server/filter/TCPReader.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 uk.org.iscream.cms.server.core.*;
import uk.org.iscream.cms.server.componentmanager.*;
import uk.org.iscream.cms.server.filter.*;
import java.net.Socket;
import java.net.ServerSocket;
import java.io.OutputStream;
import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;
import uk.org.iscream.cms.server.util.*;

/**
 * Reads TCP Heartbeats from the host applications.
 *
 * @author  $Author: tdb $
 * @version $Id: TCPReader.java,v 1.17 2002/05/18 18:16:02 tdb Exp $
 */
class TCPReader extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.17 $";
    
//---STATIC METHODS---

//---CONSTRUCTORS---

    /**
     * Constructs a new TCPReader
     *
     * @param queue A reference to our Queue
     * @param port The port that the TCPReader will listen on
     */
    public TCPReader(int port, Queue queue) {
        // set the Thread name
        setName("filter.TCPReader");
        
        _port = port;
        _queue = queue;
        _logger.write(toString(), Logger.SYSINIT, "started");
    }

    

//---PUBLIC METHODS---

    /**
     * The run() method is the main loop for this thread, and we
     * will remain in here until such a point as something goes
     * wrong with the listening. After initially setting up the
     * ServerSocket we go round a while loop receiving connections
     * and then passing them off to other processes to deal with.
     */
    public void run(){
        // setup an empty ACL defaulting to ALLOW
        ACL acl = new ACL(ACL.ALLOW);
        
        // Setup the ServerSocket so that clients can connect
        ServerSocket listenPort=null;
        try{
            listenPort = new ACLServerSocket(acl, _port);
        }
        catch(IOException e){
            _logger.write(toString(), Logger.FATAL, "Failed to setup ServerSocket: " + e);
            return;
        }
        
        // Log what machine/port we're listening on
        try{
            _logger.write(toString(), Logger.SYSMSG, "TCPReader listening on "
                                        +InetAddress.getLocalHost().getHostName()
                                        +"/"+InetAddress.getLocalHost().getHostAddress()
                                        +" port "+listenPort.getLocalPort());
        }
        catch(UnknownHostException e){
            _logger.write(toString(), Logger.SYSMSG, "TCPReader listening on UnknownHost "
                                        +"port "+listenPort.getLocalPort());
        }
        
        // We use this boolean so we can break out of the while loop if we want
        boolean run = true;
        
        // Loop round constantly until we decide to stop
        ConfigurationProxy cp = ConfigurationProxy.getInstance();
        String stringACL = "";
        String newStringACL = "";
        while(run){
            // get hold of the ACL in the configuration
            try {
                newStringACL = cp.getProperty("Filter." + FilterMain.NAME, "Filter.TCPACL");
            }
            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 TCPReader, 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;
            }
            Socket hostSocket=null;
            try{
                _logger.write(toString(), Logger.DEBUG, "Waiting for Connection");
                // This will block until a host connects - at which point we get a Socket
                hostSocket = listenPort.accept();
                _logger.write(toString(), Logger.DEBUG, "Connection accepted from: " + hostSocket.toString());
            }
            catch(IOException e){
                // Something went wrong with the ServerSocket, so we'll stop listening
                run=false;
            }
            // If we've stopped on the line above we won't want to try this !
            if(run){
                try {
                    // Setup the TCPReaderInit and start it
                    TCPReaderInit init = new TCPReaderInit(hostSocket, _queue);
                    // and start it
                    init.start();
                } catch (IOException e) {
                    _logger.write(toString(), Logger.ERROR, e.toString());
                }
            }
        }
        // Best log the fact that we're stopping
        _logger.write(toString(), Logger.FATAL, "Fatal error, shutdown pending");
    }

    /**
     * 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 on which the server should listen.
     */
    private int _port;
    
    /**
     * A reference to our Queue
     */
    private Queue _queue;
    
//---STATIC ATTRIBUTES---

}
Revision:	1.18
Committed:	Tue May 21 16:47:17 2002 UTC (22 years ago) by tdb
Branch:	MAIN
Changes since 1.17:	+3 -2 lines
Log Message:	Added URL to GPL headers.
#	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 uk.org.iscream.cms.server.core.*;
26	import uk.org.iscream.cms.server.componentmanager.*;
27	import uk.org.iscream.cms.server.filter.*;
28	import java.net.Socket;
29	import java.net.ServerSocket;
30	import java.io.OutputStream;
31	import java.io.IOException;
32	import java.net.InetAddress;
33	import java.net.UnknownHostException;
34	import uk.org.iscream.cms.server.util.*;
35
36	/**
37	* Reads TCP Heartbeats from the host applications.
38	*
39	* @author $Author: tdb $
40	* @version $Id: TCPReader.java,v 1.17 2002/05/18 18:16:02 tdb Exp $
41	*/
42	class TCPReader extends Thread {
43
44	//---FINAL ATTRIBUTES---
45
46	/**
47	* The current CVS revision of this class
48	*/
49	public final String REVISION = "$Revision: 1.17 $";
50
51	//---STATIC METHODS---
52
53	//---CONSTRUCTORS---
54
55	/**
56	* Constructs a new TCPReader
57	*
58	* @param queue A reference to our Queue
59	* @param port The port that the TCPReader will listen on
60	*/
61	public TCPReader(int port, Queue queue) {
62	// set the Thread name
63	setName("filter.TCPReader");
64
65	_port = port;
66	_queue = queue;
67	_logger.write(toString(), Logger.SYSINIT, "started");
68	}
69
70
71
72	//---PUBLIC METHODS---
73
74	/**
75	* The run() method is the main loop for this thread, and we
76	* will remain in here until such a point as something goes
77	* wrong with the listening. After initially setting up the
78	* ServerSocket we go round a while loop receiving connections
79	* and then passing them off to other processes to deal with.
80	*/
81	public void run(){
82	// setup an empty ACL defaulting to ALLOW
83	ACL acl = new ACL(ACL.ALLOW);
84
85	// Setup the ServerSocket so that clients can connect
86	ServerSocket listenPort=null;
87	try{
88	listenPort = new ACLServerSocket(acl, _port);
89	}
90	catch(IOException e){
91	_logger.write(toString(), Logger.FATAL, "Failed to setup ServerSocket: " + e);
92	return;
93	}
94
95	// Log what machine/port we're listening on
96	try{
97	_logger.write(toString(), Logger.SYSMSG, "TCPReader listening on "
98	+InetAddress.getLocalHost().getHostName()
99	+"/"+InetAddress.getLocalHost().getHostAddress()
100	+" port "+listenPort.getLocalPort());
101	}
102	catch(UnknownHostException e){
103	_logger.write(toString(), Logger.SYSMSG, "TCPReader listening on UnknownHost "
104	+"port "+listenPort.getLocalPort());
105	}
106
107	// We use this boolean so we can break out of the while loop if we want
108	boolean run = true;
109
110	// Loop round constantly until we decide to stop
111	ConfigurationProxy cp = ConfigurationProxy.getInstance();
112	String stringACL = "";
113	String newStringACL = "";
114	while(run){
115	// get hold of the ACL in the configuration
116	try {
117	newStringACL = cp.getProperty("Filter." + FilterMain.NAME, "Filter.TCPACL");
118	}
119	catch(PropertyNotFoundException e) {
120	// if we can't find it, we'll just use a null ACL
121	newStringACL = "";
122	_logger.write(toString(), Logger.WARNING, "No ACL found for TCPReader, using empty ACL instead: " + e);
123	}
124	// check to see if the ACL has changed
125	if(!newStringACL.equals(stringACL)) {
126	_logger.write(toString(), Logger.SYSMSG, "Reloading Access Control List");
127	// clear the ACL
128	acl.clear();
129	// set the default to something sane
130	acl.setDefaultMode(ACL.ALLOW);
131	// add the new ACL (this may change the default)
132	acl.add(newStringACL);
133	stringACL = newStringACL;
134	}
135	Socket hostSocket=null;
136	try{
137	_logger.write(toString(), Logger.DEBUG, "Waiting for Connection");
138	// This will block until a host connects - at which point we get a Socket
139	hostSocket = listenPort.accept();
140	_logger.write(toString(), Logger.DEBUG, "Connection accepted from: " + hostSocket.toString());
141	}
142	catch(IOException e){
143	// Something went wrong with the ServerSocket, so we'll stop listening
144	run=false;
145	}
146	// If we've stopped on the line above we won't want to try this !
147	if(run){
148	try {
149	// Setup the TCPReaderInit and start it
150	TCPReaderInit init = new TCPReaderInit(hostSocket, _queue);
151	// and start it
152	init.start();
153	} catch (IOException e) {
154	_logger.write(toString(), Logger.ERROR, e.toString());
155	}
156	}
157	}
158	// Best log the fact that we're stopping
159	_logger.write(toString(), Logger.FATAL, "Fatal error, shutdown pending");
160	}
161
162	/**
163	* Overrides the {@link java.lang.Object#toString() Object.toString()}
164	* method to provide clean logging (every class should have this).
165	*
166	* This uses the uk.org.iscream.cms.server.util.NameFormat class
167	* to format the toString()
168	*
169	* @return the name of this class and its CVS revision
170	*/
171	public String toString() {
172	return FormatName.getName(
173	_name,
174	getClass().getName(),
175	REVISION);
176	}
177
178	//---PRIVATE METHODS---
179
180	//---ACCESSOR/MUTATOR METHODS---
181
182	//---ATTRIBUTES---
183
184	/**
185	* This is the friendly identifier of the
186	* component this class is running in.
187	* eg, a Filter may be called "filter1",
188	* If this class does not have an owning
189	* component, a name from the configuration
190	* can be placed here. This name could also
191	* be changed to null for utility classes.
192	*/
193	private String _name = FilterMain.NAME;
194
195	/**
196	* This holds a reference to the
197	* system logger that is being used.
198	*/
199	private Logger _logger = ReferenceManager.getInstance().getLogger();
200
201	/**
202	* The port on which the server should listen.
203	*/
204	private int _port;
205
206	/**
207	* A reference to our Queue
208	*/
209	private Queue _queue;
210
211	//---STATIC ATTRIBUTES---
212
213	}