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//---PACKAGE DECLARATION--- |
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package uk.ac.ukc.iscream.clientinterface; |
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|
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//---IMPORTS--- |
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import uk.ac.ukc.iscream.util.*; |
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import uk.ac.ukc.iscream.componentmanager.*; |
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import uk.ac.ukc.iscream.core.*; |
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import java.net.Socket; |
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import java.net.ServerSocket; |
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import java.io.InputStream; |
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import java.io.OutputStream; |
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import java.io.IOException; |
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import java.io.BufferedReader; |
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import java.io.PrintWriter; |
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import java.io.InputStreamReader; |
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|
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|
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/** |
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* Acts as a Control Handler to a TCP based client. |
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* |
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* @author $Author: tdb1 $ |
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* @version $Id: TCPControlHandler.java,v 1.12 2001/02/01 00:18:13 tdb1 Exp $ |
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*/ |
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class TCPControlHandler extends Thread { |
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|
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//---FINAL ATTRIBUTES--- |
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|
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/** |
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* The current CVS revision of this class |
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*/ |
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public final String REVISION = "$Revision: 1.12 $"; |
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|
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/** |
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* This is our protocol version. It is hardcoded to ensure |
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* that it doesn't get accidently changed. A change to the |
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* protocol would also require changing this classes code ! |
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*/ |
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public static final String PROTOVER = "PROTOCOL 1.1"; |
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|
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//---STATIC METHODS--- |
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|
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//---CONSTRUCTORS--- |
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|
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/** |
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* Construct a new TCPControlHandler, and setup the reader |
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* and writer for the new Socket. |
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* |
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* @param socket The Socket connected to the new Client |
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* @param packetSorter A reference to the PacketSorter in the component |
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*/ |
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public TCPControlHandler(Socket socket, PacketSorter packetSorter) throws IOException { |
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_socket = socket; |
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_packetSorter = packetSorter; |
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// setup the reader & writer |
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_socketIn = new BufferedReader(new InputStreamReader(_socket.getInputStream())); |
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_socketOut = new PrintWriter(_socket.getOutputStream(), true); |
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// set the default hostlist to "all host", for backward compatibility |
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_hostList = ""; |
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_logger.write(toString(), Logger.SYSINIT, "created"); |
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} |
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|
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//---PUBLIC METHODS--- |
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|
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/** |
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* This method initiates the thread, setting things up, and then |
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* reading commands from the Client. It handles setting up of the |
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* DataHandler, and clean shutting down. |
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*/ |
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public void run() { |
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boolean run = true; |
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// Tell the client our protocol, and ask it for it's name |
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try { |
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send(PROTOVER); |
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_clientName = _socketIn.readLine(); |
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if(_clientName==null) { |
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throw new IOException("Fatal error reading from client"); |
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} |
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sendOK(); |
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} |
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catch(IOException e) { |
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_logger.write(toString(), Logger.FATAL, "Fatal error, shutdown pending"); |
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run=false; |
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} |
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|
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_logger.write(toString(), Logger.DEBUG, "Client has connected: "+_clientName); |
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|
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// loop until we decide to shutdown (run=false) |
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while(run) { |
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try { |
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String cmd = _socketIn.readLine(); |
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if(cmd==null) { |
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throw new IOException("Fatal error reading from client"); |
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} |
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// make a decision about what to do |
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if(cmd.equals("STARTCONFIG")) { |
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// get the configuration for this client |
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Configuration myConfig = _configManager.getConfiguration("Client."+_clientName); |
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sendOK(); |
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// get properties |
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cmd = _socketIn.readLine(); |
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if(cmd==null) { |
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throw new IOException("Fatal error reading from client"); |
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} |
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// provide all the requested properties |
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while(!cmd.equals("ENDCONFIG")) { |
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// client is restricted to this properties |
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if(cmd.startsWith("Client.") || cmd.startsWith("Host.")) { |
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try { |
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String returnedProperty = myConfig.getProperty(cmd); |
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send(returnedProperty); |
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} |
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catch (org.omg.CORBA.MARSHAL e) { |
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sendERROR(); |
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} |
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} |
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else { |
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sendERROR(); |
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} |
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cmd = _socketIn.readLine(); |
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if(cmd==null) { |
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throw new IOException("Fatal error reading from client"); |
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} |
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} |
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sendOK(); |
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_logger.write(toString(), Logger.DEBUG, "Client has been configured"); |
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|
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} |
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else if(cmd.equals("STARTDATA")) { |
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// if we don't have a DataHandler, set one up |
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if(_dataHandler == null) { |
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// create a serversocket |
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ServerSocket ss = new ServerSocket(0); |
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// get the port |
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String port = new Integer(ss.getLocalPort()).toString(); |
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// tell the client the port |
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send(port); |
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// wait for the client to connect |
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Socket s = ss.accept(); |
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// when we get the Socket back, give it to the data thread |
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TCPDataHandler dh = new TCPDataHandler(s); |
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// register the DataHandler's queue, giving the host list |
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_packetSorter.register(dh.getQueue(), _hostList); |
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// start up the DataHandler |
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dh.start(); |
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// Hold a reference to the DataHandler, so we can stop it later |
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_dataHandler = dh; |
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sendOK(); |
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_logger.write(toString(), Logger.DEBUG, "Data stream started at Clients Request on port: "+port); |
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} |
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else { |
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sendERROR(); |
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} |
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} |
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else if(cmd.equals("STOPDATA")) { |
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// attempt to close the data channel |
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if(closeData()) { |
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sendOK(); |
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_logger.write(toString(), Logger.DEBUG, "Data stream stopped at Clients Request"); |
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} |
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else { |
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sendERROR(); |
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} |
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} |
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else if(cmd.equals("SETHOSTLIST")) { |
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// we can only set the host list when |
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// the DataHandler is not connected |
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if(_dataHandler == null) { |
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sendOK(); |
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// read and set the host list |
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cmd = _socketIn.readLine(); |
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if(cmd==null) { |
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throw new IOException("Fatal error reading from client"); |
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} |
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_hostList = cmd; |
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sendOK(); |
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} |
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else { |
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sendERROR(); |
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} |
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} |
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else if(cmd.equals("DISCONNECT")) { |
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// we going to disconnect, so lets stop the main loop |
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run=false; |
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// if there is a DataHandler, we'd best shut it down |
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if(closeData()) { |
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_logger.write(toString(), Logger.DEBUG, "Data stream stopped at Clients Request"); |
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} |
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// say bye to the client |
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sendOK(); |
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// close the reader, writer and Socket |
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_socketIn.close(); |
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_socketOut.close(); |
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_socket.close(); |
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_logger.write(toString(), Logger.DEBUG, "Closing at Clients Request"); |
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} |
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else { |
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sendERROR(); |
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} |
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} |
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catch(IOException e) { |
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// if we get an exception, the client has probably left, so we stop |
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run=false; |
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_logger.write(toString(), Logger.FATAL, "Fatal communication error, shutdown pending"); |
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} |
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} |
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_logger.write(toString(), Logger.DEBUG, "Shutting down Control Handler, client has gone."); |
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} |
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|
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/** |
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* Overrides the {@link java.lang.Object#toString() Object.toString()} |
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* method to provide clean logging (every class should have this). |
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* |
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* This uses the uk.ac.ukc.iscream.util.NameFormat class |
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* to format the toString() |
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* |
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* @return the name of this class and its CVS revision |
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*/ |
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public String toString() { |
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return FormatName.getName( |
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_name, |
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getClass().getName(), |
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REVISION); |
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} |
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|
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//---PRIVATE METHODS--- |
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|
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/** |
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* Attempt to close down the DataHandler. This will return |
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* true if it managed to close it down, or false if there |
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* wasn't a DataHandler to close. |
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* |
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* @return whether the channel could be closed |
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*/ |
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private boolean closeData() { |
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// if we have a DataHandler, shut it down |
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if(_dataHandler != null) { |
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// Deregister the DataHandler, giving the host list |
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_packetSorter.deregister(_dataHandler.getQueue(), _hostList); |
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// Shut down the data handler |
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_dataHandler.shutdown(); |
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// Destroy our reference, leaving it for the GC |
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_dataHandler = null; |
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return true; |
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} |
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else { |
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return false; |
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} |
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} |
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|
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/** |
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* Send an OK message to the outgoing Socket |
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*/ |
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private void sendOK() { |
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send("OK"); |
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} |
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|
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/** |
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* Send an ERROR message to the outgoing Socket. |
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*/ |
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private void sendERROR() { |
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send("ERROR"); |
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} |
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|
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/** |
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* Send any String message to the outgoing Socket. |
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* |
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* @param message The message/command to send. |
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*/ |
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private void send(String message) { |
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_socketOut.println(message); |
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} |
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|
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//---ACCESSOR/MUTATOR METHODS--- |
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|
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//---ATTRIBUTES--- |
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|
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/** |
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* This is the friendly identifier of the |
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* component this class is running in. |
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* eg, a Filter may be called "filter1", |
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* If this class does not have an owning |
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* component, a name from the configuration |
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* can be placed here. This name could also |
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* be changed to null for utility classes. |
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*/ |
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private String _name = ClientInterfaceMain.NAME; |
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|
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/** |
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* This holds a reference to the |
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* system logger that is being used. |
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*/ |
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private Logger _logger = ReferenceManager.getInstance().getLogger(); |
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|
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/** |
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* A reference to the Configuration Manager the system is using |
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*/ |
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private ConfigurationManager _configManager = ReferenceManager.getInstance().getCM(); |
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|
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/** |
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* The socket we are talking on |
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*/ |
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private Socket _socket; |
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|
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/** |
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* A hook to the inbound data from the socket |
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*/ |
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private BufferedReader _socketIn; |
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|
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/** |
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* A hook to the outbound stream for the socket |
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*/ |
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private PrintWriter _socketOut; |
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|
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/** |
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* A reference to the PacketSorter. |
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*/ |
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private PacketSorter _packetSorter; |
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|
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/** |
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* A reference to the DataHandler, if there is one |
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*/ |
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private TCPDataHandler _dataHandler; |
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|
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/** |
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* The name of the Client we're connected to |
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*/ |
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private String _clientName; |
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|
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/** |
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* The host list the Client has requested |
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*/ |
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private String _hostList; |
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|
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//---STATIC ATTRIBUTES--- |
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|
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} |
