Redirecting Input/Output/Error Streams of a CMD.exe Process Completely with Java

My aim with this project was to have a remote command prompt feel with Java. Using TCP/IP sockets, I was aiming to run a command prompt process on one computer, and virtually transmit all control to the other s开发者_运维问答ide. I immediately stumbled over Runtime.getRuntime().exec() and Process objects, etc. I've solved my problem about halfway. With my remote command prompt, I can run a single command, gather the output, and send it back to the other side. The problem is, I can only seem to run one command per command prompt instance. This won't do (with situations where I need to change directory and THEN run a command, etc). I've stripped all socket/networking programming from this situation to show you (and to create an easier testing environment for me).

import java.io.*;


public class testingProgram {

 public static void main(String[] args) {

  Runtime rt = Runtime.getRuntime();
  StringBuilder inputMessage = new StringBuilder();
  String resultData;
  try {

   Process pr = rt.exec("cmd.exe /c net user");
   BufferedReader processInput = new BufferedReader(new InputStreamReader(pr.getInputStream()));
   BufferedReader errorProcessInput = new BufferedReader(new InputStreamReader(pr.getErrorStream()));
   PrintWriter processOut = new PrintWriter(pr.getOutputStream());
   while( (resultData = processInput.readLine()) != null ) {
      inputMessage.append(resultData + "\n");
   }
   resultData = inputMessage.toString();
   System.out.print(resultData);
  } catch(IOException e) {

  } //catch(InterruptedException e) {

  //}
 }

}

I have a lot more, but this is where my problem is. I can customize the command "net user" with a simple variable and message from the socketstream, so that's not my problem. My problem is that I need to create an ongoing command prompt instance, retaining all redirections of the input/output. Basically, I would like to be able to send another command AFTER "net user".

I have gathered and redirected the output stream. I want to be able to do something like:

processOut.write("net user");

I want to be able to use this, have the command prompt run the command, and retain the output (whether it be from the errorStream OR the inputStream).

I just need some more direction on how to go about doing this.

You should look into multi threading. What you basically want is a thread which keeps running and maintaining the rt.

Like this:

  String commandLine;
  while ((commandLine = System.in.readline()) != 'q') {
        Process pc = rt.exec(commandLine);
  }

For further reference on multithreading: http://download.oracle.com/javase/tutorial/essential/concurrency/procthread.html

You problem is that your program terminates after one call.

cheers

You're telling the command interpreter to terminate. Remove the /C after cmd.exe.

cmd /?
Starts a new instance of the Windows command interpreter

CMD [/A | /U] [/Q] [/D] [/E:ON | /E:OFF] [/F:ON | /F:OFF] [/V:ON | /V:OFF]
    [[/S] [/C | /K] string]

/C      Carries out the command specified by string and then terminates
/K      Carries out the command specified by string but remains
...