ElastiCacheFactoryBean.java

/*
 * Copyright 2013-2014 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 org.springframework.cloud.aws.cache;

import com.amazonaws.services.elasticache.AmazonElastiCache;
import com.amazonaws.services.elasticache.model.CacheCluster;
import com.amazonaws.services.elasticache.model.DescribeCacheClustersRequest;
import com.amazonaws.services.elasticache.model.DescribeCacheClustersResult;
import com.amazonaws.services.elasticache.model.Endpoint;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.config.AbstractFactoryBean;
import org.springframework.cache.Cache;
import org.springframework.cloud.aws.core.env.ResourceIdResolver;

import java.util.List;

/**
 * @author Agim Emruli
 */
public class ElastiCacheFactoryBean extends AbstractFactoryBean<Cache> {

    private static final Logger LOGGER = LoggerFactory.getLogger(ElastiCacheFactoryBean.class);

    private final AmazonElastiCache amazonElastiCache;
    private final String cacheClusterId;
    private final ResourceIdResolver resourceIdResolver;
    private final List<? extends CacheFactory> cacheFactories;

    public ElastiCacheFactoryBean(AmazonElastiCache amazonElastiCache, String cacheClusterId,
                                  ResourceIdResolver resourceIdResolver, List<? extends CacheFactory> cacheFactories) {
        this.amazonElastiCache = amazonElastiCache;
        this.resourceIdResolver = resourceIdResolver;
        this.cacheClusterId = cacheClusterId;
        this.cacheFactories = cacheFactories;
    }

    public ElastiCacheFactoryBean(AmazonElastiCache amazonElastiCache, String cacheClusterId, List<CacheFactory> cacheFactories) {
        this(amazonElastiCache, cacheClusterId, null, cacheFactories);
    }

    @Override
    public Class<Cache> getObjectType() {
        return Cache.class;
    }

    @Override
    protected Cache createInstance() throws Exception {
        DescribeCacheClustersRequest describeCacheClustersRequest = new DescribeCacheClustersRequest().withCacheClusterId(getCacheClusterName());
        describeCacheClustersRequest.setShowCacheNodeInfo(true);

        DescribeCacheClustersResult describeCacheClustersResult = this.amazonElastiCache.describeCacheClusters(describeCacheClustersRequest);

        CacheCluster cacheCluster = describeCacheClustersResult.getCacheClusters().get(0);
        if (!"available".equals(cacheCluster.getCacheClusterStatus())) {
            LOGGER.warn("Cache cluster is not available now. Connection may fail during cache access. Current status is {}", cacheCluster.getCacheClusterStatus());
        }

        Endpoint configurationEndpoint = getEndpointForCache(cacheCluster);

        for (CacheFactory cacheFactory : this.cacheFactories) {
            if (cacheFactory.isSupportingCacheArchitecture(cacheCluster.getEngine())) {
                return cacheFactory.createCache(this.cacheClusterId, configurationEndpoint.getAddress(), configurationEndpoint.getPort());
            }
        }

        throw new IllegalArgumentException("No CacheFactory configured for engine: " + cacheCluster.getEngine());
    }

    @Override
    protected void destroyInstance(Cache instance) throws Exception {
        if (instance instanceof DisposableBean) {
            ((DisposableBean) instance).destroy();
        }
    }

    private String getCacheClusterName() {
        return this.resourceIdResolver != null ? this.resourceIdResolver.resolveToPhysicalResourceId(this.cacheClusterId) : this.cacheClusterId;
    }

    private static Endpoint getEndpointForCache(CacheCluster cacheCluster) {
        if (cacheCluster.getConfigurationEndpoint() != null) {
            return cacheCluster.getConfigurationEndpoint();
        }

        if (!cacheCluster.getCacheNodes().isEmpty()) {
            return cacheCluster.getCacheNodes().get(0).getEndpoint();
        }

        throw new IllegalArgumentException("No Configuration Endpoint or Cache Node available to " +
                "receive address information for cluster:'" + cacheCluster.getCacheClusterId() + "'");
    }
}