java - 无法打开端口

我在运行时调用库本机函数OpenSSPComPortUSB（）
  程序弹出窗口无法打开端口\。\ COM208。为什么回来
  \。\ COM208，因为我已经通过PortNumber = 7;下面是Java代码和我的
  目标是打开端口COM7以启动与Smart的串行通信
  希望者。

    //  AccessITLLib.java


   public class AccessITLLib
    {


       public static class SSP_COMMAND extends Structure
       {
           SSP_FULL_KEY Key;
            public NativeLong BaudRate;
            public byte PortNumber;
                    public NativeLong Timeout;
                    public byte SSPAddress;
                    public byte RetryLevel;
                    public byte EncryptionStatus;
                    public byte CommandDataLength;
                    public byte[] CommandData = new byte[255];
                    public byte ResponseStatus;
                    public byte ResponseDataLength;
                    public byte[] ResponseData = new byte[255];
                    public byte IgnoreError;


       }



       public interface ITLLib extends Library
       {
           ITLLib INSTANCE = (ITLLib) Native.loadLibrary("ITLSSPproc",
                   ITLLib.class);

           public int OpenSSPComPort(SSP_COMMAND p);
           public int OpenSSPComPortUSB(SSP_COMMAND p);
           public int CloseSSPComPort();
           public int CloseSSPComPortUSB();
       }

       public static void main(String[] args)
       {
          SSP_COMMAND commandStruct = new SSP_COMMAND();
          commandStruct.BaudRate = new NativeLong(9600);
          commandStruct.PortNumber =7;
          commandStruct.Timeout = 500;
          commandStruct.RetryLevel = 3;
          commandStruct.IgnoreError = 1;
          commandStruct.SSPAddress =16;



          ITLLib.INSTANCE.CloseSSPComPort();
          ITLLib.INSTANCE.CloseSSPComPortUSB();
          ITLLib.INSTANCE.OpenSSPComPort(commandStruct);
          ITLLib.INSTANCE.OpenSSPComPortUSB(commandStruct);



       }
    }


 here are the c structures
    typedef struct{
        SSP_FULL_KEY Key;
        unsigned long BaudRate;
        unsigned long Timeout;
        unsigned char PortNumber;
        unsigned char SSPAddress;
        unsigned char RetryLevel;
        unsigned char EncryptionStatus;
        unsigned char CommandDataLength;
        unsigned char CommandData[255];
        unsigned char ResponseStatus;
        unsigned char ResponseDataLength;
        unsigned char ResponseData[255];
        unsigned char IgnoreError;
    }SSP_COMMAND;



    typedef struct{
        unsigned long long FixedKey;
        unsigned long long EncryptKey;
    }SSP_FULL_KEY;

最佳答案

您的JNA结构定义与本机定义的布局不匹配。

JNA中的字段顺序必须与本机定义的字段顺序完全匹配（JNA的最新版本实际上要求您实现显式声明字段顺序的方法）。

您无意间交换了PortNumber和Timeout字段。

关于java - 无法打开端口，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/14723188/