使用Javax comm包读取ASCII数据

Question

我有一个设备将一些数据发送到COM端口，字节流是一个人类可读的ASCII字符流。我试着从端口读取器读取数据流，我可以很容易地读取，比如

Param   Flags   Value   Unit    [min-max]

WBC E 0.00 10^9/l[4.00-10.00]LYM 0.00 10^9/l[1.30-4.00]

但当我试图以字节形式从java程序中读取并转换为ASCII时，它仍然显示为行话。例如。���v�

我更改了数组大小，并尝试了各种选项将数组转换为ASCII。

排成一排就像

4C 4C 59 20 41 55 54 4F 4D 41 54 45 44 20 48 45全自动

非常感谢阅读正确格式的指导。

代码为

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;
    String line = "";
    BufferedReader portReader;
    public static void main(String[] args) {
        boolean portFound = false;
        String defaultPort = "COM6";
        if (args.length > 0) {
            defaultPort = args[0];
        }
        portList = CommPortIdentifier.getPortIdentifiers();
        while (portList.hasMoreElements()) {
            portId = (CommPortIdentifier) portList.nextElement();
            if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
                if (portId.getName().equals(defaultPort)) {
                    System.out.println("Found port: " + defaultPort);
                    portFound = true;
                    SimpleRead reader = new SimpleRead();
                }
            }
        }
        if (!portFound) {
            System.out.println("port " + defaultPort + " not found.");
        }
    }
    public SimpleRead() {
        try {
            serialPort = (SerialPort) portId.open("SimpleReadApp", 2000);
        } catch (PortInUseException e) {
            e.printStackTrace();
        }
        try {
            inputStream = serialPort.getInputStream();
        } catch (Exception e) {
            e.printStackTrace();
        }
        try {
            serialPort.addEventListener(this);
        } catch (TooManyListenersException e) {
            e.printStackTrace();
        }
        serialPort.notifyOnDataAvailable(true);
        try {
            serialPort.setSerialPortParams(9600, SerialPort.DATABITS_8,
                    SerialPort.STOPBITS_1,
                    SerialPort.PARITY_NONE);
        } catch (UnsupportedCommOperationException e) {
            e.printStackTrace();
        }
        readThread = new Thread(this);
        readThread.start();
    }
    public void run() {
        try {
            Thread.sleep(10);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
    public void serialEvent(SerialPortEvent event) {
        switch (event.getEventType()) {
            case SerialPortEvent.BI:
                System.out.println("BI");
            case SerialPortEvent.OE:
                System.out.println("OE");
            case SerialPortEvent.FE:
                System.out.println("FE");
            case SerialPortEvent.PE:
                System.out.println("PE");
            case SerialPortEvent.CD:
                System.out.println("CD");
            case SerialPortEvent.CTS:
                System.out.println("CTS");
            case SerialPortEvent.DSR:
                System.out.println("DSR");
            case SerialPortEvent.RI:
                System.out.println("RI");
            case SerialPortEvent.OUTPUT_BUFFER_EMPTY:
                System.out.println("OUTPUT_BUFFER_EMPTY");
                break;
            case SerialPortEvent.DATA_AVAILABLE:
                System.out.println("DATA_AVAILABLE");
                byte[] readBuffer = new byte[20];
                try {
                    while (inputStream.available() > 0) {
                        int numBytes = inputStream.read(readBuffer);
                        System.out.print("The Read Bytes from SerialPort are");
                        System.out.write(readBuffer);
                        System.out.println();
                    }
                    System.out.print(new String(readBuffer));
                } catch (IOException e) {
                    e.printStackTrace();
                }
                break;
        }
    }
}

Answer 1

在输出中，您没有指定要使用的字符集。由于您是通过串行端口接收的，我认为使用的字符集是US_ASCII或UTF_8。

要强制从t byte[]到字符串的转换使用特定的字符集，您必须指定它。

您的代码示例如下：

System.out.print(new String(readBuffer, StandardCharsets.UTF_8));

Java中的StandardCharset列表可以在这里找到