| package org.apache.helix.monitoring.mbeans.dynamicMBeans; |
| |
| /* |
| * 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. |
| */ |
| |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.HashSet; |
| import java.util.Set; |
| import javax.management.MBeanAttributeInfo; |
| |
| import org.apache.helix.monitoring.mbeans.exception.MetricException; |
| |
| |
| /** |
| * The abstract class for dynamic metrics that is used to emitting monitor data to DynamicMBean. |
| * |
| * @param <O> the type of metric object to initialize DynamicMetric |
| * @param <T> the type of monitor data |
| * Note that monitor data type can be different from the metric object type. |
| */ |
| public abstract class DynamicMetric<O, T> { |
| protected static final String DEFAULT_ATTRIBUTE_DESCRIPTION = "Attribute exposed for management"; |
| |
| private final Set<MBeanAttributeInfo> _attributeInfoSet; |
| private O _metricObject; |
| |
| /** |
| * Instantiates a new Dynamic metric. |
| * |
| * @param metricName the metric name |
| * @param metricObject the metric object |
| */ |
| public DynamicMetric(String metricName, O metricObject) { |
| if (metricName == null || metricObject == null) { |
| throw new MetricException("Failed to construct metric due to missing argument."); |
| } |
| _metricObject = metricObject; |
| _attributeInfoSet = |
| Collections.unmodifiableSet(generateAttributeInfos(metricName, metricObject)); |
| } |
| |
| /** |
| * @return the attribute infos that are exposed in the DynamicMBean |
| */ |
| public Collection<MBeanAttributeInfo> getAttributeInfos() { |
| return _attributeInfoSet; |
| } |
| |
| /** |
| * @param attributeName the attribute name |
| * @return the attribute value to update DynamicMBean |
| */ |
| public abstract Object getAttributeValue(String attributeName); |
| |
| /** |
| * @param newValue new value to update the DynamicMetric |
| */ |
| public abstract void updateValue(T newValue); |
| |
| /** |
| * Generate attribute infos set based on the input parameters |
| * Override this method if the monitor data will be exposed into different attributes |
| * |
| * @param metricName the metric name |
| * @param metricObject the metric object |
| * @return the MBeanAttributeInfo set |
| */ |
| protected Set<MBeanAttributeInfo> generateAttributeInfos(String metricName, O metricObject) { |
| Set<MBeanAttributeInfo> attributeInfoSet = new HashSet<>(); |
| attributeInfoSet.add(new MBeanAttributeInfo(metricName, metricObject.getClass().getName(), |
| DEFAULT_ATTRIBUTE_DESCRIPTION, true, false, false)); |
| return attributeInfoSet; |
| } |
| |
| /** |
| * Gets metric object. |
| * |
| * @return the metric object |
| */ |
| protected O getMetricObject() { |
| return _metricObject; |
| } |
| |
| /** |
| * Sets metric object. |
| * |
| * @param metricObject the metric object |
| */ |
| protected void setMetricObject(O metricObject) { |
| _metricObject = metricObject; |
| } |
| } |
| |