Github user cestella commented on a diff in the pull request:
https://github.com/apache/metron/pull/1022#discussion_r190966698
--- Diff:
metron-platform/metron-elasticsearch/src/main/java/org/apache/metron/elasticsearch/writer/SharedFieldNameConverterFactory.java
---
@@ -0,0 +1,72 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.metron.elasticsearch.writer;
+
+import org.apache.commons.lang.ClassUtils;
+import org.apache.commons.lang3.StringUtils;
+import org.apache.commons.lang3.exception.ExceptionUtils;
+import org.apache.metron.common.configuration.writer.WriterConfiguration;
+import org.apache.metron.common.field.FieldNameConverter;
+import org.apache.metron.common.field.FieldNameConverters;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.lang.invoke.MethodHandles;
+
+/**
+ * A {@link FieldNameConverterFactory} that returns instances of {@link
FieldNameConverter}
+ * that are shared and reused.
+ *
+ * <p>The instances are created and managed by the {@link
FieldNameConverters} class.
+ */
+public class SharedFieldNameConverterFactory implements
FieldNameConverterFactory {
+
--- End diff --
This looks like it's moving in the right direction, but as @mmiklavc gave
an example for, why would we not replace this class with a `static
create(String sensorType, WriterConfig config)` method on the enum?
---