如何正确地将byte []转换为String？

Question

我正在使用swingJava 构建一个接口,我构建了一个middleware不断读取串口并保存所需内容的接口String,这就是我在做这个的方式:

public class RFID {
  private static RFIDReader rReader;
  private static boolean state;

  public RFID(RFIDReader rReader) {
    this.rReader = rReader;
    this.state = true;
  }

  public void connect(String portName) throws Exception {
    CommPortIdentifier portIdentifier = CommPortIdentifier.getPortIdentifier(portName);
    if (portIdentifier.isCurrentlyOwned()) {
        System.out.println("Error: Port is currently in use");
    } else {
        CommPort commPort = portIdentifier.open(this.getClass().getName(), 2000);

        if (commPort instanceof SerialPort) {
            SerialPort serialPort = (SerialPort) commPort;
            serialPort.setSerialPortParams(9600, SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);

            InputStream in = serialPort.getInputStream();
            OutputStream out = serialPort.getOutputStream();

            (new Thread(new SerialReader(in))).start();
            //(new Thread(new SerialWriter(out))).start();

        } else {
            System.out.println("Error: Only serial ports are handled by this example.");
        }
    }
}

public static class SerialReader implements Runnable {

    InputStream in;

    public SerialReader(InputStream in) {
        this.in = in;
    }

    public void run() {
        byte[] buffer = new byte[1024];
        int len = -1;
        String code;
        try {
            while (state == true && (len = this.in.read(buffer)) > -1) {
                code = new String(buffer, 0, len);
                if (code.length() > 1)
                    rReader.setCode(code);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

public void finish(){
    state = false;
}

public static class SerialWriter implements Runnable {

    OutputStream out;

    public SerialWriter(OutputStream out) {
        this.out = out;
    }

    public void run() {
        try {
            int c = 0;
            while ((c = System.in.read()) > -1) {
                this.out.write(c);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

因此,当我尝试打印code正在存储的内容时,它显示如下:

AC000F9
3
BB

实际应该是这样的:

AC000F93BB

我在这做错了什么？这从转换byte[]到String是不正确的？

编辑: 我需要读一个总共10个字符的字符串.

Answer 1

不要InputStream用来读取 - 使用Reader一些描述.如果你需要从a开始InputStream,请将其包装成InputStreamReader.我会改变你的构造函数来接受一个,Reader但允许客户端传递他们想要的任何读者.这将使测试更容易(因为你可以使用a StringReader).

编辑:注意 - 如果您确实需要从二进制文件创建一个阅读器InputStream,请明确选择Charset(编码).所以使用InputStreamReader指定一个的构造函数重载.即使您想使用平台默认设置,我也会明确说明您正在做什么.

编辑:除了"字符串转换发生的地方"之外,还不清楚你期望读什么.您正在处理流式传输API - 决定在调用之前您真正想要读取setCode多少内容？这是一条整线吗？是一些固定数量的字符？它是特定分隔符之前的字符吗？

编辑:现在我们知道了一点,我建议你写一个这样的辅助方法:

// Assuming you now have a field of type Reader, called reader
private String readEntry() throws IOException {
    char[] buffer = new char[10];
    int index = 0;
    while (index < buffer.length) {
        int charsRead = reader.read(buffer, index, buffer.length - index);
        if (charsRead == -1) {
            throw new IOException("Couldn't read entry - end of data");
        }
        index += charsRead;
    }
    return new String(buffer);
}