edu.hawaii.soest.kilonalu.flntu.FLNTUSource.java Source code

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/**
 *  Copyright: 2007 Regents of the University of Hawaii and the
 *             School of Ocean and Earth Science and Technology
 *    Purpose: To convert a WetLabs ECO FLNTU ASCII data source into RBNB Data Turbine
 *             frames for archival and realtime access.
 *    Authors: Christopher Jones
 *
 * $HeadURL$
 * $LastChangedDate$
 * $LastChangedBy$
 * $LastChangedRevision$
 *
 * 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 edu.hawaii.soest.kilonalu.flntu;

import com.rbnb.sapi.ChannelMap;
import com.rbnb.sapi.Source;
import com.rbnb.sapi.SAPIException;

import java.lang.StringBuffer;

import java.io.PrintWriter;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.DataInputStream;
import java.io.IOException;

import java.net.InetSocketAddress;
import java.net.UnknownHostException;

import java.nio.ByteBuffer;
import java.nio.channels.SocketChannel;

import org.apache.commons.cli.Options;
import org.apache.commons.cli.CommandLine;

import org.apache.commons.codec.binary.Hex;
import org.apache.commons.codec.DecoderException;

import org.apache.log4j.Logger;
import org.apache.log4j.BasicConfigurator;
import org.apache.log4j.PropertyConfigurator;

import org.nees.rbnb.RBNBBase;
import org.nees.rbnb.RBNBSource;

/**
 * A simple class used to harvest a decimal ASCII data stream from a WetLabs 
 * ECO FLNTU fluorometry/turbidity sensor over a TCP socket connection to a
 * serial2ip converter host. The data stream is then converted into RBNB frames 
 * and pushed into the RBNB DataTurbine real time server.  This class extends 
 * org.nees.rbnb.RBNBSource, which in turn extends org.nees.rbnb.RBNBBase, 
 * and therefore follows the API conventions found in the org.nees.rbnb code.  
 *
 * The parsing of the data stream relies on the premise that each sample of data
 * is a tab delimited string of values, and that each sample is terminated
 * by a newline character (\n). Sample sets are delimited by 'mvs 1' and 'mvs 0'.
 *
 * Example data:
 *
 * mvs 1
 * 04/07/09   15:25:06   695   88   700   84   545
 * 04/07/09   15:25:08   695   71   700   79   545
 * 04/07/09   15:25:10   695   78   700   78   544
 * 04/07/09   15:25:12   695   77   700   78   544
 * 04/07/09   15:25:14   695   72   700   76   544
 * 04/07/09   15:25:16   695   71   700   75   544
 * 04/07/09   15:25:18   695   74   700   77   543
 * 04/07/09   15:25:20   695   74   700   76   543
 * 04/07/09   15:25:22   695   72   700   72   543
 * 04/07/09   15:25:24   695   72   700   77   544
 * mvs 0
 * mvs 1
 * 04/07/09   15:25:56   695   70   700   76   545
 * 04/07/09   15:25:58   695   69   700   82   544
 * 04/07/09   15:26:00   695   71   700   83   544
 * 04/07/09   15:26:02   695   75   700   79   544
 * 04/07/09   15:26:04   695   76   700   80   544
 * 04/07/09   15:26:06   695   72   700   77   544
 * 04/07/09   15:26:08   695   71   700   76   544
 * 04/07/09   15:26:10   695   69   700   79   544
 * 04/07/09   15:26:12   695   71   700   81   543
 * 04/07/09   15:26:14   695   74   700   87   543
 * mvs 0 
 */
public class FLNTUSource extends RBNBSource {

    /*
     *  A default archive mode for the given source connection to the RBNB server.
     * Valid modes include 'append', 'create', 'load' and 'none'.
     */
    private final String DEFAULT_ARCHIVE_MODE = "append";

    /*
     * The mode in which the source interacts with the RBNB archive. Valid modes 
     * include 'append', 'create', 'load' and 'none', however, Kilo Nalu 
     * instruments should append to an archive, which will create one if none 
     * exist.
     *
     * @see setArchiveMode()
     * @see getArchiveMode()
     */
    private String archiveMode = DEFAULT_ARCHIVE_MODE;

    /*
     * The default size of the ByteBuffer used to beffer the TCP stream from the
     * source instrument.
     */
    private int DEFAULT_BUFFER_SIZE = 8096; // 8K

    /**
     * The size of the ByteBuffer used to beffer the TCP stream from the 
     * instrument.
     */
    private int bufferSize = DEFAULT_BUFFER_SIZE;

    /*
     *  A default RBNB channel name for the given source instrument
     */
    private String DEFAULT_RBNB_CHANNEL = "DecimalASCIISampleData";

    /**
     * The name of the RBNB channel for this data stream
     */
    private String rbnbChannelName = DEFAULT_RBNB_CHANNEL;

    /*
     *  A default source IP address for the given source instrument
     */
    private final String DEFAULT_SOURCE_HOST_NAME = "localhost";

    /**
     * The domain name or IP address of the host machine that this Source 
     * represents and from which the data will stream. 
     */
    private String sourceHostName = DEFAULT_SOURCE_HOST_NAME;

    /*
     *  A default source TCP port for the given source instrument
     */
    private final int DEFAULT_SOURCE_HOST_PORT = 2101;

    /**
     * The TCP port to connect to on the Source host machine 
     */
    private int sourceHostPort = DEFAULT_SOURCE_HOST_PORT;

    /**
     * The number of bytes in the ensemble as each byte is read from the stream
     */
    private int sampleByteCount = 0;

    /**
     * The default log configuration file location
     */
    private final String DEFAULT_LOG_CONFIGURATION_FILE = "lib/log4j.properties";

    /**
     * The log configuration file location
     */
    private String logConfigurationFile = DEFAULT_LOG_CONFIGURATION_FILE;

    /**
     * The Logger instance used to log system messages 
     */
    private static Logger logger = Logger.getLogger(FLNTUSource.class);

    protected int state = 0;

    private boolean readyToStream = false;

    private Thread streamingThread;

    /*
     * An internal Thread setting used to specify how long, in milliseconds, the
     * execution of the data streaming Thread should wait before re-executing
     * 
     * @see execute()
     */
    private final int RETRY_INTERVAL = 5000;

    /**
     * Constructor - create an empty instance of the FLNTUSource object, using
     * default values for the RBNB server name and port, source instrument name
     * and port, archive mode, archive frame size, and cache frame size. 
     */

    public FLNTUSource() {
    }

    /**
     * Constructor - create an instance of the FLNTUSource object, using the
     * argument values for the source instrument name and port, and the RBNB 
     * server name and port.  This constructor will use default values for the
     * archive mode, archive frame size, and cache frame size. 
     *
     * @param sourceHostName  the name or IP address of the source instrument
     * @param sourceHostPort  the TCP port of the source host instrument
     * @param serverName      the name or IP address of the RBNB server connection
     * @param serverPort      the TCP port of the RBNB server
     */
    public FLNTUSource(String sourceHostName, String sourceHostPort, String serverName, String serverPort) {

        setHostName(sourceHostName);
        setHostPort(Integer.parseInt(sourceHostPort));
        setServerName(serverName);
        setServerPort(Integer.parseInt(serverPort));
    }

    /**
     * Constructor - create an instance of the FLNTUSource object, using the
     * argument values for the source instrument name and port, and the RBNB 
     * server name and port, the archive mode, archive frame size, and cache 
     * frame size.  A frame is created at each call to flush() to an RBNB server,
     * and so the frame sizes below are relative to the number of bytes of data
     * loaded in the ChannelMap that is flushed to the RBNB server.
     *
     * @param sourceHostName   the name or IP address of the source instrument
     * @param sourceHostPort   the TCP port of the source host instrument
     * @param serverName       the name or IP address of the RBNB server 
     * @param serverPort       the TCP port of the RBNB server
     * @param archiveMode      the RBNB archive mode: append, load, create, none
     * @param archiveFrameSize the size, in frames, for the RBNB server to archive
     * @param cacheFrameSize   the size, in frames, for the RBNB server to cache
     * @param rbnbClientName   the unique name of the source RBNB client
     */
    public FLNTUSource(String sourceHostName, String sourceHostPort, String serverName, String serverPort,
            String archiveMode, int archiveFrameSize, int cacheFrameSize, String rbnbClientName) {

        setHostName(sourceHostName);
        setHostPort(Integer.parseInt(sourceHostPort));
        setServerName(serverName);
        setServerPort(Integer.parseInt(serverPort));
        setArchiveMode(archiveMode);
        setArchiveSize(archiveFrameSize);
        setCacheSize(cacheFrameSize);
        setRBNBClientName(rbnbClientName);
    }

    /**
     * A method that executes the streaming of data from the source to the RBNB
     * server after all configuration of settings, connections to hosts, and
     * thread initiatizing occurs.  This method contains the detailed code for 
     * streaming the data and interpreting the stream.
     */
    protected boolean execute() {
        logger.debug("FLNTUSource.execute() called.");
        // do not execute the stream if there is no connection
        if (!isConnected())
            return false;

        boolean failed = false;

        SocketChannel socket = getSocketConnection();

        // while data are being sent, read them into the buffer
        try {
            // create four byte placeholders used to evaluate up to a four-byte 
            // window.  The FIFO layout looks like:
            //           -------------------------
            //   in ---> | One | Two |Three|Four |  ---> out
            //           -------------------------
            byte byteOne = 0x00, // set initial placeholder values
                    byteTwo = 0x00, byteThree = 0x00, byteFour = 0x00;

            // Create a buffer that will store the sample bytes as they are read
            ByteBuffer sampleBuffer = ByteBuffer.allocate(getBufferSize());

            // create a byte buffer to store bytes from the TCP stream
            ByteBuffer buffer = ByteBuffer.allocateDirect(getBufferSize());

            // add a channel of data that will be pushed to the server.  
            // Each sample will be sent to the Data Turbine as an rbnb frame.
            ChannelMap rbnbChannelMap = new ChannelMap();

            // while there are bytes to read from the socket ...
            while (socket.read(buffer) != -1 || buffer.position() > 0) {

                // prepare the buffer for reading
                buffer.flip();

                // while there are unread bytes in the ByteBuffer
                while (buffer.hasRemaining()) {
                    byteOne = buffer.get();
                    logger.debug("char: " + (char) byteOne + "\t" + "b1: "
                            + new String(Hex.encodeHex((new byte[] { byteOne }))) + "\t" + "b2: "
                            + new String(Hex.encodeHex((new byte[] { byteTwo }))) + "\t" + "b3: "
                            + new String(Hex.encodeHex((new byte[] { byteThree }))) + "\t" + "b4: "
                            + new String(Hex.encodeHex((new byte[] { byteFour }))) + "\t" + "sample pos: "
                            + sampleBuffer.position() + "\t" + "sample rem: " + sampleBuffer.remaining() + "\t"
                            + "sample cnt: " + sampleByteCount + "\t" + "buffer pos: " + buffer.position() + "\t"
                            + "buffer rem: " + buffer.remaining() + "\t" + "state: " + state);

                    // Use a State Machine to process the byte stream.
                    switch (state) {

                    case 0:

                        // sample sets begin with 'mvs 1\r\n' and end with 'mvs 0\r\n'.  Find the 
                        // beginning of the sample set using the 4-byte window (s 1\r\n)
                        // note bytes are in reverse order in the FIFO window
                        if (byteOne == 0x0A && byteTwo == 0x0D && byteThree == 0x31 && byteFour == 0x20) {
                            // we've found the beginning of a sample set, move on
                            state = 1;
                            break;

                        } else {
                            break;
                        }

                    case 1: // read the rest of the bytes to the next EOL characters

                        // sample line is terminated by record delimiter byte (\r\n)
                        // note bytes are in reverse order in the FIFO window
                        if (byteOne == 0x0A && byteTwo == 0x0D && byteThree == 0x30 && byteFour == 0x20) {

                            // we've found the sample set ending, clear buffers and return
                            // to state 0 to wait for the next set
                            byteOne = 0x00;
                            byteTwo = 0x00;
                            byteThree = 0x00;
                            byteFour = 0x00;
                            sampleBuffer.clear();
                            sampleByteCount = 0;
                            rbnbChannelMap.Clear();
                            logger.debug("Cleared b1,b2,b3,b4. Cleared sampleBuffer. Cleared rbnbChannelMap.");
                            state = 0;

                            // if we're not at the sample set end, look for individual samples    
                        } else if (byteOne == 0x0A && byteTwo == 0x0D) {

                            // found the sample ending delimiter
                            // add in the sample delimiter to the sample buffer
                            if (sampleBuffer.remaining() > 0) {
                                sampleBuffer.put(byteOne);
                                sampleByteCount++;
                            } else {
                                sampleBuffer.compact();
                                logger.debug("Compacting sampleBuffer ...");
                                sampleBuffer.put(byteOne);
                                sampleByteCount++;

                            }

                            // extract just the length of the sample bytes out of the
                            // sample buffer, and place it in the channel map as a 
                            // byte array.  Then, send it to the data turbine.
                            byte[] sampleArray = new byte[sampleByteCount];
                            sampleBuffer.flip();
                            sampleBuffer.get(sampleArray);

                            // send the sample to the data turbine
                            rbnbChannelMap.PutTimeAuto("server");
                            String sampleString = new String(sampleArray, "US-ASCII");
                            int channelIndex = rbnbChannelMap.Add(getRBNBChannelName());
                            rbnbChannelMap.PutMime(channelIndex, "text/plain");
                            rbnbChannelMap.PutDataAsString(channelIndex, sampleString);
                            getSource().Flush(rbnbChannelMap);
                            logger.info("Sample: " + sampleString.substring(0, sampleString.length() - 2)
                                    + " sent data to the DataTurbine. ");
                            byteOne = 0x00;
                            byteTwo = 0x00;
                            byteThree = 0x00;
                            byteFour = 0x00;
                            sampleBuffer.clear();
                            sampleByteCount = 0;
                            rbnbChannelMap.Clear();
                            logger.debug("Cleared b1,b2,b3,b4. Cleared sampleBuffer. Cleared rbnbChannelMap.");
                            break;

                        } else { // not 0x0

                            // still in the middle of the sample, keep adding bytes
                            sampleByteCount++; // add each byte found

                            if (sampleBuffer.remaining() > 0) {
                                sampleBuffer.put(byteOne);
                            } else {
                                sampleBuffer.compact();
                                logger.debug("Compacting sampleBuffer ...");
                                sampleBuffer.put(byteOne);

                            }

                            break;
                        } // end if for 0x0D20 EOL

                    } // end switch statement

                    // shift the bytes in the FIFO window
                    byteFour = byteThree;
                    byteThree = byteTwo;
                    byteTwo = byteOne;

                } //end while (more unread bytes)

                // prepare the buffer to read in more bytes from the stream
                buffer.compact();

            } // end while (more socket bytes to read)
            socket.close();

        } catch (IOException e) {
            // handle exceptions
            // In the event of an i/o exception, log the exception, and allow execute()
            // to return false, which will prompt a retry.
            failed = true;
            e.printStackTrace();
            return !failed;
        } catch (SAPIException sapie) {
            // In the event of an RBNB communication  exception, log the exception, 
            // and allow execute() to return false, which will prompt a retry.
            failed = true;
            sapie.printStackTrace();
            return !failed;
        }

        return !failed;
    } // end if (  !isConnected() ) 

    /**
    * A method used to the TCP socket of the remote source host for communication
    * @param host       the name or IP address of the host to connect to for the
    *                   socket connection (reading)
    * @param portNumber the number of the TCP port to connect to (i.e. 2604)
    */
    protected SocketChannel getSocketConnection() {

        String host = getHostName();
        int portNumber = new Integer(getHostPort()).intValue();
        SocketChannel dataSocket = null;

        try {

            // create the socket channel connection to the data source via the 
            // converter serial2IP converter      
            dataSocket = SocketChannel.open();
            dataSocket.connect(new InetSocketAddress(host, portNumber));

            // if the connection to the source fails, also disconnect from the RBNB
            // server and return null
            if (!dataSocket.isConnected()) {
                dataSocket.close();
                disconnect();
                dataSocket = null;
            }
        } catch (UnknownHostException ukhe) {
            System.err.println("Unable to look up host: " + host + "\n");
            disconnect();
            dataSocket = null;
        } catch (IOException nioe) {
            System.err.println("Couldn't get I/O connection to: " + host);
            disconnect();
            dataSocket = null;
        } catch (Exception e) {
            disconnect();
            dataSocket = null;
        }
        return dataSocket;

    }

    /**
     * A method that sets the size, in bytes, of the ByteBuffer used in streaming 
     * data from a source instrument via a TCP connection
     */
    public int getBufferSize() {
        return this.bufferSize;
    }

    /**
     * A method that returns the domain name or IP address of the source 
     * instrument (i.e. the serial-to-IP converter to which it is attached)
     */
    public String getHostName() {
        return this.sourceHostName;
    }

    /**
     * A method that gets the log configuration file location
     *
     * @return logConfigurationFile  the log configuration file location
     */
    public String getLogConfigurationFile() {
        return this.logConfigurationFile;
    }

    /**
     * A method that returns the name of the RBNB channel that contains the 
     * streaming data from this instrument
     */
    public String getRBNBChannelName() {
        return this.rbnbChannelName;
    }

    /**
     * A method that returns the TCP port of the source 
     * instrument (i.e. the serial-to-IP converter to which it is attached)
     */
    public int getHostPort() {
        return this.sourceHostPort;
    }

    /**
     * A method that returns the versioning info for this file.  In this case, 
     * it returns a String that includes the Subversion LastChangedDate, 
     * LastChangedBy, LastChangedRevision, and HeadURL fields.
     */

    public String getCVSVersionString() {
        return ("$LastChangedDate$" + "$LastChangedBy$" + "$LastChangedRevision$" + "$HeadURL$");
    }

    /**
     * A method that returns true if the RBNB connection is established
     * and if the data streaming Thread has been started
     */
    public boolean isRunning() {
        // return the connection status and the thread status
        return (isConnected() && readyToStream);
    }

    /**
     * The main method for running the code
     * @ param args[] the command line list of string arguments, none are needed
     */

    public static void main(String args[]) {

        try {
            // create a new instance of the FLNTUSource object, and parse the command 
            // line arguments as settings for this instance
            final FLNTUSource tChainSource = new FLNTUSource();

            // parse the commandline arguments to configure the connection, then 
            // start the streaming connection between the source and the RBNB server.
            if (tChainSource.parseArgs(args)) {

                // Set up a simple logger that logs to the console
                PropertyConfigurator.configure(tChainSource.getLogConfigurationFile());
                logger.info("FLNTUSource.main() called.");

                tChainSource.start();
            }

            // Handle ctrl-c's and other abrupt death signals to the process
            Runtime.getRuntime().addShutdownHook(new Thread() {
                // stop the streaming process
                public void run() {
                    tChainSource.stop();
                }
            });

        } catch (Exception e) {
            logger.info("Error in main(): " + e.getMessage());
            e.printStackTrace();
        }
    }

    /*
     * A method that runs the data streaming work performed by the execute()
     * by handling execution problems and continuously trying to re-execute after 
     * a specified retry interval for the thread.
     */
    private void runWork() {

        // handle execution problems by retrying if execute() fails
        boolean retry = true;

        while (retry) {

            // connect to the RBNB server
            if (connect()) {
                // run the data streaming code
                retry = !execute();
            }

            disconnect();

            if (retry) {
                try {
                    Thread.sleep(RETRY_INTERVAL);
                } catch (Exception e) {
                    logger.info("There was an execution problem. Retrying. Message is: " + e.getMessage());
                }
            }
        }
        // stop the streaming when we are done
        stop();
    }

    /**
     * A method that sets the command line arguments for this class.  This method 
     * calls the <code>RBNBSource.setBaseArgs()</code> method.
     * 
     * @param command  The CommandLine object being passed in from the command
     */
    protected boolean setArgs(CommandLine command) {

        // first set the base arguments that are included on the command line
        if (!setBaseArgs(command)) {
            return false;
        }

        // add command line arguments here

        // handle the -H option
        if (command.hasOption("H")) {
            String hostName = command.getOptionValue("H");
            if (hostName != null) {
                setHostName(hostName);
            }
        }

        // handle the -P option, test if it's an integer
        if (command.hasOption("P")) {
            String hostPort = command.getOptionValue("P");
            if (hostPort != null) {
                try {
                    setHostPort(Integer.parseInt(hostPort));

                } catch (NumberFormatException nfe) {
                    logger.info("Error: Enter a numeric value for the host port. " + hostPort
                            + " is not a valid number.");
                    return false;
                }
            }
        }

        // handle the -C option
        if (command.hasOption("C")) {
            String channelName = command.getOptionValue("C");
            if (channelName != null) {
                setChannelName(channelName);
            }
        }

        return true;
    }

    /**
     * A method that sets the size, in bytes, of the ByteBuffer used in streaming 
     * data from a source instrument via a TCP connection
     *
     * @param bufferSize  the size, in bytes, of the ByteBuffer
     */
    public void setBuffersize(int bufferSize) {
        this.bufferSize = bufferSize;
    }

    /**
     * A method that sets the log configuration file name
     *
     * @param logConfigurationFile  the log configuration file name
     */
    public void setLogConfigurationFile(String logConfigurationFile) {
        this.logConfigurationFile = logConfigurationFile;
    }

    /**
     * A method that sets the RBNB channel name of the source instrument's data
     * stream
     *
     * @param channelName  the name of the RBNB channel being streamed
     */
    public void setChannelName(String channelName) {
        this.rbnbChannelName = channelName;
    }

    /**
     * A method that sets the domain name or IP address of the source 
     * instrument (i.e. the serial-to-IP converter to which it is attached)
     *
     * @param hostName  the domain name or IP address of the source instrument
     */
    public void setHostName(String hostName) {
        this.sourceHostName = hostName;
    }

    /**
     * A method that sets the TCP port of the source 
     * instrument (i.e. the serial-to-IP converter to which it is attached)
     *
     * @param hostPort  the TCP port of the source instrument
     */
    public void setHostPort(int hostPort) {
        this.sourceHostPort = hostPort;
    }

    /**
     * A method that sets the command line options for this class.  This method 
     * calls the <code>RBNBSource.setBaseOptions()</code> method in order to set
     * properties such as the sourceHostName, sourceHostPort, serverName, and
     * serverPort.
     */
    protected Options setOptions() {
        Options options = setBaseOptions(new Options());

        // Note: 
        // Command line options already provided by RBNBBase include:
        // -h "Print help"
        // -s "RBNB Server Hostname"
        // -p "RBNB Server Port Number"
        // -S "RBNB Source Name"
        // -v "Print Version information"

        // Command line options already provided by RBNBSource include:
        // -z "Cache size"
        // -Z "Archive size"

        // add command line options here
        options.addOption("H", true, "Source host name or IP (defaults to " + getHostName() + ").");
        options.addOption("P", true, "Source host port number (defaults to " + getHostPort() + ").");
        options.addOption("C", true, "RBNB source channel name (defaults to " + getRBNBChannelName() + ").");
        //options.addOption("M", true, "RBNB archive mode *" + getArchiveMode());    

        return options;
    }

    /**
     * A method that starts the streaming of data from the source instrument to
     * the RBNB server via an established TCP connection.  
     */
    public boolean start() {

        // return false if the streaming is running
        if (isRunning()) {
            return false;
        }

        // reset the connection to the RBNB server
        if (isConnected()) {
            disconnect();
        }
        connect();

        // return false if the connection fails
        if (!isConnected()) {
            return false;
        }

        // begin the streaming thread to the source
        startThread();

        return true;
    }

    /**
     * A method that creates and starts a new Thread with a run() method that 
     * begins processing the data streaming from the source instrument.
     */
    private void startThread() {

        // build the runnable class and implement the run() method
        Runnable runner = new Runnable() {
            public void run() {
                runWork();
            }
        };

        // build the Thread and start it, indicating that it has been started
        readyToStream = true;
        streamingThread = new Thread(runner, "StreamingThread");
        streamingThread.start();
    }

    /**
     * A method that stops the streaming of data between the source instrument and
     * the RBNB server.  
     */
    public boolean stop() {

        // return false if the thread is not running
        if (!isRunning()) {
            return false;
        }

        // stop the thread and disconnect from the RBNB server
        stopThread();
        disconnect();
        return true;
    }

    /**
     * A method that interrupts the thread created in startThread()
     */
    private void stopThread() {
        // set the streaming status to false and stop the Thread
        readyToStream = false;
        streamingThread.interrupt();
    }

}