com.dianping.avatar.cache.interceptor.CacheInterceptor.java Source code

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Here is the source code for com.dianping.avatar.cache.interceptor.CacheInterceptor.java

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/**
 * Project: avatar
 * 
 * File Created at 2010-7-19
 * $Id$
 * 
 * Copyright 2010 Dianping.com Corporation Limited.
 * All rights reserved.
 *
 * This software is the confidential and proprietary information of
 * Dianping Company. ("Confidential Information").  You shall not
 * disclose such Confidential Information and shall use it only in
 * accordance with the terms of the license agreement you entered into
 * with Dianping.com.
 */
package com.dianping.avatar.cache.interceptor;

import java.lang.reflect.Method;

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.apache.commons.beanutils.MethodUtils;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.util.Assert;

import com.dianping.avatar.cache.CacheKey;
import com.dianping.avatar.cache.CacheService;
import com.dianping.avatar.cache.annotation.Cache;
import com.dianping.avatar.cache.annotation.CacheOperation;
import com.dianping.avatar.cache.util.CacheAnnotationUtils;

/**
 * CacheInterceptor to support {@link Cache} annotation
 * 
 * @author danson.liu
 * @author guoqing.chen
 * 
 */
public class CacheInterceptor implements MethodInterceptor, InitializingBean {
    /**
     * Cache service
     */
    private CacheService cacheService;

    @Override
    public Object invoke(MethodInvocation invocation) throws Throwable {
        Method method = invocation.getMethod();
        Cache cache = AnnotationUtils.findAnnotation(method, Cache.class);
        if (cache == null) {
            Class<? extends Object> targetClazz = invocation.getThis().getClass();
            method = MethodUtils.getAccessibleMethod(targetClazz, method.getName(), method.getParameterTypes());
            cache = AnnotationUtils.findAnnotation(method, Cache.class);
        }
        if (cache != null) {

            CacheOperation operation = cache.operation();

            CacheKey cacheKey = CacheAnnotationUtils.getCacheKey(method, invocation.getArguments());

            if (operation == CacheOperation.SetAndGet) {
                Object cachedItem = cacheService.get(cacheKey);

                if (cachedItem != null) {
                    return cachedItem;
                }

                Object item = invocation.proceed();
                // consider create an null object instead of null
                cacheService.add(cacheKey, item);

                return item;
            } else if (operation == CacheOperation.Update || operation == CacheOperation.Remove) {
                cacheService.remove(cacheKey);
                return invocation.proceed();
            }
        }
        return invocation.proceed();
    }

    public void setCacheService(CacheService cacheService) {
        this.cacheService = cacheService;
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        Assert.notNull(cacheService, "cacheService required.");
    }
}