private void rebootSystem(){ 
    PowerManager pManager=(PowerManager) getSystemService(Context.POWER_SERVICE); 
    pManager.reboot(""); 
} 

private void rebootSystem(){
 Intent reboot = new Intent(Intent.ACTION_REBOOT);
 reboot.putExtra("nowait", 1);
 reboot.putExtra("interval", 1);
 reboot.putExtra("window", 0);
 sendBroadcast(reboot);
}