从COM端口异步读取(使用JSSC lib)

时间:2016-02-05 07:03:39

标签: java asynchronous serial-port jssc

我的项目使用JSSC库来连接PC和微控制器。

写方法:

public void write(byte[] buffer) throws SerialPortException {
    if (serialPort.isOpened())
        serialPort.writeBytes(buffer);
}

阅读方法:

public byte[] read() throws SerialPortException {

    byte[] result = null;

    FutureTask<byte[]> task = new FutureTask<>(new PortReader());
    ExecutorService executor = Executors.newSingleThreadExecutor();

    try {
        result = (byte[]) executor.submit(task).get(1000, TimeUnit.MILLISECONDS);
    } catch (InterruptedException | ExecutionException e) {
        e.printStackTrace();
    } catch (TimeoutException e) {
        System.err.println(getClass().getSimpleName() + " READ: Timeout exception!");
    }

    return result;
}

private class PortReader implements Callable<byte[]>, SerialPortEventListener {

    private byte[] data = null;

    @Override
    public void serialEvent(SerialPortEvent event) {

        if (event.isRXCHAR() && event.getEventValue() > 0) {
            try {
                data = serialPort.readBytes(event.getEventValue());
            } catch (SerialPortException e) {
                e.printStackTrace();
            }
        }
    }

    @Override
    public byte[] call() throws Exception {
        if (data == null)
            Thread.sleep(200);

        return data;
    }
}

我尝试实现同步写入(立即发送数据)到端口并从端口异步读取(等待输入数据至少1000 ms)。

这是正确的决定吗?也许还有其他异步数据读取方式?

谢谢!

1 个答案:

答案 0 :(得分:0)

最好使用serialport类中使用的等待事件。这种方式使端口等待命令被篡改。

serialPort.writeBytes(buffer);//Write data to port
serialPort.addEventListener(new PortReader(serialPort), SerialPort.MASK_RXCHAR);
int[][] eventArray=serialPort.waitEvents()
for (int i = 0; i < eventArray.length; i++) {
    if ((eventArray[i][0] > 0) ) {
     serialPort.eventListener.serialEvent(new SerialPortEvent("COM1", eventArray[i][0], eventArray[i][1])); //give your port name and the events got.
                    }
                  }