I did it long ago: I spawn a small C++ program to do the job.
More secure than JNI: crashes don't touch the JAVA program.

Just to give you an idea of the program:

/******************************************************************************/
/*            CVmain()                                                              */
/* Decodes the command line and provides response for simple cases.           */
/* All responses start with a single line containing "OK" or "ERR",           */
/* optionally followed by output (refer to the "Ok" and "Err" macro's.        */
/******************************************************************************/
int CVmain(int argc, char* argv[], char* envp[])
{
            Sy_MODULE("CVmain()")
            CString s;
                  void ejectMedia(CString);

      if(argc == 1)
      {
            Ok;                                                // No arguments: sanity check.
      }
      else
      {
      CString command = argv[1];

            if(!command.CompareNoCase("version")) // Version
            {
            CString version = _sqr_0ID + 21;// Skip SCCS text.
            int index = version.Find("Main.cpp"); // Find filename.

                  Ok;
                  if(index > 0)                        // Extract program and version only.
                  {
                        version = version.Left(index) + version.Mid(index + 8);
                  }
                  printf("%s\n", version);
            }

            else if(!command.CompareNoCase("getenv")) // Getenv
            {
                  Ok;
                  for(char** v = envp;  *v;  ++v)
                  {
                        printf("%s\n", *v);
                  }
            }

            else if(!command.CompareNoCase("ejectMedia")) // EjectMedia
            {
                  if(argc < 3)
                  {
                        Err;
                        printf("NO TARGET ARGUMENT\n");
                  }
                  else
                  {
                        ejectMedia(argv[2]);
                  }
            }

            else if(!command.CompareNoCase("driveType")) // DriveType
            {
                  if(argc < 3)
                  {
                        Err;
                        printf("NO TARGET ARGUMENT\n");
                  }
                  else
                  {
                        s = driveType(argv[2][0]);      // Drive letter.
                        if(s == "?")
                        {
                              Err;
                        }
                        else
                        {
                              Ok;
                              printf("%s\n", s);
                        }
                  }
            }

            else if(!command.CompareNoCase("volumeList"))      // List all drives.
            {
                  volumeList();
....................
The output is captured by the JAVA program.
;JOOP!