能不能写一个servlet读写本地串口的数据

Question

SUN Java Communications API 2.0

Answer 1

import java.io.*;
import java.util.*;
import javax.comm.*;public class SimpleRead implements Runnable, SerialPortEventListener {
    static CommPortIdentifier portId;
    static Enumeration portList;    InputStream inputStream;
    SerialPort serialPort;
    Thread readThread;    public static void main(String[] args) {
        portList = CommPortIdentifier.getPortIdentifiers();        while (portList.hasMoreElements()) {
            portId = (CommPortIdentifier) portList.nextElement();
            if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
                if (portId.getName().equals("COM1")) {
//                if (portId.getName().equals("/dev/term/a")) {
                    SimpleRead reader = new SimpleRead();
                }
            }
        }
    }    public SimpleRead() {
        try {
            serialPort = (SerialPort) portId.open("SimpleReadApp", 2000);
        }
        catch (PortInUseException e) {}        try {
            inputStream = serialPort.getInputStream();
        }
        catch (IOException e) {}        try {
            serialPort.addEventListener(this);
        }
        catch (TooManyListenersException e) {}        serialPort.notifyOnDataAvailable(true);
        try {
            serialPort.setSerialPortParams(9600,
                                           SerialPort.DATABITS_8,
                                           SerialPort.STOPBITS_1,
                                           SerialPort.PARITY_NONE);
        }
        catch (UnsupportedCommOperationException e) {}        readThread = new Thread(this);
        readThread.start();
    }    public void run() {
        try {
            Thread.sleep(20000);
        }
        catch (InterruptedException e) {}
    }    public void serialEvent(SerialPortEvent event) {
        System.out.println("event.getEventType() : " + event.getEventType());
        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) {}
                break;
        }
    }
}

Answer 2

servlet运行在服务器端不可能读本地串口，要用签名的applet