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 1.18 2001/05/29 17:02:35 tdb Exp $
 */
public class UDPReader extends Thread{

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.18 $";
    
    /**
     * 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 udpACL = null;
        try {
            String stringACL = ConfigurationProxy.getInstance().getProperty(FilterMain.NAME, "Filter.UDPACL");
            udpACL = 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(udpACL != null) {
                            socket = new ACLDatagramSocket(udpACL, _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:	1.19
Committed:	Tue Mar 19 17:22:12 2002 UTC (22 years, 2 months ago) by tdb
Branch:	MAIN
Changes since 1.18:	+19 -4 lines
Log Message:	Added ACL support to the TCP and UDP parts of the Filter. Not so sure about doing the same to the CORBA input bit though :)
#	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	1.19	* @author $Author: tdb $
18			* @version $Id: UDPReader.java,v 1.18 2001/05/29 17:02:35 tdb 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	1.19	public final String REVISION = "$Revision: 1.18 $";
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	1.19	// get our ACL from the configuration
61			ACL udpACL = null;
62			try {
63			String stringACL = ConfigurationProxy.getInstance().getProperty(FilterMain.NAME, "Filter.UDPACL");
64			udpACL = new ACL(stringACL);
65			}
66			catch(PropertyNotFoundException e) {
67			_logger.write(toString(), Logger.WARNING, "No ACL found for UDPReader: " + e);
68			}
69	tdb	1.14
70			// setup a Datagram socket
71	pjm2	1.1	DatagramSocket socket = null;
72			try {
73	tdb	1.19	// use an ACLServerSocket if we have an ACL
74			if(udpACL != null) {
75			socket = new ACLDatagramSocket(udpACL, _port);
76			}
77			else {
78			socket = new DatagramSocket(_port);
79			}
80	pjm2	1.1	}
81			catch (BindException e){
82	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.");
83	pjm2	1.1	return;
84			}
85			catch (Exception e){
86	tdb	1.8	_logger.write(this.toString(), Logger.FATAL, "Could not start the UDPReader thread on port "+_port+".");
87	pjm2	1.1	return;
88			}
89
90	tdb	1.8	_logger.write(this.toString(), Logger.SYSMSG, "UDPReader thread ready and listening for UDP packets on port "+_port);
91	tdb	1.15
92	pjm2	1.1	byte[] buf;
93
94	tdb	1.14	// read UDP packets and queue them
95	pjm2	1.1	boolean running = true;
96			while (running){
97			try {
98	tdb	1.15
99			// receive request and put it in the Queue
100	pjm2	1.1	buf = new byte[packetSizeLimit];
101			DatagramPacket packet = new DatagramPacket(buf, buf.length);
102			socket.receive(packet);
103	tdb	1.12	String xml = new String(packet.getData());
104			_queue.add(xml);
105	pjm2	1.1	}
106			catch (IOException e) {
107	tdb	1.8	_logger.write(this.toString(), Logger.WARNING, "This UDPReader thread has been shut down as an exception occured: "+e);
108	tdb	1.14	running = false;
109	pjm2	1.1	}
110			}
111			socket.close();
112			}
113	tdb	1.15
114	tdb	1.6	/**
115			* Overrides the {@link java.lang.Object#toString() Object.toString()}
116			* method to provide clean logging (every class should have this).
117			*
118	tdb	1.18	* This uses the uk.org.iscream.cms.server.util.NameFormat class
119	ajm	1.11	* to format the toString()
120			*
121	tdb	1.6	* @return the name of this class and its CVS revision
122			*/
123			public String toString() {
124	ajm	1.11	return FormatName.getName(
125			_name,
126			getClass().getName(),
127			REVISION);
128	tdb	1.6	}
129
130			//---PRIVATE METHODS---
131
132			//---ACCESSOR/MUTATOR METHODS---
133
134			//---ATTRIBUTES---
135
136	ajm	1.11	/**
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	tdb	1.15
147	ajm	1.11	/**
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	tdb	1.8	int _port;
157	ajm	1.11
158			/**
159	tdb	1.12	* The Queue object
160	ajm	1.11	*/
161	tdb	1.15	Queue _queue;
162	tdb	1.6
163			//---STATIC ATTRIBUTES---
164
165	pjm2	1.1	}