Draw Android Map Poly Line

Manifest:

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

<activity
    android:name=".activity.MapsActivity"
    android:label="@string/title_activity_maps" />

<meta-data
    android:name="com.google.android.geo.API_KEY"
    android:value="@string/google_maps_key" />

Java:

public class MapsActivity extends BaseActivity {

    private GoogleMap googleMap;

    private double fromLatitude = 1.306444;
    private double fromLongitude = 103.851109;

    private double toLatitude = 1.329356;
    private double toLongitude = 103.877889;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);
        // Obtain the SupportMapFragment and get notified when the map is ready to be used.
        googleMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();
        googleMap.getUiSettings().setMapToolbarEnabled(false);

        List<LatLng> points = Arrays.asList(new LatLng(fromLatitude, fromLongitude),
                new LatLng(toLatitude, toLongitude));

        PolygonOptions options = new PolygonOptions();
        options.addAll(points);
        options.fillColor(getResources().getColor(R.color.app_theme_color));
        options.strokeColor(getResources().getColor(R.color.app_theme_color));
        googleMap.addPolygon(options);

        googleMap.addMarker(new MarkerOptions()
                .position(new LatLng(fromLatitude, fromLongitude))
                .title("You Are here")
                .snippet("Order placed"));
        googleMap.addMarker(new MarkerOptions()
                .position(new LatLng(toLatitude, toLongitude))
                .title("Destination Position")
                .snippet("Order placed"));

        midPoint(fromLatitude, fromLongitude, toLatitude, toLongitude);
    }

    public void midPoint(double lat1, double lon1, double lat2, double lon2) {

        double dLon = Math.toRadians(lon2 - lon1);

        //convert to radians
        lat1 = Math.toRadians(lat1);
        lat2 = Math.toRadians(lat2);
        lon1 = Math.toRadians(lon1);

        double Bx = Math.cos(lat2) * Math.cos(dLon);
        double By = Math.cos(lat2) * Math.sin(dLon);
        double lat3 = Math.atan2(Math.sin(lat1) + Math.sin(lat2), Math.sqrt((Math.cos(lat1) + Bx) * (Math.cos(lat1) + Bx) + By * By));
        double lon3 = lon1 + Math.atan2(By, Math.cos(lat1) + Bx);

        //print out in degrees
        System.out.println(Math.toDegrees(lat3) + " " + Math.toDegrees(lon3));

        CameraUpdate center = CameraUpdateFactory.newLatLng(new LatLng(Math.toDegrees(lat3), Math.toDegrees(lon3)));
        CameraUpdate zoom = CameraUpdateFactory.zoomTo(14);
        googleMap.moveCamera(center);
        googleMap.animateCamera(zoom);
    }

}

Xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:elevation="7dp"
    android:fitsSystemWindows="false"
    tools:context=".activity.MapsActivity">

    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">/>

        <fragment
            android:id="@+id/map"
            android:name="com.google.android.gms.maps.SupportMapFragment"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />

        <RelativeLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:background="@drawable/editext_border_login"
            android:layout_margin="@dimen/margin10">

            <Button
                android:id="@+id/email_sign_in_button"
                style="?android:textAppearanceSmall"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_margin="@dimen/margin20"
                android:background="@drawable/login_btn_selector"
                android:text="@string/action_view_direction"
                android:textAllCaps="false"
                android:textColor="@color/white"
                android:textStyle="bold" />
        </RelativeLayout>
  </RelativeLayout>
</RelativeLayout>

Images:

Screen Shot: