자바 시리얼 통신 예제

SerialEcho.java

 

import java.io.*;

import java.util.*;

import javax.comm.*;

 

public class SerialEcho implementsRunnable,SerialPortEventListener{

          static CommPortIdentifier portId;

          static Enumeration portList;

 

          BufferedReader br;

          BufferedWriter bw;

          String echoMsg;

          SerialPort serialPort;

          Thread readThread;

 

public static void main(String[] args) {

    //시스템의 모든 포트 리스트를 가져옴.

          portList = CommPortIdentifier.getPortIdentifiers();

 

          while (portList.hasMoreElements()) {

portId = (CommPortIdentifier) portList.nextElement();

//현재 포트타입이 시리얼 포트일 경우

if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL){

  // MS-windows에서 시리얼 포트 이름은“COM1”,”COM2”…

                 if (portId.getName().equals("COM1")) {

                 // if (portId.getName().equals("/dev/term/a")) {àSolaris에서

                       //시리얼 통신을 위한 포트 생성

SerialEcho reader = new SerialEcho();

                }

             }

         }

}

 

 public SerialEcho() {

             try{

               serialPort = (SerialPort) portId.open("SerialEcho", 2000);

             } catch (PortInUseException e) {}

    

       try {

           br = new BufferedReader(new                                                      InputStreamReader(serialPort.getInputStream()));

            bw = new BufferedWriter(new                                                      OutputStreamWriter(serialPort.getOutputStream()));

       } catch (IOException e) {}

          try {

         //시리얼 포트에 데이터가 수신되기를 기다림.

            serialPort.addEventListener(this);

          } catch (TooManyListenersException e) {}

 

          // input data가 들어오면 수신 통보

       serialPort.notifyOnDataAvailable(true);

try{

           serialPort.setSerialPortParams(19200,      // Baud Rate

           SerialPort.DATABITS_8,               // Data Bits

           SerialPort.STOPBITS_1,               // Stop Bits

           SerialPort.PARITY_NONE);            // Parity

       } catch (UnsupportedCommOperationException e) {}

                readThread = new Thread(this);

             readThread.start();

   }

   public void run() {

       try    {

           Thread.sleep(20000);

       } catch (InterruptedException e) {}

   }

 

public void serialEvent(SerialPortEvent event){

       switch(event.getEventType()){

            case SerialPortEvent.BI:     // Break interrupt

         case SerialPortEvent.OE:    // Overrun error

         case SerialPortEvent.FE:     // Framing error

            case SerialPortEvent.PE:    // Parity error.

            case SerialPortEvent.CD:    // Carrier detect

            case SerialPortEvent.CTS:  // Clear to send

            case SerialPortEvent.DSR:  // Data set ready

            case SerialPortEvent.RI:     // Ring indicator.

            case SerialPortEvent.OUTPUT_BUFFER_EMPTY:

                 break;            // Output buffer is empty

          

// Data available at the serial port.

            case SerialPortEvent.DATA_AVAILABLE:

                byte[] readBuffer = new byte[20];

             try{

                 while(true){

                      echoMsg = br.readLine();

                      System.out.println("Echo: " + echoMsg);

                    bw.write(echoMsg,0,echoMsg.length());

                      bw.newLine();

                      bw.flush();

                  }                              

              }catch (IOException e) {}

               break;

        }

     }

}