opposed to just "<name>" which it did before. The documentation suggests it should do what it does now, and this seems the most sane thing to do.
#	Content
1	//---PACKAGE DECLARATION---
2	package uk.org.iscream.cms.server.filter;
3
4	//---IMPORTS---
5	import java.io.*;
6	import java.net.*;
7	import java.util.*;
8	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
13	/**
14	* This class contains the main method to be run by
15	* the filterd. It harvests UDP traffic, and queues it.
16	*
17	* @author $Author: tdb $
18	* @version $Id: UDPReader.java,v 1.20 2002/03/20 12:56:37 tdb Exp $
19	*/
20	public class UDPReader extends Thread{
21
22	//---FINAL ATTRIBUTES---
23
24	/**
25	* The current CVS revision of this class
26	*/
27	public final String REVISION = "$Revision: 1.20 $";
28
29	/**
30	* The maximum size of a packet
31	*/
32	private final int packetSizeLimit = 8192;
33
34	//---STATIC METHODS---
35
36	//---CONSTRUCTORS---
37
38	/**
39	* 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	*/
44	public UDPReader(int port, Queue queue){
45	// set the Thread name
46	setName("filter.UDPReader");
47
48	_port = port;
49	_queue = queue;
50	_logger.write(toString(), Logger.SYSINIT, "started");
51	}
52
53	//---PUBLIC METHODS---
54
55	/**
56	* The main method in the class. Reads and queues XML sent
57	* over UDP.
58	*/
59	public void run() {
60	// get our ACL from the configuration
61	ACL acl = null;
62	try {
63	String stringACL = ConfigurationProxy.getInstance().getProperty("Filter." + FilterMain.NAME, "Filter.UDPACL");
64	acl = new ACL(stringACL);
65	}
66	catch(PropertyNotFoundException e) {
67	_logger.write(toString(), Logger.WARNING, "No ACL found for UDPReader: " + e);
68	}
69
70	// setup a Datagram socket
71	DatagramSocket socket = null;
72	try {
73	// use an ACLServerSocket if we have an ACL
74	if(acl != null) {
75	socket = new ACLDatagramSocket(acl, _port);
76	}
77	else {
78	socket = new DatagramSocket(_port);
79	}
80	}
81	catch (BindException e){
82	_logger.write(this.toString(), Logger.FATAL, "Could not start the UDPReader thread on port "+_port+" as this port was already in use.");
83	return;
84	}
85	catch (Exception e){
86	_logger.write(this.toString(), Logger.FATAL, "Could not start the UDPReader thread on port "+_port+".");
87	return;
88	}
89
90	_logger.write(this.toString(), Logger.SYSMSG, "UDPReader thread ready and listening for UDP packets on port "+_port);
91
92	byte[] buf;
93
94	// read UDP packets and queue them
95	boolean running = true;
96	while (running){
97	try {
98
99	// receive request and put it in the Queue
100	buf = new byte[packetSizeLimit];
101	DatagramPacket packet = new DatagramPacket(buf, buf.length);
102	socket.receive(packet);
103	String xml = new String(packet.getData());
104	_queue.add(xml);
105	}
106	catch (IOException e) {
107	_logger.write(this.toString(), Logger.WARNING, "This UDPReader thread has been shut down as an exception occured: "+e);
108	running = false;
109	}
110	}
111	socket.close();
112	}
113
114	/**
115	* Overrides the {@link java.lang.Object#toString() Object.toString()}
116	* method to provide clean logging (every class should have this).
117	*
118	* This uses the uk.org.iscream.cms.server.util.NameFormat class
119	* to format the toString()
120	*
121	* @return the name of this class and its CVS revision
122	*/
123	public String toString() {
124	return FormatName.getName(
125	_name,
126	getClass().getName(),
127	REVISION);
128	}
129
130	//---PRIVATE METHODS---
131
132	//---ACCESSOR/MUTATOR METHODS---
133
134	//---ATTRIBUTES---
135
136	/**
137	* This is the friendly identifier of the
138	* component this class is running in.
139	* eg, a Filter may be called "filter1",
140	* If this class does not have an owning
141	* component, a name from the configuration
142	* can be placed here. This name could also
143	* be changed to null for utility classes.
144	*/
145	private String _name = FilterMain.NAME;
146
147	/**
148	* This holds a reference to the
149	* system logger that is being used.
150	*/
151	private Logger _logger = ReferenceManager.getInstance().getLogger();
152
153	/**
154	* The port that this reader is using
155	*/
156	int _port;
157
158	/**
159	* The Queue object
160	*/
161	Queue _queue;
162
163	//---STATIC ATTRIBUTES---
164
165	}