Remove optional to get features (#177)

Optional is not required since api returns list instead of object.

Signed-off-by: Vijayan Balasubramanian <balasvij@amazon.com>

Author: VijayanB

src/main/java/org/opensearch/geospatial/GeospatialParser.java

@@ -12,7 +12,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
-import java.util.Optional;
 
 import org.opensearch.common.bytes.BytesReference;
 import org.opensearch.common.xcontent.XContentHelper;
@@ -77,18 +76,18 @@ public static Map<String, Object> convertToMap(BytesReference content) {
      * getFeatures will return features from given map input. This function abstracts the logic to parse given input and returns
      * list of Features if exists in Map format.
      * @param geoJSON given input which may contain GeoJSON Object
-     * @return Returns an Optional with the List of Features as map if input is GeoJSON,
-     * else, returns an empty Optional instance.
+     * @return Returns List of Features as map if input is GeoJSON,
+     * else, returns an empty list.
      */
-    public static Optional<List<Map<String, Object>>> getFeatures(final Map<String, Object> geoJSON) {
+    public static List<Map<String, Object>> getFeatures(final Map<String, Object> geoJSON) {
         final String type = extractValueAsString(geoJSON, TYPE_KEY);
         Objects.requireNonNull(type, TYPE_KEY + " cannot be null");
         if (Feature.TYPE.equalsIgnoreCase(type)) {
-            return Optional.of(List.of(geoJSON));
+            return List.of(geoJSON);
         }
         if (FeatureCollection.TYPE.equalsIgnoreCase(type)) {
-            return Optional.of(Collections.unmodifiableList(FeatureCollection.create(geoJSON).getFeatures()));
+            return Collections.unmodifiableList(FeatureCollection.create(geoJSON).getFeatures());
         }
-        return Optional.empty();
+        return List.of();
     }
 }

src/main/java/org/opensearch/geospatial/action/upload/geojson/ContentBuilder.java

@@ -45,8 +45,6 @@ private Optional<BulkRequestBuilder> prepareContentRequest(UploadGeoJSONRequestC
             .stream()
             .map(GeospatialParser::toStringObjectMap)
             .map(GeospatialParser::getFeatures)
-            .filter(Optional::isPresent)
-            .map(Optional::get)
             .flatMap(List::stream)
             .map(this::createIndexRequestBuilder)
             .map(indexRequestBuilder -> indexRequestBuilder.setIndex(content.getIndexName()))

src/test/java/org/opensearch/geospatial/GeospatialParserTests.java

@@ -9,7 +9,6 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Optional;
 
 import org.json.JSONArray;
 import org.json.JSONObject;
@@ -77,10 +76,10 @@ public void testConvertToMap() {
 
     public void testGetFeaturesWithGeoJSONFeature() {
         Map<String, Object> geoJSON = GeospatialObjectBuilder.randomGeoJSONFeature(new JSONObject()).toMap();
-        Optional<List<Map<String, Object>>> features = GeospatialParser.getFeatures(geoJSON);
-        assertTrue(features.isPresent());
-        assertEquals(1, features.get().size());
-        assertEquals(features.get().get(0), geoJSON);
+        List<Map<String, Object>> features = GeospatialParser.getFeatures(geoJSON);
+        assertFalse(features.isEmpty());
+        assertEquals(1, features.size());
+        assertEquals(features.get(0), geoJSON);
     }
 
     public void testGetFeaturesWithGeoJSONFeatureCollection() {
@@ -90,16 +89,16 @@ public void testGetFeaturesWithGeoJSONFeatureCollection() {
         features.put(GeospatialObjectBuilder.randomGeoJSONFeature(new JSONObject()));
 
         JSONObject collection = GeospatialObjectBuilder.buildGeoJSONFeatureCollection(features);
-        Optional<List<Map<String, Object>>> featureList = GeospatialParser.getFeatures(collection.toMap());
-        assertTrue(featureList.isPresent());
-        assertEquals(featureList.get().size(), features.length());
+        List<Map<String, Object>> featureList = GeospatialParser.getFeatures(collection.toMap());
+        assertFalse(featureList.isEmpty());
+        assertEquals(featureList.size(), features.length());
     }
 
     public void testGetFeaturesWithUnSupportedType() {
         Map<String, Object> geoJSON = new HashMap<>();
         geoJSON.put(Feature.TYPE_KEY, "invalid-type");
-        Optional<List<Map<String, Object>>> features = GeospatialParser.getFeatures(geoJSON);
-        assertFalse(features.isPresent());
+        List<Map<String, Object>> features = GeospatialParser.getFeatures(geoJSON);
+        assertTrue(features.isEmpty());
     }
 
 }