Adressing comments

core/src/main/java/org/elasticsearch/search/aggregations/bucket/filters/FiltersAggregator.java

@@ -57,7 +57,7 @@ public class FiltersAggregator extends BucketsAggregator {
     public static final ParseField OTHER_BUCKET_FIELD = new ParseField("other_bucket");
     public static final ParseField OTHER_BUCKET_KEY_FIELD = new ParseField("other_bucket_key");
 
-    public static class KeyedFilter implements Writeable<KeyedFilter>, ToXContent, Comparable<KeyedFilter> {
+    public static class KeyedFilter implements Writeable<KeyedFilter>, ToXContent {
 
         static final KeyedFilter PROTOTYPE = new KeyedFilter("", EmptyQueryBuilder.PROTOTYPE);
         private final String key;
@@ -122,11 +122,6 @@ public class FiltersAggregator extends BucketsAggregator {
             return Objects.equals(key, other.key)
                     && Objects.equals(filter, other.filter);
         }
-
-        @Override
-        public int compareTo(KeyedFilter o) {
-            return this.key.compareTo(o.key);
-        }
     }
 
     private final String[] keys;

core/src/main/java/org/elasticsearch/search/aggregations/bucket/filters/FiltersAggregatorBuilder.java

@@ -59,7 +59,7 @@ public class FiltersAggregatorBuilder extends AggregatorBuilder<FiltersAggregato
     private FiltersAggregatorBuilder(String name, List<KeyedFilter> filters) {
         super(name, InternalFilters.TYPE);
         // internally we want to have a fixed order of filters, regardless of the order of the filters in the request
-        Collections.sort(filters);
+        Collections.sort(filters, (KeyedFilter kf1, KeyedFilter kf2) -> kf1.key().compareTo(kf2.key()));
         this.filters = filters;
         this.keyed = true;
     }

core/src/test/java/org/elasticsearch/search/aggregations/bucket/FiltersIT.java

@@ -34,7 +34,9 @@ import org.elasticsearch.test.ESIntegTestCase;
 import org.hamcrest.Matchers;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 
@@ -488,13 +490,9 @@ public class FiltersIT extends ESIntegTestCase {
     }
 
     private static KeyedFilter[] randomOrder(KeyedFilter... filters) {
-        for (int i = 0; i < filters.length; i++) {
-            KeyedFilter tmp = filters[i];
-            int index = randomInt(filters.length - 1);
-            filters[i] = filters[index];
-            filters[index] = tmp;
-        }
-        return filters;
+        List<KeyedFilter> asList = Arrays.asList(filters);
+        Collections.shuffle(asList);
+        return asList.toArray(new KeyedFilter[filters.length]);
     }
 
 }