Rob Rob - 2 months ago 35
Java Question

Runtime.exec() : Reboot in Android?

I'm looking for a solution which can be used to reboot a rooted device. I jknow that rebooting a device is very poor design for the user, as stated here, and it's not really for an application. The main purpose is to reboot the phone during my tests (I work on a video chat application, and sometimes I need to reboot when everything goes south)

I observed that rebooting a phone is far far quicker using reboot in a terminal (

adb shell
or ConnectBot for instance) than going through the usual of rebooting with the ACTION_REBOOT, that I can't use anyway.

For the moment, I'm able to get the superuser privileges, with

Process root = Runtime.getRuntime().exec("su");


But I can't do the actual reboot. I try on a G1 (HTC) and on a Galaxy S (Samsung) without any success. I located the reboot executable in
/system/bin/reboot


Here are some of my attempts :

Process reboot = Runtime.getRuntime().exec("/system/bin/reboot");
Process reboot = Runtime.getRuntime().exec("reboot");
Process reboot = Runtime.getRuntime().exec("su reboot");


I read this article about the pitfalls of Runtime.exec(), but I think I'm not in this case.

As using ConnectBot enable me to do such an action, I'm pretty sure it's possible. Please don't tell me to go and have a look to the ConnectBot code, it's a big and complicated project :)

Can you help me with this issue ?

Thanks.

Answer

reboot works fine in android. you are probably not doing runtime.exec() properly. you need to handle the

    public static void rebootSU() {
    Runtime runtime = Runtime.getRuntime();
    Process proc = null;
    OutputStreamWriter osw = null;
    StringBuilder sbstdOut = new StringBuilder();
    StringBuilder sbstdErr = new StringBuilder();

    String command="/system/bin/reboot";

    try { // Run Script

        proc = runtime.exec("su");
        osw = new OutputStreamWriter(proc.getOutputStream());
                            osw.write(command);
                osw.flush();
        osw.close();

    } catch (IOException ex) {
        ex.printStackTrace();
    } finally {
        if (osw != null) {
            try {
                osw.close();
            } catch (IOException e) {
                e.printStackTrace();                    
            }
        }
    }
    try {
        if (proc != null)
            proc.waitFor();
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
    sbstdOut.append(ReadBufferedReader(new InputStreamReader(proc
            .getInputStream())));
    sbstdErr.append(ReadBufferedReader(new InputStreamReader(proc
            .getErrorStream())));
    if (proc.exitValue() != 0) {
                }
        }