server/filter/UDPReader.java

/* 
 * i-scream central monitoring system
 * http://www.i-scream.org.uk
 * Copyright (C) 2000-2002 i-scream
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

//---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.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 1.24 2002/05/21 16:47:17 tdb Exp $
 */
public class UDPReader extends Thread{

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.24 $";
    
    /**
     * 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 an empty ACL defaulting to ALLOW
        ACL acl = new ACL(ACL.ALLOW);
        
        // setup a Datagram socket
        DatagramSocket socket = null;
        try {
            socket = new ACLDatagramSocket(acl, _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;
        
        ConfigurationProxy cp = ConfigurationProxy.getInstance();
        String stringACL = "";
        String newStringACL = "";
        
        // read UDP packets and queue them
        boolean running = true;
        while (running){
            // get hold of the ACL in the configuration
            try {
                newStringACL = cp.getProperty("Filter." + FilterMain.NAME, "Filter.UDPACL");
            }
            catch(PropertyNotFoundException e) {
                // if we can't find it, we'll just use a null ACL
                newStringACL = "";
                _logger.write(toString(), Logger.WARNING, "No ACL found for UDPReader, using empty ACL instead: " + e);
            }
            // check to see if the ACL has changed
            if(!newStringACL.equals(stringACL)) {
                _logger.write(toString(), Logger.SYSMSG, "Reloading Access Control List");
                // clear the ACL
                acl.clear();
                // set the default to something sane
                acl.setDefaultMode(ACL.ALLOW);
                // add the new ACL (this may change the default)
                acl.add(newStringACL);
                stringACL = newStringACL;
            }
            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.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:	1.25
Committed:	Wed Feb 5 16:43:47 2003 UTC (21 years, 4 months ago) by tdb
Branch:	MAIN
Changes since 1.24:	+4 -4 lines
Log Message:	Changed the server to use the external util package. Quite a minor change, but does affect a lot of files.
#	Content
1	/*
2	* i-scream central monitoring system
3	* http://www.i-scream.org.uk
4	* Copyright (C) 2000-2002 i-scream
5	*
6	* This program is free software; you can redistribute it and/or
7	* modify it under the terms of the GNU General Public License
8	* as published by the Free Software Foundation; either version 2
9	* of the License, or (at your option) any later version.
10	*
11	* This program is distributed in the hope that it will be useful,
12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14	* GNU General Public License for more details.
15	*
16	* You should have received a copy of the GNU General Public License
17	* along with this program; if not, write to the Free Software
18	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19	*/
20
21	//---PACKAGE DECLARATION---
22	package uk.org.iscream.cms.server.filter;
23
24	//---IMPORTS---
25	import java.io.*;
26	import java.net.*;
27	import java.util.*;
28	import uk.org.iscream.cms.server.core.*;
29	import uk.org.iscream.cms.server.componentmanager.*;
30	import uk.org.iscream.cms.server.filter.*;
31	import uk.org.iscream.cms.util.*;
32
33	/**
34	* This class contains the main method to be run by
35	* the filterd. It harvests UDP traffic, and queues it.
36	*
37	* @author $Author: tdb $
38	* @version $Id: UDPReader.java,v 1.24 2002/05/21 16:47:17 tdb Exp $
39	*/
40	public class UDPReader extends Thread{
41
42	//---FINAL ATTRIBUTES---
43
44	/**
45	* The current CVS revision of this class
46	*/
47	public final String REVISION = "$Revision: 1.24 $";
48
49	/**
50	* The maximum size of a packet
51	*/
52	private final int packetSizeLimit = 8192;
53
54	//---STATIC METHODS---
55
56	//---CONSTRUCTORS---
57
58	/**
59	* Constructs a new UDPReader.
60	*
61	* @param port The port on which we listen for UDP data
62	* @param queue The queue which we are using
63	*/
64	public UDPReader(int port, Queue queue){
65	// set the Thread name
66	setName("filter.UDPReader");
67
68	_port = port;
69	_queue = queue;
70	_logger.write(toString(), Logger.SYSINIT, "started");
71	}
72
73	//---PUBLIC METHODS---
74
75	/**
76	* The main method in the class. Reads and queues XML sent
77	* over UDP.
78	*/
79	public void run() {
80	// setup an empty ACL defaulting to ALLOW
81	ACL acl = new ACL(ACL.ALLOW);
82
83	// setup a Datagram socket
84	DatagramSocket socket = null;
85	try {
86	socket = new ACLDatagramSocket(acl, _port);
87	}
88	catch (BindException e){
89	_logger.write(this.toString(), Logger.FATAL, "Could not start the UDPReader thread on port "+_port+" as this port was already in use.");
90	return;
91	}
92	catch (Exception e){
93	_logger.write(this.toString(), Logger.FATAL, "Could not start the UDPReader thread on port "+_port+".");
94	return;
95	}
96
97	_logger.write(this.toString(), Logger.SYSMSG, "UDPReader thread ready and listening for UDP packets on port "+_port);
98
99	byte[] buf;
100
101	ConfigurationProxy cp = ConfigurationProxy.getInstance();
102	String stringACL = "";
103	String newStringACL = "";
104
105	// read UDP packets and queue them
106	boolean running = true;
107	while (running){
108	// get hold of the ACL in the configuration
109	try {
110	newStringACL = cp.getProperty("Filter." + FilterMain.NAME, "Filter.UDPACL");
111	}
112	catch(PropertyNotFoundException e) {
113	// if we can't find it, we'll just use a null ACL
114	newStringACL = "";
115	_logger.write(toString(), Logger.WARNING, "No ACL found for UDPReader, using empty ACL instead: " + e);
116	}
117	// check to see if the ACL has changed
118	if(!newStringACL.equals(stringACL)) {
119	_logger.write(toString(), Logger.SYSMSG, "Reloading Access Control List");
120	// clear the ACL
121	acl.clear();
122	// set the default to something sane
123	acl.setDefaultMode(ACL.ALLOW);
124	// add the new ACL (this may change the default)
125	acl.add(newStringACL);
126	stringACL = newStringACL;
127	}
128	try {
129
130	// receive request and put it in the Queue
131	buf = new byte[packetSizeLimit];
132	DatagramPacket packet = new DatagramPacket(buf, buf.length);
133	socket.receive(packet);
134	String xml = new String(packet.getData());
135	_queue.add(xml);
136	}
137	catch (IOException e) {
138	_logger.write(this.toString(), Logger.WARNING, "This UDPReader thread has been shut down as an exception occured: "+e);
139	running = false;
140	}
141	}
142	socket.close();
143	}
144
145	/**
146	* Overrides the {@link java.lang.Object#toString() Object.toString()}
147	* method to provide clean logging (every class should have this).
148	*
149	* This uses the uk.org.iscream.cms.util.NameFormat class
150	* to format the toString()
151	*
152	* @return the name of this class and its CVS revision
153	*/
154	public String toString() {
155	return FormatName.getName(
156	_name,
157	getClass().getName(),
158	REVISION);
159	}
160
161	//---PRIVATE METHODS---
162
163	//---ACCESSOR/MUTATOR METHODS---
164
165	//---ATTRIBUTES---
166
167	/**
168	* This is the friendly identifier of the
169	* component this class is running in.
170	* eg, a Filter may be called "filter1",
171	* If this class does not have an owning
172	* component, a name from the configuration
173	* can be placed here. This name could also
174	* be changed to null for utility classes.
175	*/
176	private String _name = FilterMain.NAME;
177
178	/**
179	* This holds a reference to the
180	* system logger that is being used.
181	*/
182	private Logger _logger = ReferenceManager.getInstance().getLogger();
183
184	/**
185	* The port that this reader is using
186	*/
187	int _port;
188
189	/**
190	* The Queue object
191	*/
192	Queue _queue;
193
194	//---STATIC ATTRIBUTES---
195
196	}