server/clientinterface/TCPDataHandler.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.clientinterface;

//---IMPORTS---
import uk.org.iscream.cms.util.*;
import uk.org.iscream.cms.server.componentmanager.*;
import uk.org.iscream.cms.server.core.*;
import java.net.Socket;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.PrintWriter;
import java.io.InputStreamReader;

/**
 * Acts as a Data Handler to a TCP based client, providing
 * it with a constant stream of XML data for the hosts the
 * client has requested.
 *
 * @author  $Author: tdb $
 * @version $Id: TCPDataHandler.java,v 1.17 2004/08/01 10:40:48 tdb Exp $
 */
class TCPDataHandler extends Thread {

//---FINAL ATTRIBUTES---

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

//---CONSTRUCTORS---
    
    /**
     * Construct a new TCPDataHandler with a Socket provided
     * by the Control Handler.
     *
     * @param socket The socket to which the Client has connected
     * @throws IOException if something goes wrong, the Control Handler can deal with it
     */
    public TCPDataHandler(Socket socket) throws IOException {
        // set the Thread name
        setName("clientinterface.TCPDataHandler");
        
        ConfigurationProxy cp = ConfigurationProxy.getInstance();
        String configName = "ClientInterface";
        // see if this Queue needs a size limit
        try {
            int queueSizeLimit = Integer.parseInt(cp.getProperty(configName, "Queue.SizeLimit"));
            String queueRemoveAlgorithm = cp.getProperty(configName, "Queue.RemoveAlgorithm");
            int algorithm = StringUtils.getStringPos(queueRemoveAlgorithm, Queue.algorithms);
            if(algorithm != -1) {
                _logger.write(toString(), Logger.DEBUG, "Starting Queue with size limit of "+queueSizeLimit+", using remove algorithm "+queueRemoveAlgorithm);
                // we have valid values, so lets start it.
                _queue = new Queue(queueSizeLimit, algorithm);
            }
            else {
                _logger.write(toString(), Logger.WARNING, "Bad Queue Algorithm configuration, not known: "+queueRemoveAlgorithm);
                // just don't activate a limit
                _queue = new Queue();
            }
            
        } catch (PropertyNotFoundException e) {
            _logger.write(toString(), Logger.DEBUG, "Optional config not set: "+e);
            // just don't activate a limit
            _queue = new Queue();
        } catch (NumberFormatException e) {
            _logger.write(toString(), Logger.WARNING, "Bad Queue SizeLimit configuration: "+e);
            // just don't activate a limit
            _queue = new Queue();
        }
        
        _socket = socket;
        // setup the reader and writer
        _socketIn = new BufferedReader(new InputStreamReader(_socket.getInputStream()));
        _socketOut = new PrintWriter(_socket.getOutputStream(), true);
        _logger.write(toString(), Logger.SYSINIT, "created");
    }
    
//---PUBLIC METHODS---
    /**
     * Main loop for the Data Handler, keeps sending data from
     * it's local Queue.
     */
    public void run() {
        run = true;
        _queueID = _queue.getQueue();
        // run until we get told to stop
        while(run) {
            // get some data, and send some data
            try {
                String xml = (String) _queue.get(_queueID);
                // if we're shutting down and we've been "bumped"
                // it's likely we'll get a null back, and we don't
                // want to send that on to the Client
                if(xml != null) {
                    _socketOut.print(xml + "\n");
                    _socketOut.flush();
                }
            }
            catch(InvalidQueueException e) {
                run = false;
                _logger.write(toString(), Logger.ERROR, "Queue failure: "+e);
            }
        }
        // if we get here we've been told to stop
        _logger.write(toString(), Logger.SYSMSG, "Shutting Down");
        // shut down the reader, writer and Socket
        try {
            _socketOut.close();
            _socketIn.close();
            _socket.close();
        }
        catch(IOException e) {
            _logger.write(toString(), Logger.ERROR, "Exception whilst shutting down: "+e);
        }
        // remove ourselves from the queue
        _queue.removeQueue(_queueID);
        _queue.stopMonitor();
    }
    
    /**
     * Method to shutdown this Data Handler. All this actually does
     * is set a flag which the main loop will see and commence shutting
     * down. This method will return before the main loop stops.
     */
    public void shutdown() {
        // set the main loop to stop
        run=false;
        // if the main loop is waiting for data it won't notice the
        // above flag to stop. This bumps it out of the blocked get.
        _queue.releaseQueue(_queueID);
    }
    
    /**
     * 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---
    
    /**
     * Accessor to our Queue. The Control Handler needs to
     * get this reference to register us.
     *
     * @return a reference to our Queue
     */
    public Queue getQueue() {
        return _queue;
    }

//---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 = ClientInterfaceMain.NAME;
    
    /**
     * This holds a reference to the
     * system logger that is being used.
     */
    private Logger _logger = ReferenceManager.getInstance().getLogger();
    
    /** 
     * A hook to the inbound data from the socket
     */
    private BufferedReader _socketIn;
    
    /**
     * A hook to the outbound stream for the socket
     */
    private PrintWriter _socketOut;
    
    /**
     * A reference to the Socket connected to the client
     */
    private Socket _socket;
    
    /**
     * A reference to our Queue
     */
    private Queue _queue;
    
    /**
     * The flag that dictates whether we should be running
     */
    private boolean run;
    
    /**
     * Our queue number within our Queue
     */
    private int _queueID;
    
//---STATIC ATTRIBUTES---

}
Revision:	1.18
Committed:	Sun Sep 25 09:57:41 2005 UTC (18 years, 7 months ago) by tdb
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.17:	+4 -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
#	User	Rev	Content
1	tdb	1.14	/*
2			* i-scream central monitoring system
3	tdb	1.17	* http://www.i-scream.org
4	tdb	1.14	* 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	tdb	1.1	//---PACKAGE DECLARATION---
22	tdb	1.13	package uk.org.iscream.cms.server.clientinterface;
23	tdb	1.1
24			//---IMPORTS---
25	tdb	1.16	import uk.org.iscream.cms.util.*;
26	tdb	1.13	import uk.org.iscream.cms.server.componentmanager.*;
27			import uk.org.iscream.cms.server.core.*;
28	tdb	1.1	import java.net.Socket;
29			import java.io.InputStream;
30			import java.io.OutputStream;
31			import java.io.IOException;
32			import java.io.BufferedReader;
33			import java.io.PrintWriter;
34			import java.io.InputStreamReader;
35
36			/**
37	tdb	1.6	* Acts as a Data Handler to a TCP based client, providing
38			* it with a constant stream of XML data for the hosts the
39			* client has requested.
40	tdb	1.1	*
41	tdb	1.14	* @author $Author: tdb $
42	tdb	1.18	* @version $Id: TCPDataHandler.java,v 1.17 2004/08/01 10:40:48 tdb Exp $
43	tdb	1.1	*/
44	tdb	1.2	class TCPDataHandler extends Thread {
45	tdb	1.1
46			//---FINAL ATTRIBUTES---
47
48			/**
49			* The current CVS revision of this class
50			*/
51	tdb	1.18	public final String REVISION = "$Revision: 1.17 $";
52	tdb	1.1
53			//---STATIC METHODS---
54
55			//---CONSTRUCTORS---
56	tdb	1.6
57			/**
58			* Construct a new TCPDataHandler with a Socket provided
59			* by the Control Handler.
60			*
61			* @param socket The socket to which the Client has connected
62			* @throws IOException if something goes wrong, the Control Handler can deal with it
63			*/
64	tdb	1.4	public TCPDataHandler(Socket socket) throws IOException {
65	tdb	1.10	// set the Thread name
66			setName("clientinterface.TCPDataHandler");
67
68	tdb	1.12	ConfigurationProxy cp = ConfigurationProxy.getInstance();
69			String configName = "ClientInterface";
70			// see if this Queue needs a size limit
71			try {
72			int queueSizeLimit = Integer.parseInt(cp.getProperty(configName, "Queue.SizeLimit"));
73			String queueRemoveAlgorithm = cp.getProperty(configName, "Queue.RemoveAlgorithm");
74			int algorithm = StringUtils.getStringPos(queueRemoveAlgorithm, Queue.algorithms);
75			if(algorithm != -1) {
76			_logger.write(toString(), Logger.DEBUG, "Starting Queue with size limit of "+queueSizeLimit+", using remove algorithm "+queueRemoveAlgorithm);
77			// we have valid values, so lets start it.
78			_queue = new Queue(queueSizeLimit, algorithm);
79			}
80			else {
81			_logger.write(toString(), Logger.WARNING, "Bad Queue Algorithm configuration, not known: "+queueRemoveAlgorithm);
82			// just don't activate a limit
83			_queue = new Queue();
84			}
85
86			} catch (PropertyNotFoundException e) {
87			_logger.write(toString(), Logger.DEBUG, "Optional config not set: "+e);
88			// just don't activate a limit
89			_queue = new Queue();
90			} catch (NumberFormatException e) {
91			_logger.write(toString(), Logger.WARNING, "Bad Queue SizeLimit configuration: "+e);
92			// just don't activate a limit
93			_queue = new Queue();
94			}
95
96	tdb	1.1	_socket = socket;
97	tdb	1.6	// setup the reader and writer
98	tdb	1.1	_socketIn = new BufferedReader(new InputStreamReader(_socket.getInputStream()));
99	tdb	1.8	_socketOut = new PrintWriter(_socket.getOutputStream(), true);
100	tdb	1.1	_logger.write(toString(), Logger.SYSINIT, "created");
101			}
102
103			//---PUBLIC METHODS---
104	tdb	1.6	/**
105			* Main loop for the Data Handler, keeps sending data from
106			* it's local Queue.
107			*/
108	tdb	1.2	public void run() {
109			run = true;
110	tdb	1.5	_queueID = _queue.getQueue();
111	tdb	1.6	// run until we get told to stop
112	tdb	1.2	while(run) {
113	tdb	1.6	// get some data, and send some data
114	tdb	1.2	try {
115	tdb	1.5	String xml = (String) _queue.get(_queueID);
116	tdb	1.7	// if we're shutting down and we've been "bumped"
117			// it's likely we'll get a null back, and we don't
118			// want to send that on to the Client
119			if(xml != null) {
120	tdb	1.18	_socketOut.print(xml + "\n");
121			_socketOut.flush();
122	tdb	1.7	}
123	tdb	1.2	}
124			catch(InvalidQueueException e) {
125			run = false;
126			_logger.write(toString(), Logger.ERROR, "Queue failure: "+e);
127			}
128			}
129	tdb	1.6	// if we get here we've been told to stop
130	tdb	1.1	_logger.write(toString(), Logger.SYSMSG, "Shutting Down");
131	tdb	1.6	// shut down the reader, writer and Socket
132	tdb	1.2	try {
133			_socketOut.close();
134			_socketIn.close();
135			_socket.close();
136			}
137			catch(IOException e) {
138			_logger.write(toString(), Logger.ERROR, "Exception whilst shutting down: "+e);
139			}
140	tdb	1.6	// remove ourselves from the queue
141	tdb	1.5	_queue.removeQueue(_queueID);
142	tdb	1.9	_queue.stopMonitor();
143	tdb	1.2	}
144	tdb	1.6
145			/**
146			* Method to shutdown this Data Handler. All this actually does
147			* is set a flag which the main loop will see and commence shutting
148			* down. This method will return before the main loop stops.
149			*/
150	tdb	1.2	public void shutdown() {
151	tdb	1.6	// set the main loop to stop
152	tdb	1.2	run=false;
153	tdb	1.6	// if the main loop is waiting for data it won't notice the
154			// above flag to stop. This bumps it out of the blocked get.
155	tdb	1.5	_queue.releaseQueue(_queueID);
156	tdb	1.1	}
157
158			/**
159			* Overrides the {@link java.lang.Object#toString() Object.toString()}
160			* method to provide clean logging (every class should have this).
161			*
162	tdb	1.16	* This uses the uk.org.iscream.cms.util.NameFormat class
163	tdb	1.1	* to format the toString()
164			*
165			* @return the name of this class and its CVS revision
166			*/
167			public String toString() {
168			return FormatName.getName(
169			_name,
170			getClass().getName(),
171			REVISION);
172			}
173
174			//---PRIVATE METHODS---
175
176			//---ACCESSOR/MUTATOR METHODS---
177	tdb	1.6
178			/**
179			* Accessor to our Queue. The Control Handler needs to
180			* get this reference to register us.
181			*
182			* @return a reference to our Queue
183			*/
184	tdb	1.4	public Queue getQueue() {
185			return _queue;
186			}
187
188	tdb	1.1	//---ATTRIBUTES---
189
190			/**
191			* This is the friendly identifier of the
192			* component this class is running in.
193			* eg, a Filter may be called "filter1",
194			* If this class does not have an owning
195			* component, a name from the configuration
196			* can be placed here. This name could also
197			* be changed to null for utility classes.
198			*/
199			private String _name = ClientInterfaceMain.NAME;
200
201			/**
202			* This holds a reference to the
203			* system logger that is being used.
204			*/
205			private Logger _logger = ReferenceManager.getInstance().getLogger();
206
207			/**
208			* A hook to the inbound data from the socket
209			*/
210			private BufferedReader _socketIn;
211
212			/**
213			* A hook to the outbound stream for the socket
214			*/
215			private PrintWriter _socketOut;
216
217	tdb	1.6	/**
218			* A reference to the Socket connected to the client
219			*/
220	tdb	1.1	private Socket _socket;
221	tdb	1.2
222	tdb	1.6	/**
223			* A reference to our Queue
224			*/
225	tdb	1.2	private Queue _queue;
226	tdb	1.6
227			/**
228			* The flag that dictates whether we should be running
229			*/
230	tdb	1.2	private boolean run;
231	tdb	1.6
232			/**
233			* Our queue number within our Queue
234			*/
235	tdb	1.5	private int _queueID;
236	tdb	1.1
237			//---STATIC ATTRIBUTES---
238
239			}