separated out logging of errors to separate overridable method in DefaultGraphQLErrorHandler so that entire processErrors method does not need to be overridden just to change which errors get logged by users of DefaultGraphQLErrorHandler

Author: bsara

src/main/java/graphql/servlet/DefaultGraphQLErrorHandler.java

@@ -26,20 +26,22 @@ public List<GraphQLError> processErrors(List<GraphQLError> errors) {
 
             errors.stream()
                     .filter(error -> !isClientError(error))
-                    .forEach(error -> {
-                        if (error instanceof Throwable) {
-                            log.error("Error executing query!", (Throwable) error);
-                        } else if (error instanceof ExceptionWhileDataFetching) {
-                            log.error("Error executing query {}", error.getMessage(), ((ExceptionWhileDataFetching) error).getException());
-                        } else {
-                            log.error("Error executing query ({}): {}", error.getClass().getSimpleName(), error.getMessage());
-                        }
-                    });
+                    .forEach(this::logError);
         }
 
         return clientErrors;
     }
 
+    protected void logError(GraphQLError error) {
+        if (error instanceof Throwable) {
+            log.error("Error executing query!", (Throwable) error);
+        } else if (error instanceof ExceptionWhileDataFetching) {
+            log.error("Error executing query {}", error.getMessage(), ((ExceptionWhileDataFetching) error).getException());
+        } else {
+            log.error("Error executing query ({}): {}", error.getClass().getSimpleName(), error.getMessage());
+        }
+    }
+
     protected List<GraphQLError> filterGraphQLErrors(List<GraphQLError> errors) {
         return errors.stream()
                 .filter(this::isClientError)