Java tutorial
/* * Copyright (c) 2011-2013 Flite, Inc * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package org.flite.cach3.aop; import net.spy.memcached.MemcachedClientIF; import net.spy.memcached.transcoders.IntegerTranscoder; import net.spy.memcached.transcoders.LongTranscoder; import org.apache.commons.lang.StringUtils; import org.aspectj.lang.JoinPoint; import org.aspectj.lang.annotation.AfterReturning; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.annotation.Pointcut; import org.flite.cach3.annotations.AnnotationConstants; import org.flite.cach3.annotations.UpdateMultiCache; import org.flite.cach3.annotations.UpdateSingleCache; import org.flite.cach3.annotations.groups.UpdateSingleCaches; import org.flite.cach3.api.CacheConditionally; import org.flite.cach3.api.UpdateSingleCacheListener; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.core.Ordered; import org.springframework.core.annotation.Order; import java.lang.reflect.Method; import java.security.InvalidParameterException; import java.util.Arrays; import java.util.List; @Aspect @Order(Ordered.HIGHEST_PRECEDENCE / 2) public class UpdateSingleCacheAdvice extends CacheBase { private static final Logger LOG = LoggerFactory.getLogger(UpdateSingleCacheAdvice.class); @Pointcut("@annotation(org.flite.cach3.annotations.UpdateSingleCache)") public void updateSingle() { } @AfterReturning(pointcut = "updateSingle()", returning = "retVal") public Object cacheUpdateSingle(final JoinPoint jp, final Object retVal) throws Throwable { try { doUpdate(jp, retVal); } catch (Throwable ex) { if (LOG.isDebugEnabled()) { LOG.warn("Caching on " + jp.toShortString() + " aborted due to an error.", ex); } else { LOG.warn("Caching on " + jp.toShortString() + " aborted due to an error: " + ex.getMessage()); } } return retVal; } @Pointcut("@annotation(org.flite.cach3.annotations.groups.UpdateSingleCaches)") public void updateSingles() { } @AfterReturning(pointcut = "updateSingles()", returning = "retVal") public Object cacheUpdateSingles(final JoinPoint jp, final Object retVal) throws Throwable { try { doUpdate(jp, retVal); } catch (Throwable ex) { if (LOG.isDebugEnabled()) { LOG.warn("Caching on " + jp.toShortString() + " aborted due to an error.", ex); } else { LOG.warn("Caching on " + jp.toShortString() + " aborted due to an error: " + ex.getMessage()); } } return retVal; } private void doUpdate(final JoinPoint jp, final Object retVal) throws Throwable { if (isCacheDisabled()) { LOG.debug("Caching is disabled."); return; } final MemcachedClientIF cache = getMemcachedClient(); final Method methodToCache = getMethodToCache(jp); List<UpdateSingleCache> lAnnotations; if (methodToCache.getAnnotation(UpdateSingleCache.class) != null) { lAnnotations = Arrays.asList(methodToCache.getAnnotation(UpdateSingleCache.class)); } else { lAnnotations = Arrays.asList(methodToCache.getAnnotation(UpdateSingleCaches.class).value()); } for (int i = 0; i < lAnnotations.size(); i++) { // This is injected caching. If anything goes wrong in the caching, LOG the crap outta it, // but do not let it surface up past the AOP injection itself. try { final AnnotationInfo info = getAnnotationInfo(lAnnotations.get(i), methodToCache.getName(), getJitterDefault()); final String baseKey = CacheBase.getBaseKey(info.getAsString(AType.KEY_TEMPLATE), info.getAsInteger(AType.KEY_INDEX, null), retVal, jp.getArgs(), methodToCache.toString(), factory, methodStore); final String cacheKey = buildCacheKey(baseKey, info.getAsString(AType.NAMESPACE), info.getAsString(AType.KEY_PREFIX)); Object dataObject = getIndexObject(info.getAsInteger(AType.DATA_INDEX, null), retVal, jp.getArgs(), methodToCache.toString()); dataObject = UpdateSingleCacheAdvice.getMergedData(dataObject, info.getAsString(AType.DATA_TEMPLATE, null), retVal, jp.getArgs(), factory); final Class dataTemplateType = (Class) info.getAsType(AType.DATA_TEMPLATE_TYPE, String.class); final Object submission = (dataObject == null) ? new PertinentNegativeNull() : applyDataTemplateType(dataObject, dataTemplateType); boolean cacheable = true; if (submission instanceof CacheConditionally) { cacheable = ((CacheConditionally) submission).isCacheable(); } if (cacheable) { cache.set(cacheKey, calculateJitteredExpiration(info.getAsInteger(AType.EXPIRATION), info.getAsInteger(AType.JITTER)), submission); } // Notify the observers that a cache interaction happened. final List<UpdateSingleCacheListener> listeners = getPertinentListeners( UpdateSingleCacheListener.class, info.getAsString(AType.NAMESPACE)); if (listeners != null && !listeners.isEmpty()) { for (final UpdateSingleCacheListener listener : listeners) { try { listener.triggeredUpdateSingleCache(info.getAsString(AType.NAMESPACE), info.getAsString(AType.KEY_PREFIX, null), baseKey, dataObject, retVal, jp.getArgs()); } catch (Exception ex) { LOG.warn("Problem when triggering a listener.", ex); } } } } catch (Exception ex) { if (LOG.isDebugEnabled()) { LOG.warn("Caching on " + jp.toShortString() + " aborted due to an error.", ex); } else { LOG.warn("Caching on " + jp.toShortString() + " aborted due to an error: " + ex.getMessage()); } } } } /*default*/ static AnnotationInfo getAnnotationInfo(final UpdateSingleCache annotation, final String targetMethodName, final int jitterDefault) { final AnnotationInfo result = new AnnotationInfo(); if (annotation == null) { throw new InvalidParameterException( String.format("No annotation of type [%s] found.", UpdateSingleCache.class.getName())); } final String namespace = annotation.namespace(); if (AnnotationConstants.DEFAULT_STRING.equals(namespace) || namespace == null || namespace.length() < 1) { throw new InvalidParameterException( String.format("Namespace for annotation [%s] must be defined on [%s]", UpdateSingleCache.class.getName(), targetMethodName)); } result.add(new AType.Namespace(namespace)); final String keyPrefix = annotation.keyPrefix(); if (!AnnotationConstants.DEFAULT_STRING.equals(keyPrefix)) { if (StringUtils.isBlank(keyPrefix)) { throw new InvalidParameterException(String.format( "KeyPrefix for annotation [%s] must not be defined as an empty string on [%s]", UpdateSingleCache.class.getName(), targetMethodName)); } result.add(new AType.KeyPrefix(keyPrefix)); } final Integer keyIndex = annotation.keyIndex(); if (keyIndex != AnnotationConstants.DEFAULT_KEY_INDEX && keyIndex < -1) { throw new InvalidParameterException( String.format("KeyIndex for annotation [%s] must be -1 or greater on [%s]", UpdateSingleCache.class.getName(), targetMethodName)); } final boolean keyIndexDefined = keyIndex >= -1; final String keyTemplate = annotation.keyTemplate(); if (StringUtils.isBlank(keyTemplate)) { throw new InvalidParameterException( String.format("KeyTemplate for annotation [%s] must not be defined as an empty string on [%s]", UpdateSingleCache.class.getName(), targetMethodName)); } final boolean keyTemplateDefined = !AnnotationConstants.DEFAULT_STRING.equals(keyTemplate); if (keyIndexDefined == keyTemplateDefined) { throw new InvalidParameterException(String.format( "Exactly one of [keyIndex,keyTemplate] must be defined for annotation [%s] on [%s]", UpdateSingleCache.class.getName(), targetMethodName)); } if (keyIndexDefined) { result.add(new AType.KeyIndex(keyIndex)); } if (keyTemplateDefined) { result.add(new AType.KeyTemplate(keyTemplate)); } final int dataIndex = annotation.dataIndex(); if (dataIndex < -1) { throw new InvalidParameterException( String.format("DataIndex for annotation [%s] must be -1 or greater on [%s]", UpdateSingleCache.class.getName(), targetMethodName)); } result.add(new AType.DataIndex(dataIndex)); final String dataTemplate = annotation.dataTemplate(); if (!AnnotationConstants.DEFAULT_STRING.equals(dataTemplate)) { if (StringUtils.isBlank(dataTemplate)) { throw new InvalidParameterException(String.format( "DataTemplate for annotation [%s] must not be defined as an empty string on [%s]", UpdateMultiCache.class.getName(), targetMethodName)); } result.add(new AType.DataTemplate(dataTemplate)); } final Class dataTemplateType = annotation.dataTemplateType(); if (!String.class.equals(dataTemplateType)) { result.add(new AType.DataTemplateType(dataTemplateType)); } final int expiration = annotation.expiration(); if (expiration < 0) { throw new InvalidParameterException( String.format("Expiration for annotation [%s] must be 0 or greater on [%s]", UpdateSingleCache.class.getName(), targetMethodName)); } result.add(new AType.Expiration(expiration)); final int jitter = annotation.jitter(); if (jitter < -1 || jitter > 99) { throw new InvalidParameterException( String.format("Jitter for annotation [%s] must be -1 <= jitter <= 99 on [%s]", UpdateSingleCache.class.getName(), targetMethodName)); } result.add(new AType.Jitter(jitter == -1 ? jitterDefault : jitter)); return result; } }