Further generics refinements

Based on Ignacio's work in 050df95,
we fix the BoundingBox generics, and also add a little more specificity
to the previous generics (replace <?> with <? extends SpatialPoint>).

server/src/main/java/org/elasticsearch/common/geo/BoundingBox.java

@@ -86,7 +86,7 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
 
     public abstract XContentBuilder toXContentFragment(XContentBuilder builder, boolean buildLatLonFields) throws IOException;
 
-    protected abstract static class BoundsParser<T extends SpatialPoint> {
+    protected abstract static class BoundsParser<T extends BoundingBox<? extends SpatialPoint>> {
         protected double top = Double.NaN;
         protected double bottom = Double.NaN;
         protected double left = Double.NaN;
@@ -98,7 +98,7 @@ protected BoundsParser(XContentParser parser) {
             this.parser = parser;
         }
 
-        public BoundingBox<T> parseBoundingBox() throws IOException, ElasticsearchParseException {
+        public T parseBoundingBox() throws IOException, ElasticsearchParseException {
             XContentParser.Token token = parser.currentToken();
             if (token != XContentParser.Token.START_OBJECT) {
                 throw new ElasticsearchParseException("failed to parse bounding box. Expected start object but found [{}]", token);
@@ -172,9 +172,9 @@ public BoundingBox<T> parseBoundingBox() throws IOException, ElasticsearchParseE
             return createWithBounds();
         }
 
-        protected abstract BoundingBox<T> createWithEnvelope();
+        protected abstract T createWithEnvelope();
 
-        protected abstract BoundingBox<T> createWithBounds();
+        protected abstract T createWithBounds();
 
         protected abstract SpatialPoint parsePointWith(XContentParser parser, GeoUtils.EffectivePoint effectivePoint) throws IOException;
     }

server/src/main/java/org/elasticsearch/common/geo/GeoBoundingBox.java

@@ -86,7 +86,7 @@ public void writeTo(StreamOutput out) throws IOException {
         out.writeGeoPoint(bottomRight);
     }
 
-    protected static class GeoBoundsParser extends BoundsParser<GeoPoint> {
+    protected static class GeoBoundsParser extends BoundsParser<GeoBoundingBox> {
         GeoBoundsParser(XContentParser parser) {
             super(parser);
         }
@@ -116,6 +116,6 @@ protected SpatialPoint parsePointWith(XContentParser parser, GeoUtils.EffectiveP
      */
     public static GeoBoundingBox parseBoundingBox(XContentParser parser) throws IOException, ElasticsearchParseException {
         GeoBoundsParser bounds = new GeoBoundsParser(parser);
-        return (GeoBoundingBox) bounds.parseBoundingBox();
+        return bounds.parseBoundingBox();
     }
 }

server/src/main/java/org/elasticsearch/index/fielddata/IndexPointFieldData.java

@@ -8,7 +8,9 @@
 
 package org.elasticsearch.index.fielddata;
 
+import org.elasticsearch.common.geo.SpatialPoint;
+
 /**
  * Specialization of {@link IndexFieldData} for geo points and points.
  */
-public interface IndexPointFieldData<T extends MultiPointValues<?>> extends IndexFieldData<LeafPointFieldData<T>> {}
+public interface IndexPointFieldData<T extends MultiPointValues<? extends SpatialPoint>> extends IndexFieldData<LeafPointFieldData<T>> {}

server/src/main/java/org/elasticsearch/index/fielddata/LeafPointFieldData.java

@@ -8,11 +8,12 @@
 package org.elasticsearch.index.fielddata;
 
 import org.apache.lucene.index.SortedNumericDocValues;
+import org.elasticsearch.common.geo.SpatialPoint;
 
 /**
  * {@link LeafFieldData} specialization for geo points and points.
  */
-public abstract class LeafPointFieldData<T extends MultiPointValues<?>> implements LeafFieldData {
+public abstract class LeafPointFieldData<T extends MultiPointValues<? extends SpatialPoint>> implements LeafFieldData {
 
     /**
      * Return geo-point or point values.

server/src/main/java/org/elasticsearch/index/fielddata/plain/AbstractPointIndexFieldData.java

@@ -8,6 +8,7 @@
 package org.elasticsearch.index.fielddata.plain;
 
 import org.apache.lucene.search.SortField;
+import org.elasticsearch.common.geo.SpatialPoint;
 import org.elasticsearch.common.util.BigArrays;
 import org.elasticsearch.core.Nullable;
 import org.elasticsearch.index.fielddata.IndexFieldData.XFieldComparatorSource.Nested;
@@ -20,7 +21,7 @@
 import org.elasticsearch.search.sort.BucketedSort;
 import org.elasticsearch.search.sort.SortOrder;
 
-abstract class AbstractPointIndexFieldData<T extends MultiPointValues<?>> implements IndexPointFieldData<T> {
+abstract class AbstractPointIndexFieldData<T extends MultiPointValues<? extends SpatialPoint>> implements IndexPointFieldData<T> {
 
     protected final String fieldName;
     protected final ValuesSourceType valuesSourceType;