How can I run the C program which will interact with user

Question

hi, all
I wanna run a C program whose function is that just show a line of characters, waiting for user input and finally show what user has entered. The C can run correctly in command window. But when I use Runtime class, it can not run correctly. My question is that how I can emulate that C program just by invoking Java method. The code I have written below, thank.
      String command = "cmd /c a.exe";  // a.exe is that C program
      String s;
      try {
         Process process = Runtime.getRuntime().exec(command);
         InputStream input = process.getInputStream();
         BufferedReader bufferedReader =
            new BufferedReader(new InputStreamReader(input));
         while((s = bufferedReader.readLine()) != null)
              System.out.println(s);
      catch(IOException e) {
         System.err.println("IOException: " + e.getMessage());
      }

Answer 1

http://java.sun.com/j2se/1.5.0/docs/api/java/lang/Process.html#getOutputStream()