1 files changed, 10 insertions, 17 deletions

diff --git a/platform/android/src/geojson/polygon.cpp b/platform/android/src/geojson/polygon.cpp
index 96058b63b3..4437d134a8 100644
--- a/platform/android/src/geojson/polygon.cpp
+++ b/platform/android/src/geojson/polygon.cpp
@@ -8,29 +8,24 @@ namespace mbgl {
 namespace android {
 namespace geojson {
 
-jni::Object<Polygon> Polygon::New(jni::JNIEnv& env, const mbgl::Polygon<double>& polygon) {
-    auto jList = asPointsListsList(env, polygon);
-
+jni::Local<jni::Object<Polygon>> Polygon::New(jni::JNIEnv& env, const mbgl::Polygon<double>& polygon) {
+    static auto& javaClass = jni::Class<Polygon>::Singleton(env);
     static auto method = javaClass.GetStaticMethod<jni::Object<Polygon> (jni::Object<java::util::List>)>(env, "fromLngLats");
-    auto jPolygon = javaClass.Call(env, method, jList);
 
-    jni::DeleteLocalRef(env, jList);
-    return jPolygon;
+    return javaClass.Call(env, method, asPointsListsList(env, polygon));
 }
 
-mapbox::geojson::polygon Polygon::convert(jni::JNIEnv &env, jni::Object<Polygon> jPolygon) {
+mapbox::geojson::polygon Polygon::convert(jni::JNIEnv &env, const jni::Object<Polygon>& jPolygon) {
     mapbox::geojson::polygon polygon;
 
     if (jPolygon) {
-        auto jPositionListsList = Polygon::coordinates(env, jPolygon);
-        polygon = Polygon::convert(env, jPositionListsList);
-        jni::DeleteLocalRef(env, jPositionListsList);
+        polygon = Polygon::convert(env, Polygon::coordinates(env, jPolygon));
     }
 
     return polygon;
 }
 
-mapbox::geojson::polygon Polygon::convert(jni::JNIEnv &env, jni::Object<java::util::List/*<java::util::List<Point>>*/> jPointListsList) {
+mapbox::geojson::polygon Polygon::convert(jni::JNIEnv &env, const jni::Object<java::util::List/*<java::util::List<Point>>*/>& jPointListsList) {
     mapbox::geojson::polygon polygon;
 
     if (jPointListsList) {
@@ -45,18 +40,16 @@ mapbox::geojson::polygon Polygon::convert(jni::JNIEnv &env, jni::Object<java::ut
 }
 
 
-jni::Object<java::util::List> Polygon::coordinates(jni::JNIEnv &env, jni::Object<Polygon> jPolygon) {
-    static auto method = Polygon::javaClass.GetMethod<jni::Object<java::util::List> ()>(env, "coordinates");
+jni::Local<jni::Object<java::util::List>> Polygon::coordinates(jni::JNIEnv &env, const jni::Object<Polygon>& jPolygon) {
+    static auto& javaClass = jni::Class<Polygon>::Singleton(env);
+    static auto method = javaClass.GetMethod<jni::Object<java::util::List> ()>(env, "coordinates");
     return jPolygon.Call(env, method);
 }
 
 void Polygon::registerNative(jni::JNIEnv &env) {
-    // Lookup the class
-    javaClass = *jni::Class<Polygon>::Find(env).NewGlobalRef(env).release();
+    jni::Class<Polygon>::Singleton(env);
 }
 
-jni::Class<Polygon> Polygon::javaClass;
-
 } // namespace geojson
 } // namespace android
 } // namespace mbgl
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