如何以编程方式关闭Android 4.0 rooted Device

Question

Please help me to find out solution for this, I Know there are so many questions and duplicates about this same but here i describe whole things which i tried.

I have one android device where its installed 4.0 version of android. I want to shutdown this device using my one demo application.

1) Demo application is signed by platform keys which are used in built in file system.
2) Device is already rooted as its development board and i have all permissions on this.

Application contains Following things

1) Application is system application
2) Application signed by platform keys which are used in built in file system.

For make automation easier, I did import the key/cert pair into my java keystore file, with the this keytool-importkeypair and use eclipse for signing.

Used command is mentioned below.

Commad : keytool-importkeypair -k ~/Desktop/myown.keystore -p android -pk8 platform.pk8 -cert platform.x509.pem -alias platform

I used following code for reboot but i never make success in this .I read So many questions and answers on stackoverflow but they all said you require

1) root access of device
2) signed apk with any one keys which are available on `build/target/product/security/`
3) Given Proper permission in AndroidManifest.xml file.

Am i right in alomg points?

Application code :

First Try

public static void shutdown2() {

Runtime runtime = Runtime.getRuntime();
Process proc = null;
OutputStreamWriter osw = null;

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

try { // Run Script

    proc = runtime.exec("/system/xbin/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();
}
if (proc.exitValue() != 0) {
}
 }

Second Try :

private void shutdown3() {
        try {

            String[] cmd = { "/system/bin/sh","su","reboot -p"};

            Process proc = Runtime.getRuntime().exec(cmd);
            proc.waitFor();
        } catch (Exception ex) {
            Log.i("TAG", "Could not reboot 3  ", ex);
        }
    }

3rd Try :

private void shutdown() {
        try {
            Process proc = Runtime.getRuntime().exec(
                    new String[] { "/system/bin/su", "-c",
                            "/system/bin/reboot -p" });
            proc.waitFor();
        } catch (Exception ex) {
            Log.i("TAG", "Could not reboot 1 ", ex);
        }
    }

In 3rd method I also tried with "/system/bin/su"

Answer 1

The below code worked for me

        Process process = Runtime.getRuntime()
                .exec(new String[]{ "su", "-c", "busybox poweroff -f"});
        process.waitFor();

Answer 2

A much better solution is to run:

su -c am start -a android.intent.action.ACTION_REQUEST_SHUTDOWN

You can use a Process for this.