server/filtermanager/HostListener.java

//---PACKAGE DECLARATION---
package uk.ac.ukc.iscream.filtermanager;

//---IMPORTS---
import uk.ac.ukc.iscream.core.*;
import uk.ac.ukc.iscream.componentmanager.*;
import uk.ac.ukc.iscream.filter.*;
import uk.ac.ukc.iscream.util.*;
import java.net.*;
import java.io.*;

/**
 * A socket listener to listen for new hosts registering with the system.
 * When a host makes a connection, the connecton is past to an instance
 * of the HostInit class, which handles further communication.
 *
 * @author  $Author: ajm4 $
 * @version $Id: HostListener.java,v 1.4 2000/12/12 19:17:02 ajm4 Exp $
 */
class HostListener extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.4 $";
    
//---STATIC METHODS---

//---CONSTRUCTORS---

        /**
     * Constructs a new listener
     *
         * @param listenPort The port that the server will listen on.
         */
    public HostListener(int listenPort) {
        _listenPort = listenPort;
        _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(){
        ServerSocket listenSocket=null;
                // We use this boolean so we can break out of the while loop if we want
        boolean run = true;
        try{
                        // Setup the ServerSocket so that clients can connect
            listenSocket = new ServerSocket(_listenPort);
        }
        catch(IOException e){
        }
                // Log what machine/port we're listening on
                try{
                        _logger.write(toString(), Logger.SYSMSG, "Server listening on "
                                                                                +InetAddress.getLocalHost().getHostName()
                                                                                +"/"+InetAddress.getLocalHost().getHostAddress()
                                                                                +" port "+listenSocket.getLocalPort());
                }
                catch(UnknownHostException e){
                        _logger.write(toString(), Logger.SYSMSG, "Server listening on UnknownHost "
                                                                                +"port "+listenSocket.getLocalPort());
                }
                // Loop round constantly until we decide to stop
        while(run){
            Socket hostSocket=null;
            try{
                _logger.write(toString(), Logger.SYSMSG, "Waiting for Connection");
                                // This will block until a host connects - at which point we get a Socket
                hostSocket = listenSocket.accept();
                _logger.write(toString(), Logger.SYSMSG, "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 HostInit so it can carry on communications with the host
                    HostInit init = new HostInit(hostSocket);
                                    // 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.ac.ukc.iscream.util.NameFormat class
     * to format the toString()
     *
     * @return the name of this class and its CVS revision
     */
    public String toString() {
        return FormatName.getName(
            _name,
            this.getClass().getName(),
            REVISION);
    }

//---PRIVATE METHODS---

//---ACCESSOR/MUTATOR METHODS---

//---ATTRIBUTES---
    
    /**
     * This holds a reference to the
     * system logger that is being used.
     */
    private Logger _logger = ReferenceManager.getInstance().getLogger();
    
    /**
     * 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 = FilterManager.NAME;
    
    /**
         * The port on which the server should listen.
         */
    private int _listenPort;
    
//---STATIC ATTRIBUTES---

}
Revision:	1.5
Committed:	Thu Jan 18 23:17:54 2001 UTC (23 years, 4 months ago) by tdb
Branch:	MAIN
Changes since 1.4:	+4 -3 lines
Log Message:	Changes to reflect move of Component, ComponentStartException, and the ReferenceManager from util to componentmanager.
#	User	Rev	Content
1	tdb	1.1	//---PACKAGE DECLARATION---
2	tdb	1.2	package uk.ac.ukc.iscream.filtermanager;
3	tdb	1.1
4			//---IMPORTS---
5			import uk.ac.ukc.iscream.core.*;
6	tdb	1.5	import uk.ac.ukc.iscream.componentmanager.*;
7	tdb	1.1	import uk.ac.ukc.iscream.filter.*;
8	tdb	1.3	import uk.ac.ukc.iscream.util.*;
9			import java.net.*;
10			import java.io.*;
11	tdb	1.1
12			/**
13			* A socket listener to listen for new hosts registering with the system.
14			* When a host makes a connection, the connecton is past to an instance
15			* of the HostInit class, which handles further communication.
16			*
17	tdb	1.5	* @author $Author: ajm4 $
18			* @version $Id: HostListener.java,v 1.4 2000/12/12 19:17:02 ajm4 Exp $
19	tdb	1.1	*/
20			class HostListener extends Thread {
21
22			//---FINAL ATTRIBUTES---
23
24			/**
25			* The current CVS revision of this class
26			*/
27	tdb	1.5	public final String REVISION = "$Revision: 1.4 $";
28	tdb	1.1
29			//---STATIC METHODS---
30
31			//---CONSTRUCTORS---
32
33			/**
34			* Constructs a new listener
35			*
36	tdb	1.3	* @param listenPort The port that the server will listen on.
37	tdb	1.1	*/
38	tdb	1.3	public HostListener(int listenPort) {
39			_listenPort = listenPort;
40	tdb	1.1	_logger.write(toString(), Logger.SYSINIT, "started");
41			}
42
43
44
45			//---PUBLIC METHODS---
46
47			/**
48			* The run() method is the main loop for this thread, and we
49			* will remain in here until such a point as something goes
50			* wrong with the listening. After initially setting up the
51			* ServerSocket we go round a while loop receiving connections
52			* and then passing them off to other processes to deal with.
53			*/
54			public void run(){
55	tdb	1.3	ServerSocket listenSocket=null;
56	tdb	1.1	// We use this boolean so we can break out of the while loop if we want
57			boolean run = true;
58			try{
59			// Setup the ServerSocket so that clients can connect
60	tdb	1.3	listenSocket = new ServerSocket(_listenPort);
61	tdb	1.1	}
62			catch(IOException e){
63			}
64			// Log what machine/port we're listening on
65			try{
66			_logger.write(toString(), Logger.SYSMSG, "Server listening on "
67			+InetAddress.getLocalHost().getHostName()
68			+"/"+InetAddress.getLocalHost().getHostAddress()
69	tdb	1.3	+" port "+listenSocket.getLocalPort());
70	tdb	1.1	}
71			catch(UnknownHostException e){
72			_logger.write(toString(), Logger.SYSMSG, "Server listening on UnknownHost "
73	tdb	1.3	+"port "+listenSocket.getLocalPort());
74	tdb	1.1	}
75			// Loop round constantly until we decide to stop
76			while(run){
77			Socket hostSocket=null;
78			try{
79			_logger.write(toString(), Logger.SYSMSG, "Waiting for Connection");
80			// This will block until a host connects - at which point we get a Socket
81	tdb	1.3	hostSocket = listenSocket.accept();
82	tdb	1.1	_logger.write(toString(), Logger.SYSMSG, "Connection accepted from: " + hostSocket.toString());
83			}
84			catch(IOException e){
85			// Something went wrong with the ServerSocket, so we'll stop listening
86			run=false;
87			}
88			// If we've stopped on the line above we won't want to try this !
89			if(run){
90			try {
91			// Setup the HostInit so it can carry on communications with the host
92	tdb	1.3	HostInit init = new HostInit(hostSocket);
93	tdb	1.1	// and start it
94			init.start();
95			} catch (IOException e) {
96			_logger.write(toString(), Logger.ERROR, e.toString());
97			}
98			}
99			}
100			// Best log the fact that we're stopping
101			_logger.write(toString(), Logger.FATAL, "Fatal error, shutdown pending");
102			}
103
104			/**
105			* Overrides the {@link java.lang.Object#toString() Object.toString()}
106			* method to provide clean logging (every class should have this).
107			*
108	ajm	1.4	* This uses the uk.ac.ukc.iscream.util.NameFormat class
109			* to format the toString()
110			*
111	tdb	1.1	* @return the name of this class and its CVS revision
112			*/
113			public String toString() {
114	ajm	1.4	return FormatName.getName(
115			_name,
116			this.getClass().getName(),
117			REVISION);
118	tdb	1.1	}
119
120			//---PRIVATE METHODS---
121
122			//---ACCESSOR/MUTATOR METHODS---
123
124			//---ATTRIBUTES---
125
126			/**
127	ajm	1.4	* This holds a reference to the
128			* system logger that is being used.
129			*/
130			private Logger _logger = ReferenceManager.getInstance().getLogger();
131
132			/**
133			* This is the friendly identifier of the
134			* component this class is running in.
135			* eg, a Filter may be called "filter1",
136			* If this class does not have an owning
137			* component, a name from the configuration
138			* can be placed here. This name could also
139			* be changed to null for utility classes.
140	tdb	1.1	*/
141	ajm	1.4	private String _name = FilterManager.NAME;
142	tdb	1.1
143			/**
144			* The port on which the server should listen.
145			*/
146	tdb	1.3	private int _listenPort;
147	tdb	1.1
148			//---STATIC ATTRIBUTES---
149
150			}