added loadJsonFromAsset() method

MapboxAndroidDemo/src/main/java/com/mapbox/mapboxandroiddemo/examples/styles/VariableLabelPlacementActivity.java

@@ -18,6 +18,7 @@
 import com.mapbox.mapboxsdk.style.layers.SymbolLayer;
 import com.mapbox.mapboxsdk.style.sources.GeoJsonSource;
 
+import java.io.IOException;
 import java.io.InputStream;
 import java.lang.ref.WeakReference;
 import java.util.Scanner;
@@ -66,7 +67,8 @@ protected void onCreate(Bundle savedInstanceState) {
       @Override
       public void onMapReady(@NonNull final MapboxMap mapboxMap) {
         mapboxMap.setStyle(new Style.Builder().fromUrl(Style.LIGHT)
-                .withSource(new GeoJsonSource(GEOJSON_SRC_ID,"asset://poi_places.geojson"))
+                .withSource(new GeoJsonSource(GEOJSON_SRC_ID,
+                    loadJsonFromAsset("poi_places.geojson")))
                 // Adds a SymbolLayer to display POI labels
                 .withLayer(new SymbolLayer(POI_LABELS_LAYER_ID, GEOJSON_SRC_ID)
                     .withProperties(
@@ -90,6 +92,22 @@ public void onStyleLoaded(@NonNull final Style style) {
     });
   }
 
+  private String loadJsonFromAsset(String filename) {
+    // Using this method to load in GeoJSON files from the assets folder.
+    try {
+      InputStream is = getAssets().open(filename);
+      int size = is.available();
+      byte[] buffer = new byte[size];
+      is.read(buffer);
+      is.close();
+      return new String(buffer, "UTF-8");
+
+    } catch (IOException ex) {
+      ex.printStackTrace();
+      return null;
+    }
+  }
+
   // Add the mapView lifecycle to the activity's lifecycle methods
   @Override
   public void onResume() {