[GEOS-8750] Improve GeoJSON output format with WFS3 suggested propert…

…ies, make the output format extensible

src/extension/app-schema/app-schema-test/src/test/java/org/geoserver/test/FeatureChainingWfsTest.java

@@ -1684,6 +1684,10 @@ private void testJsonRequest(String featureType, String expectResultPath) throws
         JSONObject resultJson = (JSONObject) result;
         // check the returned JSON againts the expected result
         JSONObject expectedJson = readJsonObject(expectResultPath);
+
+        // the timestamp attribute cannot be the same, remove it
+        resultJson.remove("timeStamp");
+
         assertThat(resultJson, is(expectedJson));
     }
 

src/extension/app-schema/app-schema-test/src/test/resources/test-data/FirstParentFeature.json

@@ -42,5 +42,6 @@
     }
   ],
   "totalFeatures": "unknown",
+  "numberReturned": 5,
   "type": "FeatureCollection"
 }

src/extension/app-schema/app-schema-test/src/test/resources/test-data/MappedFeature.json

@@ -453,5 +453,6 @@
     }
   ],
   "totalFeatures": "unknown",
+  "numberReturned": 4,
   "type": "FeatureCollection"
 }

src/extension/app-schema/app-schema-test/src/test/resources/test-data/MultipleCollections.json

@@ -646,5 +646,6 @@
     }
   ],
   "totalFeatures": "unknown",
+  "numberReturned": 7,
   "type": "FeatureCollection"
 }

src/extension/app-schema/app-schema-test/src/test/resources/test-data/Observation.json

@@ -753,5 +753,6 @@
     }
   ],
   "totalFeatures": "unknown",
+  "numberReturned": 4,
   "type": "FeatureCollection"
 }

src/extension/app-schema/app-schema-test/src/test/resources/test-data/ParentFeature.json

@@ -60,5 +60,6 @@
     }
   ],
   "totalFeatures": "unknown",
+  "numberReturned": 3,
   "type": "FeatureCollection"
 }

src/wfs/src/main/java/org/geoserver/wfs/WFSGetFeatureOutputFormat.java

@@ -188,7 +188,7 @@ protected boolean canHandleInternal(Operation operation) {
     /**
      * Calls through to {@link #write(FeatureCollectionResponse, OutputStream, Operation)}.
      */
-    public final void write(Object value, OutputStream output, Operation operation)
+    public void write(Object value, OutputStream output, Operation operation)
         throws IOException, ServiceException {
         //for WFS 2.0 we changed the input object type to be the request object adapter, but there
         // is other code (like WMS GetFeatureInfo) that passes in the old objects, so do a check 

src/wfs/src/main/java/org/geoserver/wfs/json/ComplexGeoJsonWriter.java

@@ -31,7 +31,7 @@
 /**
  * GeoJSON writer capable of handling complex features.
  */
-public final class ComplexGeoJsonWriter {
+class ComplexGeoJsonWriter {
 
     private final GeoJSONBuilder jsonWriter;
 
@@ -66,7 +66,7 @@ private void encodeFeatureCollection(FeatureIterator iterator) {
     /**
      * Encode a feature in GeoJSON.
      */
-    private void encodeFeature(Feature feature) {
+    protected void encodeFeature(Feature feature) {
         // start the feature JSON object
         jsonWriter.object();
         jsonWriter.key("type").value("Feature");