Running Command Line in Java [duplicate]

Answer 1

Process p = Runtime.getRuntime().exec("java -jar map.jar time.rel test.txt debug");

Answer 2

Runtime.getRuntime().exec("java -jar map.jar time.rel test.txt debug");

Answer 3

To avoid the called process to be blocked if it outputs a lot of data on the standard output and/or error, you have to use the solution provided by Craigo. Note also that ProcessBuilder is better than Runtime.getRuntime().exec(). This is for a couple of reasons: it tokenizes better the arguments, and it also takes care of the error standard output (check also here).

ProcessBuilder builder = new ProcessBuilder("cmd", "arg1", ...);
builder.redirectErrorStream(true);
final Process process = builder.start();

// Watch the process
watch(process);

I use a new function "watch" to gather this data in a new thread. This thread will finish in the calling process when the called process ends.

private static void watch(final Process process) {
    new Thread() {
        public void run() {
            BufferedReader input = new BufferedReader(new InputStreamReader(process.getInputStream()));
            String line = null; 
            try {
                while ((line = input.readLine()) != null) {
                    System.out.println(line);
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }.start();
}

Answer 4

what about

public class CmdExec {

public static Scanner s = null;


public static void main(String[] args) throws InterruptedException, IOException {
    s = new Scanner(System.in);
    System.out.print("$ ");
    String cmd = s.nextLine();
    final Process p = Runtime.getRuntime().exec(cmd);

    new Thread(new Runnable() {
        public void run() {
            BufferedReader input = new BufferedReader(new InputStreamReader(p.getInputStream()));
            String line = null; 

            try {
                while ((line = input.readLine()) != null) {
                    System.out.println(line);
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }).start();

    p.waitFor();
     }

 }

Answer 5

import java.io.*;

Process p = Runtime.getRuntime().exec("java -jar map.jar time.rel test.txt debug");

Consider the following if you run into any further problems, but I'm guessing that the above will work for you:

Problems with Runtime.exec()

Answer 6

Runtime rt = Runtime.getRuntime();
Process pr = rt.exec("java -jar map.jar time.rel test.txt debug");

http://docs.oracle.com/javase/7/docs/api/java/lang/Runtime.html