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.metrics2; import java.util.Collection; import org.apache.hadoop.classification.InterfaceAudience; import org.apache.hadoop.classification.InterfaceStability; /** * An immutable snapshot of metrics with a timestamp */ @InterfaceAudience.Public @InterfaceStability.Evolving public interface MetricsRecord { /** * Get the timestamp of the metrics * @return the timestamp */ long timestamp(); /** * @return the metrics record name */ String name(); /** * @return the description of the metrics record */ String description(); /** * @return the context name of the metrics record */ String context(); /** * Get the tags of the record * Note: returning a collection instead of iterable as we * need to use tags as keys (hence Collection#hashCode etc.) in maps * @return an unmodifiable collection of tags */ Collection<MetricsTag> tags(); /** * Get the metrics of the record * @return an immutable iterable interface for metrics */ Iterable<AbstractMetric> metrics(); }