001/*
002 * Copyright 2002-2018 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.cache.annotation;
018
019import java.util.ArrayList;
020import java.util.List;
021
022import org.springframework.context.annotation.AdviceMode;
023import org.springframework.context.annotation.AdviceModeImportSelector;
024import org.springframework.context.annotation.AutoProxyRegistrar;
025import org.springframework.util.ClassUtils;
026import org.springframework.util.StringUtils;
027
028/**
029 * Selects which implementation of {@link AbstractCachingConfiguration} should
030 * be used based on the value of {@link EnableCaching#mode} on the importing
031 * {@code @Configuration} class.
032 *
033 * <p>Detects the presence of JSR-107 and enables JCache support accordingly.
034 *
035 * @author Chris Beams
036 * @author Stephane Nicoll
037 * @since 3.1
038 * @see EnableCaching
039 * @see ProxyCachingConfiguration
040 */
041public class CachingConfigurationSelector extends AdviceModeImportSelector<EnableCaching> {
042
043        private static final String PROXY_JCACHE_CONFIGURATION_CLASS =
044                        "org.springframework.cache.jcache.config.ProxyJCacheConfiguration";
045
046        private static final String CACHE_ASPECT_CONFIGURATION_CLASS_NAME =
047                        "org.springframework.cache.aspectj.AspectJCachingConfiguration";
048
049        private static final String JCACHE_ASPECT_CONFIGURATION_CLASS_NAME =
050                        "org.springframework.cache.aspectj.AspectJJCacheConfiguration";
051
052
053        private static final boolean jsr107Present;
054
055        private static final boolean jcacheImplPresent;
056
057        static {
058                ClassLoader classLoader = CachingConfigurationSelector.class.getClassLoader();
059                jsr107Present = ClassUtils.isPresent("javax.cache.Cache", classLoader);
060                jcacheImplPresent = ClassUtils.isPresent(PROXY_JCACHE_CONFIGURATION_CLASS, classLoader);
061        }
062
063
064        /**
065         * Returns {@link ProxyCachingConfiguration} or {@code AspectJCachingConfiguration}
066         * for {@code PROXY} and {@code ASPECTJ} values of {@link EnableCaching#mode()},
067         * respectively. Potentially includes corresponding JCache configuration as well.
068         */
069        @Override
070        public String[] selectImports(AdviceMode adviceMode) {
071                switch (adviceMode) {
072                        case PROXY:
073                                return getProxyImports();
074                        case ASPECTJ:
075                                return getAspectJImports();
076                        default:
077                                return null;
078                }
079        }
080
081        /**
082         * Return the imports to use if the {@link AdviceMode} is set to {@link AdviceMode#PROXY}.
083         * <p>Take care of adding the necessary JSR-107 import if it is available.
084         */
085        private String[] getProxyImports() {
086                List<String> result = new ArrayList<>(3);
087                result.add(AutoProxyRegistrar.class.getName());
088                result.add(ProxyCachingConfiguration.class.getName());
089                if (jsr107Present && jcacheImplPresent) {
090                        result.add(PROXY_JCACHE_CONFIGURATION_CLASS);
091                }
092                return StringUtils.toStringArray(result);
093        }
094
095        /**
096         * Return the imports to use if the {@link AdviceMode} is set to {@link AdviceMode#ASPECTJ}.
097         * <p>Take care of adding the necessary JSR-107 import if it is available.
098         */
099        private String[] getAspectJImports() {
100                List<String> result = new ArrayList<>(2);
101                result.add(CACHE_ASPECT_CONFIGURATION_CLASS_NAME);
102                if (jsr107Present && jcacheImplPresent) {
103                        result.add(JCACHE_ASPECT_CONFIGURATION_CLASS_NAME);
104                }
105                return StringUtils.toStringArray(result);
106        }
107
108}