Java tutorial
/* * #%L * ACS AEM Commons Bundle * %% * Copyright (C) 2015 Adobe * %% * Licensed 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. * #L% */ package com.adobe.acs.commons.util.impl; import java.util.HashMap; import java.util.Map; import java.util.concurrent.ConcurrentMap; import javax.management.NotCompliantMBeanException; import javax.management.openmbean.CompositeDataSupport; import javax.management.openmbean.CompositeType; import javax.management.openmbean.OpenDataException; import javax.management.openmbean.OpenType; import javax.management.openmbean.SimpleType; import javax.management.openmbean.TabularData; import javax.management.openmbean.TabularDataSupport; import javax.management.openmbean.TabularType; import org.apache.commons.io.FileUtils; import org.apache.commons.lang.StringUtils; import com.adobe.granite.jmx.annotation.AnnotatedStandardMBean; import com.google.common.cache.Cache; import com.google.common.cache.CacheStats; public abstract class AbstractGuavaCacheMBean<K, V> extends AnnotatedStandardMBean implements GenericCacheMBean { public <T> AbstractGuavaCacheMBean(T implementation, Class<T> mbeanInterface) throws NotCompliantMBeanException { super(implementation, mbeanInterface); } protected AbstractGuavaCacheMBean(Class<?> mbeanInterface) throws NotCompliantMBeanException { super(mbeanInterface); } protected abstract Cache<K, V> getCache(); protected abstract long getBytesLength(V cacheObj); protected abstract void addCacheData(Map<String, Object> data, V cacheObj); protected abstract String toString(V cacheObj) throws Exception; protected abstract CompositeType getCacheEntryType() throws OpenDataException; @Override public final void clearCache() { getCache().invalidateAll(); } @Override public final long getCacheEntriesCount() { return getCache().size(); } @Override public final String getCacheSize() { // Iterate through the cache entries and compute the total size of byte array. long size = 0L; ConcurrentMap<K, V> cacheAsMap = getCache().asMap(); for (final Map.Entry<K, V> entry : cacheAsMap.entrySet()) { size += getBytesLength(entry.getValue()); } // Convert bytes to human-friendly format return FileUtils.byteCountToDisplaySize(size); } @Override @SuppressWarnings("squid:S1192") public final TabularData getCacheStats() throws OpenDataException { // Exposing all google guava stats. final CompositeType cacheEntryType = new CompositeType("Cache Stats", "Cache Stats", new String[] { "Stat", "Value" }, new String[] { "Stat", "Value" }, new OpenType[] { SimpleType.STRING, SimpleType.STRING }); final TabularDataSupport tabularData = new TabularDataSupport( new TabularType("Cache Stats", "Cache Stats", cacheEntryType, new String[] { "Stat" })); CacheStats cacheStats = getCache().stats(); final Map<String, Object> row = new HashMap<String, Object>(); row.put("Stat", "Request Count"); row.put("Value", String.valueOf(cacheStats.requestCount())); tabularData.put(new CompositeDataSupport(cacheEntryType, row)); row.put("Stat", "Hit Count"); row.put("Value", String.valueOf(cacheStats.hitCount())); tabularData.put(new CompositeDataSupport(cacheEntryType, row)); row.put("Stat", "Hit Rate"); row.put("Value", String.format("%.0f%%", cacheStats.hitRate() * 100)); tabularData.put(new CompositeDataSupport(cacheEntryType, row)); row.put("Stat", "Miss Count"); row.put("Value", String.valueOf(cacheStats.missCount())); tabularData.put(new CompositeDataSupport(cacheEntryType, row)); row.put("Stat", "Miss Rate"); row.put("Value", String.format("%.0f%%", cacheStats.missRate() * 100)); tabularData.put(new CompositeDataSupport(cacheEntryType, row)); row.put("Stat", "Eviction Count"); row.put("Value", String.valueOf(cacheStats.evictionCount())); tabularData.put(new CompositeDataSupport(cacheEntryType, row)); row.put("Stat", "Load Count"); row.put("Value", String.valueOf(cacheStats.loadCount())); tabularData.put(new CompositeDataSupport(cacheEntryType, row)); row.put("Stat", "Load Exception Count"); row.put("Value", String.valueOf(cacheStats.loadExceptionCount())); tabularData.put(new CompositeDataSupport(cacheEntryType, row)); row.put("Stat", "Load Exception Rate"); row.put("Value", String.format("%.0f%%", cacheStats.loadExceptionRate() * 100)); tabularData.put(new CompositeDataSupport(cacheEntryType, row)); row.put("Stat", "Load Success Count"); row.put("Value", String.valueOf(cacheStats.loadSuccessCount())); tabularData.put(new CompositeDataSupport(cacheEntryType, row)); row.put("Stat", "Average Load Penalty"); row.put("Value", String.valueOf(cacheStats.averageLoadPenalty())); tabularData.put(new CompositeDataSupport(cacheEntryType, row)); row.put("Stat", "Total Load Time"); row.put("Value", String.valueOf(cacheStats.totalLoadTime())); tabularData.put(new CompositeDataSupport(cacheEntryType, row)); return tabularData; } @Override public final TabularData getCacheContents() throws OpenDataException { final CompositeType cacheEntryType = getCacheEntryType(); final TabularDataSupport tabularData = new TabularDataSupport( new TabularType("Cache Entries", "Cache Entries", cacheEntryType, new String[] { "Cache Key" })); ConcurrentMap<K, V> cacheAsMap = getCache().asMap(); for (final Map.Entry<K, V> entry : cacheAsMap.entrySet()) { final Map<String, Object> data = new HashMap<String, Object>(); data.put("Cache Key", entry.getKey().toString()); V cacheObj = entry.getValue(); if (cacheObj != null) { addCacheData(data, cacheObj); } tabularData.put(new CompositeDataSupport(cacheEntryType, data)); } return tabularData; } @Override public String getCacheEntry(String cacheKeyStr) throws Exception { K cacheKey = null; for (K cacheKeyTmp : getCache().asMap().keySet()) { if (StringUtils.equals(cacheKeyStr, cacheKeyTmp.toString())) { cacheKey = cacheKeyTmp; break; } } if (cacheKey != null) { V persistenceObject = getCache().getIfPresent(cacheKey); if (persistenceObject != null) { return toString(persistenceObject); } } return "Invalid cache key parameter."; } }