Java I/O How to - Redirect input and output from operating systems processes

Question

We would like to know how to redirect input and output from operating systems processes.

Answer

/* w w  w . ja v  a 2  s  .  c  om*/
import java.io.File;

public class Main {

  public static void main(String[] args) throws Exception {
    File commands = new File("C:/Projects/ProcessCommands.txt");
    File output = new File("C:/Projects/ProcessLog.txt");
    File errors = new File("C:/Projects/ErrorLog.txt");

    ProcessBuilder pb = new ProcessBuilder("cmd");
    System.out.println(pb.redirectInput().toString());
    System.out.println(pb.redirectOutput().toString());
    System.out.println(pb.redirectError().toString());

    pb.redirectInput(commands);
    pb.redirectError(errors);
    pb.redirectOutput(output);
    System.out.println(pb.redirectInput().toString());
    System.out.println(pb.redirectOutput().toString());
    System.out.println(pb.redirectError().toString());

    pb.start();
  }
}

The code above generates the following result.