在java中创建随机数

Question

我需要编写一个代码，为用户提供一个方程式，如果用户解决它，将会给出促销代码。

1，我只需要将随机数从1到9。

2，No＆＃34;随机＆＃34; JOptionpane中显示的数字：（！

3，我还需要一个包含多个数字（4位数字好）的随机数的促销代码。

提前致谢！

public class ZooMapFragment extends SupportMapFragment implements OnMapReadyCallback {

public static ZooMapFragment getInstance(){
    ZooMapFragment fragment = new ZooMapFragment();

    return fragment;
}

@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);

    CameraPosition position = CameraPosition.builder()
            .target(new LatLng(39.7494, -104.9498))
            .zoom(16f)
            .bearing(0.0f)
            .tilt(0.0f)
            .build();

    getMapAsync().animateCamera(CameraUpdateFactory.newCameraPosition( position ), null);
    getMapAsync().setMapType(GoogleMap.MAP_TYPE_HYBRID);
    getMapAsync().setTrafficEnabled( true );

    getMapAsync().getUiSettings().setZoomControlsEnabled( true );

    MarkerOptions options = new MarkerOptions().position( new LatLng( 39.7500, -104.9500 ) );
    options.title( "Zoo" );
    options.icon(BitmapDescriptorFactory.defaultMarker( BitmapDescriptorFactory.HUE_BLUE ) );
    getMapAsync().addMarker( options );

    getMapAsync().setOnMarkerClickListener( new GoogleMap.OnMarkerClickListener() {
        @Override
        public boolean onMarkerClick(Marker marker) {
            marker.showInfoWindow();
            return true;
        }
    });

    RestAdapter adapter = new RestAdapter.Builder()
            .setEndpoint(getString(R.string.pins_feed))
            .build();

    PinsApiInterface pinsApiInterface = adapter.create(PinsApiInterface.class);

    pinsApiInterface.getStreams(new Callback<List<Pin>>() {
        @Override
        public void success(List<Pin> pins, Response response) {
            for(Pin pin: pins){
                Log.e("Zoo", pin.getName());
            }
        }

        @Override
        public void failure(RetrofitError error) {

        }
    });
}


@Override
public void onMapReady(GoogleMap googleMap) {
    // Add a marker in Denver, Zoo
    // and move the map's camera to the same location.
    LatLng denverZoo = new LatLng(39.7500, -104.9500);
    googleMap.addMarker(new MarkerOptions().position(denverZoo)
            .title("Marker in Denver Zoo"));
    googleMap.moveCamera(CameraUpdateFactory.newLatLng(denverZoo));

}
}