Execute linux command as superuser by default [closed]
Runtime.getRuntime().exec("su")

public void runCommandsAsRoot(String[] cmds) throws IOException {
    Process proc = Runtime.getRuntime().exec("su");

    DataOutputStream oStream = new DataOutputStream(proc.getOutputStream());

    for (String cmd : cmds) {
        oStream.writeBytes(cmd + "n");
    }

    oStream.writeBytes("exitn");
    oStream.flush();
}

String[] commands = { "fistCommand", "secondCommand" };
runCommandsAsRoot(commands);