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 ;)
#	User	Rev	Content
1	tdb	1.17	/*
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	tdb	1.1	//---PACKAGE DECLARATION---
21	tdb	1.12	package uk.org.iscream.cms.server.filter;
22	tdb	1.1
23			//---IMPORTS---
24	tdb	1.12	import uk.org.iscream.cms.server.core.*;
25			import uk.org.iscream.cms.server.componentmanager.*;
26			import uk.org.iscream.cms.server.filter.*;
27	tdb	1.1	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	tdb	1.12	import uk.org.iscream.cms.server.util.*;
34	tdb	1.1
35			/**
36	tdb	1.8	* Reads TCP Heartbeats from the host applications.
37	tdb	1.1	*
38	tdb	1.13	* @author $Author: tdb $
39	tdb	1.17	* @version $Id: TCPReader.java,v 1.16 2002/03/21 13:01:21 tdb Exp $
40	tdb	1.1	*/
41			class TCPReader extends Thread {
42
43			//---FINAL ATTRIBUTES---
44
45			/**
46			* The current CVS revision of this class
47			*/
48	tdb	1.17	public final String REVISION = "$Revision: 1.16 $";
49	tdb	1.1
50			//---STATIC METHODS---
51
52			//---CONSTRUCTORS---
53
54	tdb	1.16	/**
55	tdb	1.8	* Constructs a new TCPReader
56	tdb	1.1	*
57	tdb	1.8	* @param queue A reference to our Queue
58	tdb	1.16	* @param port The port that the TCPReader will listen on
59			*/
60	tdb	1.6	public TCPReader(int port, Queue queue) {
61	tdb	1.10	// set the Thread name
62			setName("filter.TCPReader");
63
64	tdb	1.1	_port = port;
65	tdb	1.6	_queue = queue;
66	tdb	1.1	_logger.write(toString(), Logger.SYSINIT, "started");
67			}
68
69
70
71			//---PUBLIC METHODS---
72
73	tdb	1.16	/**
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	tdb	1.1	public void run(){
81	tdb	1.16	// 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	tdb	1.13	}
89	tdb	1.16	catch(IOException e){
90			_logger.write(toString(), Logger.FATAL, "Failed to setup ServerSocket: " + e);
91			return;
92	tdb	1.13	}
93	tdb	1.16
94			// Log what machine/port we're listening on
95	tdb	1.1	try{
96	tdb	1.16	_logger.write(toString(), Logger.SYSMSG, "TCPReader listening on "
97			+InetAddress.getLocalHost().getHostName()
98			+"/"+InetAddress.getLocalHost().getHostAddress()
99			+" port "+listenPort.getLocalPort());
100	tdb	1.1	}
101	tdb	1.16	catch(UnknownHostException e){
102			_logger.write(toString(), Logger.SYSMSG, "TCPReader listening on UnknownHost "
103			+"port "+listenPort.getLocalPort());
104	tdb	1.1	}
105	tdb	1.13
106	tdb	1.16	// We use this boolean so we can break out of the while loop if we want
107	tdb	1.13	boolean run = true;
108	tdb	1.16
109			// Loop round constantly until we decide to stop
110			ConfigurationProxy cp = ConfigurationProxy.getInstance();
111			String stringACL = "";
112			String newStringACL = "";
113	tdb	1.1	while(run){
114	tdb	1.16	// 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	tdb	1.1	try{
136	tdb	1.9	_logger.write(toString(), Logger.DEBUG, "Waiting for Connection");
137	tdb	1.16	// This will block until a host connects - at which point we get a Socket
138	tdb	1.1	hostSocket = listenPort.accept();
139	tdb	1.9	_logger.write(toString(), Logger.DEBUG, "Connection accepted from: " + hostSocket.toString());
140	tdb	1.1	}
141			catch(IOException e){
142	tdb	1.16	// Something went wrong with the ServerSocket, so we'll stop listening
143	tdb	1.1	run=false;
144			}
145	tdb	1.16	// If we've stopped on the line above we won't want to try this !
146	tdb	1.1	if(run){
147	tdb	1.16	try {
148			// Setup the TCPReaderInit and start it
149	tdb	1.6	TCPReaderInit init = new TCPReaderInit(hostSocket, _queue);
150	tdb	1.16	// and start it
151	tdb	1.1	init.start();
152			} catch (IOException e) {
153			_logger.write(toString(), Logger.ERROR, e.toString());
154			}
155			}
156			}
157	tdb	1.16	// Best log the fact that we're stopping
158	tdb	1.1	_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	tdb	1.12	* This uses the uk.org.iscream.cms.server.util.NameFormat class
166	ajm	1.5	* to format the toString()
167			*
168	tdb	1.1	* @return the name of this class and its CVS revision
169			*/
170			public String toString() {
171	ajm	1.5	return FormatName.getName(
172			_name,
173			getClass().getName(),
174			REVISION);
175	tdb	1.1	}
176
177			//---PRIVATE METHODS---
178
179			//---ACCESSOR/MUTATOR METHODS---
180
181			//---ATTRIBUTES---
182
183			/**
184	ajm	1.5	* 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	tdb	1.1	*/
198	ajm	1.5	private Logger _logger = ReferenceManager.getInstance().getLogger();
199	tdb	1.1
200			/**
201	tdb	1.16	* The port on which the server should listen.
202			*/
203	tdb	1.1	private int _port;
204
205	tdb	1.8	/**
206			* A reference to our Queue
207			*/
208	tdb	1.6	private Queue _queue;
209	tdb	1.1
210			//---STATIC ATTRIBUTES---
211
212			}