EnableElastiCache.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.config.annotation;

import org.springframework.cache.annotation.EnableCaching;
import org.springframework.context.annotation.AdviceMode;
import org.springframework.context.annotation.Import;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * Annotation that enables caching based on the ElastiCache caching service. This annotation is
 * a meta-annotation of {@link org.springframework.cache.annotation.EnableCaching} with the same
 * configuration attributes. In contrast to the {@link org.springframework.cache.annotation.EnableCaching}
 * annotation this annotation does not require a {@link org.springframework.cache.annotation.CachingConfigurer}
 * instance, because it is provided by this annotation itself. Therefore users only need to add this annotation
 * into one configuration file and configure the necessary cache names.
 *
 * If there is no {@link org.springframework.cloud.aws.cache.config.annotation.EnableElastiCache#value()} ()} attribute
 * configured, then all caches inside a stack (if the application is running in one stack) will be used.
 *
 * @author Agim Emruli
 */
@EnableCaching
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
@Import(ElastiCacheCachingConfiguration.class)
public @interface EnableElastiCache {

    /**
     * Configures the cache clusters for the caching configuration. Support one or multiple caches
     * {@link org.springframework.cloud.aws.cache.config.annotation.CacheClusterConfig} configurations with their
     * physical cache name (as configured in the ElastiCache service) or their logical
     * cache name if the caches are configured inside a stack and
     * {@link org.springframework.cloud.aws.context.config.annotation.EnableStackConfiguration} annotation
     * is used inside the application.
     *
     * The CacheClusterConfig annotation also configures cache specific attributes like the expiration time.
     *
     * @return - the configured cache instances for the application.
     */
    CacheClusterConfig[] value() default {};

    /**
     * Indicate whether subclass-based (CGLIB) proxies are to be created as opposed
     * to standard Java interface-based proxies. The default is {@code false}. <strong>
     * Applicable only if {@link #mode()} is set to {@link AdviceMode#PROXY}</strong>.
     * <p>Note that setting this attribute to {@code true} will affect <em>all</em>
     * Spring-managed beans requiring proxying, not just those marked with
     * {@code @Cacheable}. For example, other beans marked with Spring's
     * {@code @Transactional} annotation will be upgraded to subclass proxying at the same
     * time. This approach has no negative impact in practice unless one is explicitly
     * expecting one type of proxy vs another, e.g. in tests.
     */
    boolean proxyTargetClass() default false;

    /**
     * Indicate how caching advice should be applied. The default is
     * {@link AdviceMode#PROXY}.
     *
     * @see AdviceMode
     */
    AdviceMode mode() default AdviceMode.PROXY;

    /**
     * Configures the default expiration time in seconds if there is no custom expiration time configuration with a
     * {@link org.springframework.cloud.aws.cache.config.annotation.CacheClusterConfig} configuration for the cache. The
     * expiration time is implementation specific (e.g. Redis or Memcached) and could therefore differ in the behaviour
     * based on the cache implementation.
     *
     * @return - the default expiration time for all caches that do not contain a specific expiration time on cache level
     */
    int defaultExpiration() default 0;
}