Java tutorial
/** * 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.hadoop.mapreduce.jobhistory; import java.util.Set; import org.apache.hadoop.classification.InterfaceAudience; import org.apache.hadoop.classification.InterfaceStability; import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEvent; import org.apache.hadoop.yarn.api.records.timelineservice.TimelineMetric; /** * Interface for event wrapper classes. Implementations each wrap an * Avro-generated class, adding constructors and accessor methods. */ @InterfaceAudience.Private @InterfaceStability.Unstable public interface HistoryEvent { /** Return this event's type. */ EventType getEventType(); /** Return the Avro datum wrapped by this. */ Object getDatum(); /** Set the Avro datum wrapped by this. */ void setDatum(Object datum); /** * Map HistoryEvent to TimelineEvent. * * @return the timeline event */ TimelineEvent toTimelineEvent(); /** * Counters or Metrics if any else return null. * * @return the set of timeline metrics */ Set<TimelineMetric> getTimelineMetrics(); }