Java串口编程学习2-读串口

如果读串口出现乱码，则：

1.可能是波特率设置不对

2.可能是数据编码格式不对

import gnu.io.*;



import java.awt.*;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.WindowAdapter;

import java.awt.event.WindowEvent;

import java.io.IOException;

import java.io.InputStream;

import java.util.Enumeration;

import java.util.TooManyListenersException;



/**

 * Created by gbr on 13-12-12.

 */



class R_Frame extends Frame implements Runnable, ActionListener, SerialPortEventListener{

    static CommPortIdentifier portId;

    static Enumeration portList;

    InputStream inputStream;



    SerialPort serialPort;

    Thread readThread;

    String str = "";

    TextField out_message = new TextField("上面文本框显示接收到的数据");

    TextArea in_message = new TextArea();

    Button btnOpen = new Button("Open Comm");

    R_Frame(){

        super("串口接收数据");

        setSize(200, 200);

        setVisible(true);

        btnOpen.addActionListener(this);

        add(out_message, "South");

        add(in_message, "Center");

        add(btnOpen, "North");

    }



    public void actionPerformed(ActionEvent event){

        portList = CommPortIdentifier.getPortIdentifiers();

        while (portList.hasMoreElements()){

            portId = (CommPortIdentifier)portList.nextElement();

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

                if (portId.getName().equals("COM8")){

                    try{

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

                        out_message.setText("已经打开串口COM8，正在接收数据...");

                    } catch (PortInUseException e) {

                        out_message.setText("端口已被占用！");

                        e.printStackTrace();

                    }

                    try{

                        serialPort.addEventListener(this);

                    }catch (TooManyListenersException e){

                        out_message.setText("监听异常！");

                        e.printStackTrace();

                    }

                    serialPort.notifyOnDataAvailable(true);

                }

            }

        }

        readThread = new Thread(this);

        readThread.start();

    }

    public void run(){

        try{

            Thread.sleep(20);

        }catch (InterruptedException e){

            e.printStackTrace();

        }

    }



    public void serialEvent(SerialPortEvent event){

        try{

            serialPort.setSerialPortParams(115200,

                    SerialPort.DATABITS_8,

                    SerialPort.STOPBITS_1,

                    SerialPort.PARITY_NONE);

        }catch (UnsupportedCommOperationException e){

            e.printStackTrace();

        }



        byte[] readBuffer = new byte[200];

        try{

            inputStream = serialPort.getInputStream();

        }catch (IOException e){

            e.printStackTrace();

        }



        try{

            while (inputStream.available() > 0){

                int numBytes = inputStream.read(readBuffer);

            }

            str = new String(readBuffer);

            in_message.append( str + "\n" );

        }catch (IOException e){

            e.printStackTrace();

        }

    }

}



public class ReadComm {

    public static void main( String[] args ){

        R_Frame R_win = new R_Frame();

        R_win.addWindowListener(new WindowAdapter() {

            @Override

            public void windowClosing(WindowEvent e) {

                System.exit(0);

                //super.windowClosing(e);

            }

        });

        R_win.pack();

    }

}