corner.cache.services.impl.CacheableDefinitionParserImpl.java Source code

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Here is the source code for corner.cache.services.impl.CacheableDefinitionParserImpl.java

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/* 
 * Copyright 2009 The Corner Team.
 * 
 * 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.
 */
package corner.cache.services.impl;

import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.codec.digest.DigestUtils;
import org.apache.tapestry5.ValueEncoder;
import org.apache.tapestry5.ioc.Invocation;
import org.apache.tapestry5.services.ValueEncoderSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.StringUtils;

import corner.cache.annotations.CacheKeyParameter;
import corner.cache.annotations.CacheNsParameter;
import corner.cache.annotations.Cacheable;
import corner.cache.services.CacheManager;
import corner.cache.services.CacheStrategy;
import corner.cache.services.CacheStrategySource;
import corner.cache.services.CacheableDefinitionParser;
import corner.cache.services.impl.CacheableDefine.Definition;
import corner.cache.services.impl.CacheableDefine.Definition.Builder;
import corner.orm.services.EntityService;

/**
 * ?
 * @author <a href="mailto:jun.tsai@gmail.com">Jun Tsai</a>
 * @version $Revision$
 * @since 3.1
 */
public class CacheableDefinitionParserImpl implements CacheableDefinitionParser {

    private ValueEncoderSource valueEncoderSource;
    private CacheManager cacheManager;
    private CacheStrategySource source;
    private Logger logger = LoggerFactory.getLogger(CacheableDefinitionParserImpl.class);
    private EntityService entityService;

    public CacheableDefinitionParserImpl(ValueEncoderSource valueEncoderSource, CacheManager cacheManager,
            CacheStrategySource source, EntityService entityService) {
        this.valueEncoderSource = valueEncoderSource;
        this.cacheManager = cacheManager;
        this.source = source;
        this.entityService = entityService;
    }

    /**
     * @see corner.cache.services.CacheableDefinitionParser#parseAsKey(org.apache.tapestry5.ioc.Invocation, java.lang.reflect.Method, corner.cache.services.CacheManager)
     */
    @Override
    public String parseAsKey(Invocation invocation, Method method) {
        Cacheable cacheable = method.getAnnotation(Cacheable.class);
        if (cacheable == null) {
            return null;
        }
        Definition define = null;
        //if (define == null) { // ?
        Builder defineBuilder = CacheableDefine.Definition.newBuilder();
        Annotation[][] parametersAnnotations = method.getParameterAnnotations();
        for (int i = 0; i < parametersAnnotations.length; i++) {
            Annotation[] pa = parametersAnnotations[i];
            for (Annotation a : pa) {
                if (a instanceof CacheKeyParameter) {
                    defineBuilder.addParameterIndex(i);
                }
            }
        }
        define = defineBuilder.build();

        // ?
        List<String> keyParameter = new ArrayList<String>();
        Object pObj;
        Class pType;
        for (int i = 0; i < define.getParameterIndexCount(); i++) {
            int pIndex = define.getParameterIndex(i);
            pObj = invocation.getParameter(pIndex);
            pType = null;
            if (pObj != null) {
                pType = entityService.getEntityClass(pObj);
            }
            if (pType == null) {
                pType = method.getParameterTypes()[pIndex];
            }
            ValueEncoder encoder = valueEncoderSource.getValueEncoder(pType);
            keyParameter.add(encoder.toClient(pObj));
        }
        //key
        String key = null;
        String keyFormat = cacheable.keyFormat();
        logger.debug("key parameter:{}", keyParameter);
        if (!StringUtils.hasText(keyFormat)) {
            key = DigestUtils.shaHex(method.toString() + keyParameter.toString());
        } else {
            key = String.format(keyFormat, keyParameter.toArray(new Object[0]));
        }

        CacheStrategy strategy = this.source.findStrategy(cacheable.strategy());
        CacheNsParameter[] nses = cacheable.namespaces();
        if (strategy == null) {
            throw new RuntimeException("fail to find cache strategy instance!");
        }
        return strategy.appendNamespace(cacheManager, cacheable.clazz(), nses, key, keyParameter.toArray());
    }

}