Java tutorial
/* * Copyright (C) 2009 Water Services Regulation Authority (Ofwat) * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ package uk.gov.ofwat.fountain.aspect.cache.dao.generic; import java.util.Collections; import java.util.Map; import org.apache.commons.collections.map.LRUMap; import org.aspectj.lang.ProceedingJoinPoint; import org.aspectj.lang.annotation.Around; import org.aspectj.lang.annotation.Aspect; import org.springframework.aop.support.AopUtils; import org.springframework.core.annotation.Order; import uk.gov.ofwat.fountain.aspect.cache.dao.DaoCache; import uk.gov.ofwat.fountain.domain.Entity; @Aspect("perthis(uk.gov.ofwat.fountain.aspect.cache.dao.DaoCache.findByIdEntityPC() || " + "uk.gov.ofwat.fountain.aspect.cache.dao.DaoCache.deleteEntityPC()) ||" + "uk.gov.ofwat.fountain.aspect.cache.dao.DaoCache.updateEntityPC()") @Order(215) public class FindByIdAspect extends DaoCache { private Map<Integer, Object> cacheOnId; public Map getCache() { return cacheOnId; } public void setCache(Map cache) { cacheOnId = cache; } @SuppressWarnings("unchecked") @Around("uk.gov.ofwat.fountain.aspect.cache.dao.DaoCache.findByIdEntityPC()") public Object cacheOnFindByID(ProceedingJoinPoint pjp) throws Throwable { if (!isEnabled()) { return pjp.proceed(); } if (null == getCache()) { initialiseCache(pjp.getTarget().getClass()); } Object[] args = pjp.getArgs(); Integer key = (Integer) args[0]; Object retVal = null; if (cacheOnId.containsKey(key)) { retVal = cacheOnId.get(key); } else { retVal = pjp.proceed(); cacheOnId.put(key, retVal); incrementCache(pjp); } return retVal; } @Around("uk.gov.ofwat.fountain.aspect.cache.dao.DaoCache.deleteEntityPC()") public void removeFromCacheOnDelete(ProceedingJoinPoint pjp) throws Throwable { if (!isEnabled()) { pjp.proceed(); return; } Object[] args = pjp.getArgs(); if (null != cacheOnId) { Integer key = (Integer) args[0]; pjp.proceed(args); cacheOnId.remove(key); } else { pjp.proceed(args); } } @Around("uk.gov.ofwat.fountain.aspect.cache.dao.DaoCache.updateEntityPC()") public void removeFromCacheOnUpdate(ProceedingJoinPoint pjp) throws Throwable { Object[] args = pjp.getArgs(); if (null != cacheOnId) { Entity entity = (Entity) args[0]; Integer key = entity.getId(); pjp.proceed(args); cacheOnId.remove(key); } else { pjp.proceed(args); } } }