import java.io.*;
import java.util.*;
import javax.comm.*;

public class GarNMEA2 implements SerialPortEventListener {

//*** experiment with rs232 serial input

   private InputStream        inputStream;
   private SerialPort         sPort;

   private int                bcount = 0;

   static OutputStreamWriter  outW = null;
   static CommPortIdentifier  portId;
   static Enumeration         portList;

   public static final String FILENAME = "nmeaout.txt";
   public static final String PORTNAME = "COM1";
   public static final int    BAUDRATE = 4800;
   public static final int    TIMEOUT  = 2000;       //*** 2 seconds

   public static void main(String[] args) {

      GarNMEA2 g = new GarNMEA2();
      g.mymain();               //*** real work done here  <===========<<<<<
   }//*** endmain

   void mymain(){

//*** open output file

       try {
          outW = new OutputStreamWriter(
                 new FileOutputStream (FILENAME));
       }
       catch (IOException e) {
          System.err.println("Output file not opened\n" + e.toString());
          System.exit(1);
       } 

//*** find the port and make the serial reader

        portList = CommPortIdentifier.getPortIdentifiers();

        while (portList.hasMoreElements()) {
            portId = (CommPortIdentifier) portList.nextElement();
            if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
                if (portId.getName().equals(PORTNAME)) {

//*****************************************************************************
//*** open port, listen, set parms

        try   {sPort = (SerialPort) portId.open("GarApp", TIMEOUT);} 
        catch (PortInUseException e) {}

        try   {inputStream = sPort.getInputStream();} 
        catch (IOException e) {}

	try   {sPort.addEventListener(this);} 
        catch (TooManyListenersException e) {}

        sPort.notifyOnDataAvailable(true);
        try {
           sPort.setSerialPortParams(BAUDRATE,
                          SerialPort.DATABITS_8,
                          SerialPort.STOPBITS_1,
                          SerialPort.PARITY_NONE);
           } 
        catch (UnsupportedCommOperationException e) {}
//*****************************************************************************

                }
            }
        }//***endWhile

   }//*** end mymain

   public void serialEvent(SerialPortEvent event) {

//*** handle serial port events, echo the data to screen

      int  newData = 0;
      char mybyte;

      switch(event.getEventType()) {
         case SerialPortEvent.BI:             //*** break
         case SerialPortEvent.OUTPUT_BUFFER_EMPTY:
            break;

//*** read data until -1 is returned  (forever)

	 case SerialPortEvent.DATA_AVAILABLE:
            while(newData != -1) {
               try {
                  newData = inputStream.read();
	          if (newData == -1) {break;}
                  mybyte = (char)newData;
                  outW.write(mybyte);
//*************** System.out.print(""+mybyte);   //*** echo to screen (debug)
                  bcount = bcount + 1;
                  if(mybyte == '$') {System.out.print("\r"+bcount+" bytes");}
               } catch(IOException ex) {
                  System.err.println(ex);
                  return;
               }
            }//***endWhile
            break;
      }//***endSwitch
   }
}//***endclass