package  main;

 import  java.io.*;
 import  java.util.*;
 import  gnu.io.*;


 public   class  SimpleWrite {
     static  Enumeration	      portList;
     static  CommPortIdentifier portId;
     static  String	      messageString = "Hello, world!";
     static  SerialPort	      serialPort;
     static  OutputStream       outputStream;
     static  DataOutputStream    dos ;
     static   boolean 	      outputBufferEmptyFlag = false;

     public   static   void  main(String[] args) {
	 boolean  portFound = false;
	String  defaultPort = "COM3";

	 if  (args.length >  0 ) {
	    defaultPort = args[ 0 ];
	}
	portList = CommPortIdentifier.getPortIdentifiers();
	 while  (portList.hasMoreElements()) {
	    portId = (CommPortIdentifier) portList.nextElement();
        System.out.println(portId.getName());
         if  (portId.getName().equals(defaultPort)) {
		    System.out.println("Found port " + defaultPort);
		    portFound = true;
		     try  {
			serialPort =
			    (SerialPort)portId.open("SimpleWrite",  2000 );
		    }  catch  (PortInUseException e) {
			System.out.println("Port in use.");
			 continue ;
		    }
		     try  {
			outputStream = serialPort.getOutputStream();
		    }  catch  (IOException e) {}
		     try  {
			serialPort.setSerialPortParams( 9600 ,
						       SerialPort.DATABITS_8,
						       SerialPort.STOPBITS_1,
						       SerialPort.PARITY_NONE);
		    }  catch  (UnsupportedCommOperationException e) {}
		     try  {
		    	serialPort.notifyOnOutputEmpty(true);
		    }  catch  (Exception e) {
			System.out.println("Error setting event notification");
			System.out.println(e.toString());
			System.exit(- 1 );
		    }
		    System.out.println(
		    	"Writing \""+messageString+"\" to "
			+serialPort.getName());

		     try  {
			outputStream.write(messageString.getBytes());
		    }  catch  (IOException e) {}

		     try  {
		       Thread.sleep( 2000 );  // Be sure data is xferred before closing
		    }  catch  (Exception e) {}
		    serialPort.close();
		    System.exit( 1 );
		}  
	}
    }
}

 package  main;

 import  gnu.io.*;
 import  java.io.*;


 import  java.util.Enumeration;
 import  java.util.TooManyListenersException;



 public   class  COMServer  implements  Runnable, SerialPortEventListener{
     static  CommPortIdentifier portId;
     static  Enumeration	      portList;
     private  InputStream		      inputStream;
     private  SerialPort		      serialPort;
     private  Thread		      readThread;

     public  COMServer(String portName){
        System.out.println(portName +" is under control...");
         while  (true) {
             try  {
                serialPort = (SerialPort)portId.open("SimpleReadApp",  2000 );
            }  catch  (PortInUseException e1) {
                e1.printStackTrace();
            }
             try  {
                inputStream = serialPort.getInputStream();
            }  catch  (IOException e2) {
                e2.printStackTrace();
            }
             try  {
                serialPort.addEventListener( this );
            }  catch  (TooManyListenersException e3) {
                e3.printStackTrace();
            }
            serialPort.notifyOnDataAvailable(true);
             try  {
                serialPort.setSerialPortParams( 9600 , SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);
            }  catch  (UnsupportedCommOperationException e4) {
                e4.printStackTrace();
            }
            readThread =  new  Thread( this );
            readThread.start();
        }
    }

     public   void  run() {
         try  {
            Thread.sleep( 20000 );
        }  catch  (InterruptedException e) {
            e.printStackTrace();
        }
    }

     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:
             case  SerialPortEvent.RI:
             case  SerialPortEvent.OUTPUT_BUFFER_EMPTY:  break ;
             case  SerialPortEvent.DATA_AVAILABLE:
                 byte [] readBuffer =  new   byte [ 20 ];
                 try  {
                     while  (inputStream.available() >  0 ) {
                         int  numBytes = inputStream.read(readBuffer);
                    }
                    System.out.print( new  String(readBuffer));
                }  catch  (IOException e) {
                    e.printStackTrace();
                }
                 break ;
        }
    }



     public   static   void  main(String[] args) {
         boolean 	portFound = false;
        String defaultPort = "COM3";
        portList = CommPortIdentifier.getPortIdentifiers();
         while  (portList.hasMoreElements()) {
            portId = (CommPortIdentifier)portList.nextElement();
             if  (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
                 if  (portId.getName().equals(defaultPort)) {
                    System.out.println("Found port");
                    portFound = true;
                    COMServer com =  new  COMServer(defaultPort);
                }
            }
        }
    }
}