Ask for Exit on Back Key Pressed

backkeyClose

@Override
    public void onBackPressed() {
        new AlertDialog.Builder(this).setIcon(R.drawable.ic_alert).setTitle("Exit")
                .setMessage("Are you sure you want to exit?")
                .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        finish();
                        System.exit(0);
                    }
                }).setNegativeButton("No", null).show();
    }