Java listening to Serial Port

[Chris Emerson]

Hi All,

I'm using the RXTXcomm.jar to listen to a device on a COM port in windows. The code is working and reading the data ( credit card mag strip ) but it's splitting the data into multiple inputstreams. I want all the data to come back in one shot. One swipe will hit the event listener 8 - 12 times. If all that data is concatenated together, it's all there. Here's the java code based off the example on the rxtx.org site:

import gnu.io.CommPortIdentifier;
import gnu.io.PortInUseException;
import gnu.io.SerialPort;
import gnu.io.SerialPortEvent;
import gnu.io.SerialPortEventListener;
import gnu.io.UnsupportedCommOperationException;
 
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Date;
import java.util.Enumeration;
import java.util.TooManyListenersException;
 
import com.positiveaccess.idecode.IDecode;
import com.positiveaccess.idecode.IDriversLicense;
import com.positiveaccess.idecode.IFormat;
 
/**
 * Class declaration
 * 
 * 
 * @author
 * @version 1.8, 08/03/00
 */
public class ComControl implements Runnable, SerialPortEventListener
{
   static CommPortIdentifier portId1;
 
   InputStream inputStream;
 
   byte[] totalReadBuffer = null;
 
   SerialPort serialPort1;
 
   Thread readThread;
 
   protected String divertCode = "10";
 
   static String TimeStamp;
 
   String scannedInput = "";
 
   String tempInput = "";
 
   /**
    * Method declaration
    * 
    * 
    * @param args
    * 
    * @see
    */
   public static void main(String[] args)
   {
 
      try
      {
         Enumeration ports = CommPortIdentifier.getPortIdentifiers();
         while(ports.hasMoreElements())
         {
            CommPortIdentifier port = (CommPortIdentifier) ports.nextElement();
            String type;
            switch(port.getPortType())
            {
            case CommPortIdentifier.PORT_PARALLEL:
               type = "Parallel";
               break;
            case CommPortIdentifier.PORT_SERIAL:
               type = "Serial";
               break;
            default: // / Shouldn't happen
               type = "Unknown";
               break;
            }
            System.out.println(port.getName() + ": " + type);
         }
 
         portId1 = CommPortIdentifier.getPortIdentifier("COM6");
         ComControl reader = new ComControl();
      }
 
      catch(Exception e)
      {
         TimeStamp = new java.util.Date().toString();
         System.out.println(TimeStamp + ": COM6 " + portId1);
         System.out.println(TimeStamp + ": msg1 - " + e);
      }
   };
 
   /**
    * Constructor declaration
    * 
    * 
    * @see
    */
   public ComControl()
   {
 
      try
      {
         TimeStamp = new java.util.Date().toString();
         serialPort1 = (SerialPort) portId1.open("ComControl", 2000);
         System.out.println(TimeStamp
                            + ": "
                            + portId1.getName()
                            + " opened for scanner input");
      }
      catch(PortInUseException e)
      {
      }
      try
      {
         inputStream = serialPort1.getInputStream();
      }
      catch(IOException e)
      {
         e.printStackTrace();
      }
      try
      {
         serialPort1.addEventListener(this);
      }
      catch(TooManyListenersException e)
      {
      }
      serialPort1.notifyOnDataAvailable(true);
      try
      {
 
         serialPort1.setSerialPortParams(9600,
                                         SerialPort.DATABITS_8,
                                         SerialPort.STOPBITS_1,
                                         SerialPort.PARITY_NONE);
 
         serialPort1.setDTR(false);
         serialPort1.setRTS(false);
 
      }
      catch(UnsupportedCommOperationException e)
      {
         e.printStackTrace();
      }
 
      readThread = new Thread(this);
      readThread.start();
   }
 
   /**
    * Method declaration
    * 
    * 
    * @see
    */
   public void run()
   {
      try
      {
         Thread.sleep(30000);
      }
      catch(InterruptedException e)
      {
         e.printStackTrace();
      }
   }
 
   /**
    * Method declaration
    * 
    * 
    * @param event
    * 
    * @see
    */
   public void serialEvent(SerialPortEvent event)
   {
      switch(event.getEventType())
      {
      case SerialPortEvent.BI:
      case SerialPortEvent.OE:
      case SerialPortEvent.FE:
      case SerialPortEvent.PE:
      case SerialPortEvent.CD:
      case SerialPortEvent.CTS:
      case SerialPortEvent.DSR:
         System.out.println("data set ready");
      case SerialPortEvent.RI:
      case SerialPortEvent.OUTPUT_BUFFER_EMPTY:
         System.out.println("empty");
         break;
      case SerialPortEvent.DATA_AVAILABLE:
         TimeStamp = new java.util.Date().toString();
         System.out.println("*DATA avail: " + TimeStamp);
 
         try
         {
            System.out.println("count: " + inputStream.available());
            byte[] readBuffer = new byte[inputStream.available()];
            while(inputStream.available() > 0)
            {
               int numBytes = inputStream.read(readBuffer);
            }
            totalReadBuffer = readBuffer;
            System.out.print(new String(readBuffer));
         }
         catch(IOException e)
         {
         }
         catch(Exception ex)
         {
            ex.printStackTrace();
         }
         break;
      }
      System.out.println("end of event");
   }
}

[ October 15, 2008: Message edited by: Chris Emerson ]

[Rob Prime]

Please Use Code Tags to preserve your formatting.

[Chris Emerson]

This was resolved by putting a Thread.sleep(1000); as the first line of the try block inside the serialEvent method above.