Java Runtime.getRuntime(): getting output from executing a command line program

Question

I\'m using the runtime to run command prompt commands from my Java program. However, I\'m not aware of how I can get the output the command returns.

Here is my code:

Answer 1

@Senthil and @Arend answer (https://stackoverflow.com/a/5711150/2268559) mentioned ProcessBuilder. Here is the example using ProcessBuilder with specifying environment variables and working folder for the command:

    ProcessBuilder pb = new ProcessBuilder("ls", "-a", "-l");

    Map env = pb.environment();
    // If you want clean environment, call env.clear() first
    //env.clear();
    env.put("VAR1", "myValue");
    env.remove("OTHERVAR");
    env.put("VAR2", env.get("VAR1") + "suffix");

    File workingFolder = new File("/home/user");
    pb.directory(workingFolder);

    Process proc = pb.start();

    BufferedReader stdInput = new BufferedReader(new InputStreamReader(proc.getInputStream()));

    BufferedReader stdError = new BufferedReader(new InputStreamReader(proc.getErrorStream()));

    // Read the output from the command:
    System.out.println("Here is the standard output of the command:\n");
    String s = null;
    while ((s = stdInput.readLine()) != null)
        System.out.println(s);

    // Read any errors from the attempted command:
    System.out.println("Here is the standard error of the command (if any):\n");
    while ((s = stdError.readLine()) != null)
        System.out.println(s);