RXTX串行连接 - 阻塞read（）的问题

本文介绍了RXTX串行连接 - 阻塞read（）的问题的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我正在尝试使用RXTX库阻止Windows上的串行通信（XP和7）。我已在两端测试了与Hyperterminal的连接，并且它完美无瑕。

I am trying to use the RXTX library for blocking serial communication on Windows (XP and 7). I have tested the connection with Hyperterminal in both ends, and it works flawlessly.

我使用以下代码建立连接:(为清楚起见，省略了异常处理和防御性检查）

I set up the connection with the following code: (exception handling and defensive checks omitted for clarity)

private InputStream inStream;
private OutputStream outStream;
private BufferedReader inReader;
private PrintWriter outWriter;
private SerialPort serialPort;
private final String serialPortName;

public StreamComSerial(String serialPortName) {
this.serialPortName = serialPortName;
CommPortIdentifier portIdentifier;
portIdentifier = CommPortIdentifier.getPortIdentifier(serialPortName);
CommPort commPort = null;
commPort = portIdentifier.open(this.getClass().getName(),500);
serialPort = (SerialPort) commPort;    serialPort.setSerialPortParams(4800,SerialPort.DATABITS_8,SerialPort.STOPBITS_1,SerialPort.PARITY_NONE);
inStream = serialPort.getInputStream();
outStream = serialPort.getOutputStream();
inReader = new BufferedReader(new InputStreamReader(inStream, Settings.getCharset()));
outWriter = new PrintWriter(new OutputStreamWriter(outStream, Settings.getCharset()));

当我使用

outWriter.println("test message");
flush();

邮件在另一端收到罚款，但是打电话

the message is recieved fine on the other end, but calling

inReader.readLine()

imidiately返回java.io.IOException：底层输入流返回零字节。

imidiately returns "java.io.IOException: Underlying input stream returned zero bytes".

然后我决定尝试实现自己的阻塞读取逻辑并写下：

I then decided to try and implement my own blocking read logic and wrote this:

public String readLine() throws IOException {
    String line = new String();
    byte[] nextByte = {-1};
    while (true) {
        nextByte[0] = (byte)inStream.read();
        logger.debug("int read: " + nextByte[0]);
        if (nextByte[0] == (byte)-1) {
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            continue;
        }
        logger.debug("byte read: " + nextByte[0]);

        line = line + new String(nextByte);
        if (nextByte[0] == (byte)13) {  // 13 is carriage return in ASCII
            return line;
        }
    }
}

但这段代码是无限循环和nextByte [0] =（byte）inStream.read（）;无论通过串行连接发送什么，都会分配-1。另外，另一端非常糟糕，只允许我每1-3秒发送一个角色。如果我尝试在短时间内发送许多字符，我会挂起很长时间。

But this code goes in an infinite loop and "nextByte[0] = (byte)inStream.read();" assigns -1 no matter what is sent over the serial connection. In addition, the other end stutters quite badly and only lets me send a character every 1-3 sec. and hangs for a long time if I try to send many characters in a short burst.

任何帮助非常感谢。

* edit - 使用inStream.read（nextByte）而不是nextByte [0] =（byte）inStream.read（）;不会写入nextByte变量，无论我通过串行连接发送给它。

*edit - using inStream.read(nextByte) instead of "nextByte[0] = (byte)inStream.read();" does not write to the nextByte variable, no matter what I send to it through the serial connection.

* edit2 - 因为我的代码与SUN javax.comm lib完美配合和我从朋友那里得到的win32com.dll，我已经停止尝试使其与RXTX一起使用。我对解锁通信不感兴趣，这似乎是其他人可以使RXTX工作的唯一方式。

*edit2 - as my code works flawlessly with the SUN javax.comm lib and a win32com.dll I got from a friend, I have ceased trying to make it work with RXTX. I am not interested in unblocking communication, which seems to be the only way other people can make RXTX work.

RXTX

RXTX串行连接 - 阻塞read（）的问题

问题描述

推荐答案