server/filter/TCPReader.java

/* 
 * i-scream central monitoring system
 * 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 1.16 2002/03/21 13:01:21 tdb Exp $
 */
class TCPReader extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.16 $";
    
//---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:	1.17
Committed:	Sat May 18 18:16:02 2002 UTC (22 years ago) by tdb
Branch:	MAIN
Changes since 1.16:	+21 -2 lines
Log Message:	i-scream is now licensed under the GPL. I've added the GPL headers to every source file, and put a full copy of the license in the appropriate places. I think I've covered everything. This is going to be a mad commit ;)
#	Content
1	/*
2	* i-scream central monitoring system
3	* Copyright (C) 2000-2002 i-scream
4	*
5	* This program is free software; you can redistribute it and/or
6	* modify it under the terms of the GNU General Public License
7	* as published by the Free Software Foundation; either version 2
8	* of the License, or (at your option) any later version.
9	*
10	* This program is distributed in the hope that it will be useful,
11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13	* GNU General Public License for more details.
14	*
15	* You should have received a copy of the GNU General Public License
16	* along with this program; if not, write to the Free Software
17	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18	*/
19
20	//---PACKAGE DECLARATION---
21	package uk.org.iscream.cms.server.filter;
22
23	//---IMPORTS---
24	import uk.org.iscream.cms.server.core.*;
25	import uk.org.iscream.cms.server.componentmanager.*;
26	import uk.org.iscream.cms.server.filter.*;
27	import java.net.Socket;
28	import java.net.ServerSocket;
29	import java.io.OutputStream;
30	import java.io.IOException;
31	import java.net.InetAddress;
32	import java.net.UnknownHostException;
33	import uk.org.iscream.cms.server.util.*;
34
35	/**
36	* Reads TCP Heartbeats from the host applications.
37	*
38	* @author $Author: tdb $
39	* @version $Id: TCPReader.java,v 1.16 2002/03/21 13:01:21 tdb Exp $
40	*/
41	class TCPReader extends Thread {
42
43	//---FINAL ATTRIBUTES---
44
45	/**
46	* The current CVS revision of this class
47	*/
48	public final String REVISION = "$Revision: 1.16 $";
49
50	//---STATIC METHODS---
51
52	//---CONSTRUCTORS---
53
54	/**
55	* Constructs a new TCPReader
56	*
57	* @param queue A reference to our Queue
58	* @param port The port that the TCPReader will listen on
59	*/
60	public TCPReader(int port, Queue queue) {
61	// set the Thread name
62	setName("filter.TCPReader");
63
64	_port = port;
65	_queue = queue;
66	_logger.write(toString(), Logger.SYSINIT, "started");
67	}
68
69
70
71	//---PUBLIC METHODS---
72
73	/**
74	* The run() method is the main loop for this thread, and we
75	* will remain in here until such a point as something goes
76	* wrong with the listening. After initially setting up the
77	* ServerSocket we go round a while loop receiving connections
78	* and then passing them off to other processes to deal with.
79	*/
80	public void run(){
81	// setup an empty ACL defaulting to ALLOW
82	ACL acl = new ACL(ACL.ALLOW);
83
84	// Setup the ServerSocket so that clients can connect
85	ServerSocket listenPort=null;
86	try{
87	listenPort = new ACLServerSocket(acl, _port);
88	}
89	catch(IOException e){
90	_logger.write(toString(), Logger.FATAL, "Failed to setup ServerSocket: " + e);
91	return;
92	}
93
94	// Log what machine/port we're listening on
95	try{
96	_logger.write(toString(), Logger.SYSMSG, "TCPReader listening on "
97	+InetAddress.getLocalHost().getHostName()
98	+"/"+InetAddress.getLocalHost().getHostAddress()
99	+" port "+listenPort.getLocalPort());
100	}
101	catch(UnknownHostException e){
102	_logger.write(toString(), Logger.SYSMSG, "TCPReader listening on UnknownHost "
103	+"port "+listenPort.getLocalPort());
104	}
105
106	// We use this boolean so we can break out of the while loop if we want
107	boolean run = true;
108
109	// Loop round constantly until we decide to stop
110	ConfigurationProxy cp = ConfigurationProxy.getInstance();
111	String stringACL = "";
112	String newStringACL = "";
113	while(run){
114	// get hold of the ACL in the configuration
115	try {
116	newStringACL = cp.getProperty("Filter." + FilterMain.NAME, "Filter.TCPACL");
117	}
118	catch(PropertyNotFoundException e) {
119	// if we can't find it, we'll just use a null ACL
120	newStringACL = "";
121	_logger.write(toString(), Logger.WARNING, "No ACL found for TCPReader, using empty ACL instead: " + e);
122	}
123	// check to see if the ACL has changed
124	if(!newStringACL.equals(stringACL)) {
125	_logger.write(toString(), Logger.SYSMSG, "Reloading Access Control List");
126	// clear the ACL
127	acl.clear();
128	// set the default to something sane
129	acl.setDefaultMode(ACL.ALLOW);
130	// add the new ACL (this may change the default)
131	acl.add(newStringACL);
132	stringACL = newStringACL;
133	}
134	Socket hostSocket=null;
135	try{
136	_logger.write(toString(), Logger.DEBUG, "Waiting for Connection");
137	// This will block until a host connects - at which point we get a Socket
138	hostSocket = listenPort.accept();
139	_logger.write(toString(), Logger.DEBUG, "Connection accepted from: " + hostSocket.toString());
140	}
141	catch(IOException e){
142	// Something went wrong with the ServerSocket, so we'll stop listening
143	run=false;
144	}
145	// If we've stopped on the line above we won't want to try this !
146	if(run){
147	try {
148	// Setup the TCPReaderInit and start it
149	TCPReaderInit init = new TCPReaderInit(hostSocket, _queue);
150	// and start it
151	init.start();
152	} catch (IOException e) {
153	_logger.write(toString(), Logger.ERROR, e.toString());
154	}
155	}
156	}
157	// Best log the fact that we're stopping
158	_logger.write(toString(), Logger.FATAL, "Fatal error, shutdown pending");
159	}
160
161	/**
162	* Overrides the {@link java.lang.Object#toString() Object.toString()}
163	* method to provide clean logging (every class should have this).
164	*
165	* This uses the uk.org.iscream.cms.server.util.NameFormat class
166	* to format the toString()
167	*
168	* @return the name of this class and its CVS revision
169	*/
170	public String toString() {
171	return FormatName.getName(
172	_name,
173	getClass().getName(),
174	REVISION);
175	}
176
177	//---PRIVATE METHODS---
178
179	//---ACCESSOR/MUTATOR METHODS---
180
181	//---ATTRIBUTES---
182
183	/**
184	* This is the friendly identifier of the
185	* component this class is running in.
186	* eg, a Filter may be called "filter1",
187	* If this class does not have an owning
188	* component, a name from the configuration
189	* can be placed here. This name could also
190	* be changed to null for utility classes.
191	*/
192	private String _name = FilterMain.NAME;
193
194	/**
195	* This holds a reference to the
196	* system logger that is being used.
197	*/
198	private Logger _logger = ReferenceManager.getInstance().getLogger();
199
200	/**
201	* The port on which the server should listen.
202	*/
203	private int _port;
204
205	/**
206	* A reference to our Queue
207	*/
208	private Queue _queue;
209
210	//---STATIC ATTRIBUTES---
211
212	}