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

Also we can use streams for obtain command output:

public static void main(String[] args) throws IOException {

        Runtime runtime = Runtime.getRuntime();
        String[] commands  = {"free", "-h"};
        Process process = runtime.exec(commands);

        BufferedReader lineReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
        lineReader.lines().forEach(System.out::println);

        BufferedReader errorReader = new BufferedReader(new InputStreamReader(process.getErrorStream()));
        errorReader.lines().forEach(System.out::println);
    }