使用Java从串口读取文件

import gnu.io.CommPortIdentifier;
import gnu.io.SerialPort;
import gnu.io.SerialPortEvent;
import gnu.io.SerialPortEventListener;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Enumeration;

public class SerialPortReader implements SerialPortEventListener {
    SerialPort serialPort;
    /** The port we're normally going to use. */
    private static final String PORT_NAMES[] = { 
        "/dev/ttyUSB0", // Linux: USB serial 
    };
    /**
    * A BufferedWriter which is used to write to the file.
    */
    private BufferedWriter writer;

    public void initialize() {
        // the following line is for RXTX
        System.setProperty("gnu.io.rxtx.SerialPorts", "/dev/ttyUSB0");

        CommPortIdentifier portId = null;
        Enumeration portEnum = CommPortIdentifier.getPortIdentifiers();

        //First, Find an instance of CommPortIdentifier that represents the port you want to open.
        while (portEnum.hasMoreElements()) {
            CommPortIdentifier currPortId = (CommPortIdentifier) portEnum.nextElement();
            for (String portName : PORT_NAMES) {
                if (currPortId.getName().equals(portName)) {
                    portId = currPortId;
                    break;
                }
            }
        }
        if (portId == null) {
            System.out.println("Could not find COM port.");
            return;
        }

        try {
            // open serial port, and use class name for the appName.
            serialPort = (SerialPort) portId.open(this.getClass().getName(), 2000);

            // set port parameters
            serialPort.setSerialPortParams(9600, SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);

            // open the streams
            InputStream in = serialPort.getInputStream();
            OutputStream out = serialPort.getOutputStream();

            // add event listeners
            serialPort.addEventListener(this);
            serialPort.notifyOnDataAvailable(true);

            // write some data
            out.write('a');

            // create a BufferedWriter to write to the file
            writer = new BufferedWriter(new FileWriter("data.txt"));
        } catch (Exception e) {
            System.err.println(e.toString());
        }
    }

    /**
     * This should be called when you stop using the port.
     * This will prevent port locking on platforms like Linux.
     */
    public synchronized void close() {
        if (serialPort != null) {
            serialPort.removeEventListener();
            serialPort.close();
            serialPort = null;
        }
        try {
            // close the BufferedWriter
            writer.close();
        } catch (IOException e) {
            System.err.println(e.toString());
        }
    }

    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:
                try {
                    int data = 0;
                    // read byte-by-byte
                    while (serialPort.getInputStream().available() > 0) {
                        try {
                            data = serialPort.getInputStream().read();
                            // write the data to the BufferedWriter
                            writer.write(data);
                        } catch (IOException e) {
                            System.err.println(e.toString());
                        }
                    }
                } catch (IOException e) {
                    System.err.println(e.toString());
                }
                break;
        }
    }
}