Replace Gson.deepClone workaround

jest-common/src/main/java/io/searchbox/client/JestResult.java

@@ -2,6 +2,7 @@
 
 import com.google.gson.*;
 import io.searchbox.annotations.JestId;
+import io.searchbox.cloning.CloneUtils;
 import org.apache.commons.lang3.StringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -200,7 +201,7 @@ protected List<JsonElement> extractSource(boolean addEsMetadataIdField) {
                                 JsonObject currentObj = element.getAsJsonObject();
                                 JsonObject source = currentObj.getAsJsonObject(sourceKey);
                                 if (source != null) {
-                                    JsonObject copy = GsonUtils.deepCopy(source);
+                                    JsonObject copy = (JsonObject)CloneUtils.deepClone(source);
                                     if (addEsMetadataIdField) {
                                         copy.add(ES_METADATA_ID, currentObj.get("_id"));
                                     }
@@ -210,7 +211,7 @@ protected List<JsonElement> extractSource(boolean addEsMetadataIdField) {
                         }
                     }
                 } else if (obj != null) {
-                    JsonElement copy = GsonUtils.deepCopy(obj);
+                    JsonElement copy = (JsonElement)CloneUtils.deepClone(obj);
                     JsonElement objId = jsonObject.get("_id");
                     if ((objId != null) && copy.isJsonObject() && addEsMetadataIdField) {
                         copy.getAsJsonObject().add(ES_METADATA_ID, objId);

jest-common/src/main/java/io/searchbox/cloning/CloneUtils.java

@@ -0,0 +1,44 @@
+package io.searchbox.cloning;
+
+import com.google.gson.*;
+
+import java.util.Map;
+
+/**
+ * This class is just a workaround for the non-public deepCopy methods in Gson.
+ */
+public class CloneUtils {
+    public static JsonElement deepClone(JsonElement jsonElement) {
+        if (jsonElement instanceof JsonObject) {
+            return deepCloneObject(jsonElement);
+        } else if (jsonElement instanceof JsonArray) {
+            return deepCloneArray(jsonElement);
+        } else if (jsonElement instanceof JsonPrimitive) {
+            return jsonElement;
+        }
+
+        return JsonNull.INSTANCE;
+    }
+
+    private static JsonElement deepCloneObject(JsonElement jsonElement) {
+        JsonObject jsonObject = (JsonObject) jsonElement;
+        JsonObject result = new JsonObject();
+
+        for (Map.Entry<String, JsonElement> entry : jsonObject.entrySet()) {
+            result.add(entry.getKey(), deepClone(entry.getValue()));
+        }
+
+        return result;
+    }
+
+    private static JsonElement deepCloneArray(JsonElement jsonElement) {
+        JsonArray jsonArray = (JsonArray) jsonElement;
+        JsonArray result = new JsonArray();
+
+        for (JsonElement element : jsonArray) {
+            result.add(deepClone(element));
+        }
+
+        return result;
+    }
+}

jest-common/src/main/java/io/searchbox/core/SearchResult.java

@@ -4,6 +4,7 @@
 import io.searchbox.client.JestResult;
 import io.searchbox.core.search.aggregation.MetricAggregation;
 import io.searchbox.core.search.aggregation.RootAggregation;
+import io.searchbox.cloning.CloneUtils;
 import org.apache.commons.lang3.builder.EqualsBuilder;
 import org.apache.commons.lang3.builder.HashCodeBuilder;
 
@@ -111,7 +112,7 @@ protected <T, K> Hit<T, K> extractHit(Class<T> sourceType, Class<K> explanationT
                 List<String> sort = extractSort(hitObject.getAsJsonArray(SORT_KEY));
 
                 if (id != null) {
-                    source = GsonUtils.deepCopy(source);
+                    source = (JsonObject)CloneUtils.deepClone(source);
                     source.add(ES_METADATA_ID, id);
                 }
                 hit = new Hit<T, K>(