Fix a compatible bug for Gson 2.11.0+ (#1157)

Signed-off-by: yhmo <yihua.mo@zilliz.com>

examples/main/java/io/milvus/v2/HybridSearchExample.java

@@ -38,7 +38,7 @@ import io.milvus.v2.service.vector.request.data.BaseVector;
 import io.milvus.v2.service.vector.request.data.BinaryVec;
 import io.milvus.v2.service.vector.request.data.FloatVec;
 import io.milvus.v2.service.vector.request.data.SparseFloatVec;
-import io.milvus.v2.service.vector.request.ranker.RRFRanker;
+import io.milvus.v2.service.vector.request.ranker.WeightedRanker;
 import io.milvus.v2.service.vector.response.QueryResp;
 import io.milvus.v2.service.vector.response.SearchResp;
 
@@ -213,7 +213,7 @@ public class HybridSearchExample {
         HybridSearchReq hybridSearchReq = HybridSearchReq.builder()
                 .collectionName(COLLECTION_NAME)
                 .searchRequests(searchRequests)
-                .ranker(new RRFRanker(2))
+                .ranker(new WeightedRanker(Arrays.asList(0.2f, 0.5f, 0.6f)))
                 .topK(5)
                 .consistencyLevel(ConsistencyLevel.BOUNDED)
                 .build();

src/main/java/io/milvus/common/utils/JsonUtils.java

@@ -67,6 +67,6 @@ public class JsonUtils {
     }
 
     public static <T> JsonElement toJsonTree(T obj) {
-        return GSON_INSTANCE.toJsonTree(obj, new TypeToken<T>() {}.getType());
+        return GSON_INSTANCE.toJsonTree(obj);
     }
 }