Github user srdo commented on a diff in the pull request:
https://github.com/apache/storm/pull/2790#discussion_r208577649
--- Diff:
external/storm-kafka-client/src/main/java/org/apache/storm/kafka/bolt/PreparableCallback.java
---
@@ -0,0 +1,32 @@
+/**
+ * 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.storm.kafka.bolt;
+
+import java.io.Serializable;
+import java.util.Map;
+
+import org.apache.kafka.clients.producer.Callback;
+import org.apache.storm.task.TopologyContext;
+
+/**
+ * Serializable callback for use with the KafkaProducer on KafkaBolt.
+ */
+public interface PreparableCallback extends Callback, Serializable {
+ void prepare(Map<String, Object> topoConf, TopologyContext context);
--- End diff --
I'm a little unsure what you're asking. It's an extension of the Kafka
Callback interface, which adds the prepare method that fits Storm.
---