log live variable parsing error when Gson parsing feature flags

Signed-off-by: wangjoshuah <wangjoshuah@gmail.com>

Author: wangjoshuah

core-api/src/main/java/com/optimizely/ab/config/parser/GsonHelpers.java

@@ -20,14 +20,18 @@
 import com.google.gson.JsonDeserializationContext;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
+import com.google.gson.JsonParseException;
 import com.google.gson.reflect.TypeToken;
+import com.optimizely.ab.bucketing.DecisionService;
 import com.optimizely.ab.config.Experiment;
 import com.optimizely.ab.config.Experiment.ExperimentStatus;
 import com.optimizely.ab.config.FeatureFlag;
 import com.optimizely.ab.config.LiveVariable;
 import com.optimizely.ab.config.LiveVariableUsageInstance;
 import com.optimizely.ab.config.TrafficAllocation;
 import com.optimizely.ab.config.Variation;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.lang.reflect.Type;
 import java.util.ArrayList;
@@ -38,6 +42,8 @@
 
 final class GsonHelpers {
 
+    private static final Logger logger = LoggerFactory.getLogger(DecisionService.class);
+
     private static List<Variation> parseVariations(JsonArray variationJson, JsonDeserializationContext context) {
         List<Variation> variations = new ArrayList<Variation>(variationJson.size());
         for (Object obj : variationJson) {
@@ -127,9 +133,17 @@ static FeatureFlag parseFeatureFlag(JsonObject featureFlagJson, JsonDeserializat
             experimentIds.add(experimentIdObj.getAsString());
         }
 
-        Type liveVariableType = new TypeToken<List<LiveVariable>>() {}.getType();
-        List<LiveVariable> liveVariables = context.deserialize(featureFlagJson.getAsJsonArray("variables"),
-                liveVariableType);
+        List<LiveVariable> liveVariables = new ArrayList<LiveVariable>();
+        try {
+            Type liveVariableType = new TypeToken<List<LiveVariable>>() {
+            }.getType();
+            liveVariables = context.deserialize(featureFlagJson.getAsJsonArray("variables"),
+                    liveVariableType);
+        }
+        catch (JsonParseException exception) {
+            logger.warn("Unable to parse variables for feature \"" + key
+                    + "\". JsonParseException: " + exception);
+        }
 
         return new FeatureFlag(
                 id,