server/filter/UDPReader.java

/* 
 * i-scream central monitoring system
 * http://www.i-scream.org
 * 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 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 1.26 2004/08/01 10:40:59 tdb Exp $
 */
public class UDPReader extends Thread{

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.26 $";
    
    /**
     * 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:	1.27
Committed:	Sun Sep 25 09:57:42 2005 UTC (18 years, 7 months ago) by tdb
Branch:	MAIN
Changes since 1.26:	+2 -3 lines
Log Message:	Fix compile problems on j2se 1.5 - our Queue class conflicted with one in java.util. Also fix an API issue when running the server on Windows - the println method sends '\r\n' on Windows instead of '\n' on Unix, which confuses applications such as ihost. Patch provided by: skel
#	Content
1	/*
2	* i-scream central monitoring system
3	* http://www.i-scream.org
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 uk.org.iscream.cms.server.core.*;
28	import uk.org.iscream.cms.server.componentmanager.*;
29	import uk.org.iscream.cms.server.filter.*;
30	import uk.org.iscream.cms.util.*;
31
32	/**
33	* This class contains the main method to be run by
34	* the filterd. It harvests UDP traffic, and queues it.
35	*
36	* @author $Author: tdb $
37	* @version $Id: UDPReader.java,v 1.26 2004/08/01 10:40:59 tdb Exp $
38	*/
39	public class UDPReader extends Thread{
40
41	//---FINAL ATTRIBUTES---
42
43	/**
44	* The current CVS revision of this class
45	*/
46	public final String REVISION = "$Revision: 1.26 $";
47
48	/**
49	* The maximum size of a packet
50	*/
51	private final int packetSizeLimit = 8192;
52
53	//---STATIC METHODS---
54
55	//---CONSTRUCTORS---
56
57	/**
58	* Constructs a new UDPReader.
59	*
60	* @param port The port on which we listen for UDP data
61	* @param queue The queue which we are using
62	*/
63	public UDPReader(int port, Queue queue){
64	// set the Thread name
65	setName("filter.UDPReader");
66
67	_port = port;
68	_queue = queue;
69	_logger.write(toString(), Logger.SYSINIT, "started");
70	}
71
72	//---PUBLIC METHODS---
73
74	/**
75	* The main method in the class. Reads and queues XML sent
76	* over UDP.
77	*/
78	public void run() {
79	// setup an empty ACL defaulting to ALLOW
80	ACL acl = new ACL(ACL.ALLOW);
81
82	// setup a Datagram socket
83	DatagramSocket socket = null;
84	try {
85	socket = new ACLDatagramSocket(acl, _port);
86	}
87	catch (BindException e){
88	_logger.write(this.toString(), Logger.FATAL, "Could not start the UDPReader thread on port "+_port+" as this port was already in use.");
89	return;
90	}
91	catch (Exception e){
92	_logger.write(this.toString(), Logger.FATAL, "Could not start the UDPReader thread on port "+_port+".");
93	return;
94	}
95
96	_logger.write(this.toString(), Logger.SYSMSG, "UDPReader thread ready and listening for UDP packets on port "+_port);
97
98	byte[] buf;
99
100	ConfigurationProxy cp = ConfigurationProxy.getInstance();
101	String stringACL = "";
102	String newStringACL = "";
103
104	// read UDP packets and queue them
105	boolean running = true;
106	while (running){
107	// get hold of the ACL in the configuration
108	try {
109	newStringACL = cp.getProperty("Filter." + FilterMain.NAME, "Filter.UDPACL");
110	}
111	catch(PropertyNotFoundException e) {
112	// if we can't find it, we'll just use a null ACL
113	newStringACL = "";
114	_logger.write(toString(), Logger.WARNING, "No ACL found for UDPReader, using empty ACL instead: " + e);
115	}
116	// check to see if the ACL has changed
117	if(!newStringACL.equals(stringACL)) {
118	_logger.write(toString(), Logger.SYSMSG, "Reloading Access Control List");
119	// clear the ACL
120	acl.clear();
121	// set the default to something sane
122	acl.setDefaultMode(ACL.ALLOW);
123	// add the new ACL (this may change the default)
124	acl.add(newStringACL);
125	stringACL = newStringACL;
126	}
127	try {
128
129	// receive request and put it in the Queue
130	buf = new byte[packetSizeLimit];
131	DatagramPacket packet = new DatagramPacket(buf, buf.length);
132	socket.receive(packet);
133	String xml = new String(packet.getData());
134	_queue.add(xml);
135	}
136	catch (IOException e) {
137	_logger.write(this.toString(), Logger.WARNING, "This UDPReader thread has been shut down as an exception occured: "+e);
138	running = false;
139	}
140	}
141	socket.close();
142	}
143
144	/**
145	* Overrides the {@link java.lang.Object#toString() Object.toString()}
146	* method to provide clean logging (every class should have this).
147	*
148	* This uses the uk.org.iscream.cms.util.NameFormat class
149	* to format the toString()
150	*
151	* @return the name of this class and its CVS revision
152	*/
153	public String toString() {
154	return FormatName.getName(
155	_name,
156	getClass().getName(),
157	REVISION);
158	}
159
160	//---PRIVATE METHODS---
161
162	//---ACCESSOR/MUTATOR METHODS---
163
164	//---ATTRIBUTES---
165
166	/**
167	* This is the friendly identifier of the
168	* component this class is running in.
169	* eg, a Filter may be called "filter1",
170	* If this class does not have an owning
171	* component, a name from the configuration
172	* can be placed here. This name could also
173	* be changed to null for utility classes.
174	*/
175	private String _name = FilterMain.NAME;
176
177	/**
178	* This holds a reference to the
179	* system logger that is being used.
180	*/
181	private Logger _logger = ReferenceManager.getInstance().getLogger();
182
183	/**
184	* The port that this reader is using
185	*/
186	int _port;
187
188	/**
189	* The Queue object
190	*/
191	Queue _queue;
192
193	//---STATIC ATTRIBUTES---
194
195	}