com.icfcc.cache.annotation.AbstractCachingConfiguration.java Source code

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Here is the source code for com.icfcc.cache.annotation.AbstractCachingConfiguration.java

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/*
 * Copyright 2002-2011 the original author or authors.
 *
 * 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 com.icfcc.cache.annotation;

import com.icfcc.cache.interceptor.KeyGenerator;
import com.icfcc.cache.CacheManager;
import org.springframework.core.type.AnnotationMetadata;
import org.springframework.util.Assert;
import org.springframework.util.CollectionUtils;

import java.util.Collection;
import java.util.Map;

// import org.springframework.beans.factory.annotation.Autowired;
// import org.springframework.context.annotation.ImportAware;

/**
 * Abstract base {@code @Configuration} class providing common structure for enabling
 * Spring's annotation-driven cache management capability.
 *
 * @author Chris Beams
 * @since 3.1
 * @see EnableCaching
 */
//@Configuration
public abstract class AbstractCachingConfiguration {//implements ImportAware {

    /** Parsed annotation metadata for {@code @EnableCaching} on the importing class. */
    protected Map<String, Object> enableCaching;
    protected CacheManager cacheManager;
    protected KeyGenerator keyGenerator;

    //ixme @Autowired(required=false)
    private Collection<CacheManager> cacheManagerBeans;
    // @Autowired(required=false)
    private Collection<CachingConfigurer> cachingConfigurers;

    public void setImportMetadata(AnnotationMetadata importMetadata) {
        this.enableCaching = importMetadata.getAnnotationAttributes(EnableCaching.class.getName(), false);
        Assert.notNull(this.enableCaching,
                "@EnableCaching is not present on importing class " + importMetadata.getClassName());
    }

    /**
     * Determine which {@code CacheManager} bean to use. Prefer the result of
     * {@link CachingConfigurer#cacheManager()} over any by-type matching. If none, fall
     * back to by-type matching on {@code CacheManager}.
     * @throws IllegalArgumentException if no CacheManager can be found; if more than one
     * CachingConfigurer implementation exists; if multiple CacheManager beans and no
     * CachingConfigurer exists to disambiguate.
     */
    //@PostConstruct
    protected void reconcileCacheManager() {
        if (!CollectionUtils.isEmpty(cachingConfigurers)) {
            int nConfigurers = cachingConfigurers.size();
            if (nConfigurers > 1) {
                throw new IllegalStateException(nConfigurers + " implementations of "
                        + "CachingConfigurer were found when only 1 was expected. "
                        + "Refactor the configuration such that CachingConfigurer is "
                        + "implemented only once or not at all.");
            }
            CachingConfigurer cachingConfigurer = cachingConfigurers.iterator().next();
            this.cacheManager = cachingConfigurer.cacheManager();
            this.keyGenerator = cachingConfigurer.keyGenerator();
        } else if (!CollectionUtils.isEmpty(cacheManagerBeans)) {
            int nManagers = cacheManagerBeans.size();
            if (nManagers > 1) {
                throw new IllegalStateException(nManagers + " beans of type CacheManager "
                        + "were found when only 1 was expected. Remove all but one of the "
                        + "CacheManager bean definitions, or implement CachingConfigurer "
                        + "to make explicit which CacheManager should be used for "
                        + "annotation-driven cache management.");
            }
            CacheManager cacheManager = cacheManagerBeans.iterator().next();
            this.cacheManager = cacheManager;
            // keyGenerator remains null; will fall back to default within CacheInterceptor
        } else {
            throw new IllegalStateException("No bean of type CacheManager could be found. "
                    + "Register a CacheManager bean or remove the @EnableCaching annotation "
                    + "from your configuration.");
        }
    }
}