001/* 002 * Copyright 2002-2015 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.Collection; 020 021import org.springframework.beans.factory.annotation.Autowired; 022import org.springframework.cache.CacheManager; 023import org.springframework.cache.interceptor.CacheErrorHandler; 024import org.springframework.cache.interceptor.CacheResolver; 025import org.springframework.cache.interceptor.KeyGenerator; 026import org.springframework.context.annotation.Configuration; 027import org.springframework.context.annotation.ImportAware; 028import org.springframework.core.annotation.AnnotationAttributes; 029import org.springframework.core.type.AnnotationMetadata; 030import org.springframework.util.CollectionUtils; 031 032/** 033 * Abstract base {@code @Configuration} class providing common structure 034 * for enabling Spring's annotation-driven cache management capability. 035 * 036 * @author Chris Beams 037 * @author Stephane Nicoll 038 * @since 3.1 039 * @see EnableCaching 040 */ 041@Configuration 042public abstract class AbstractCachingConfiguration implements ImportAware { 043 044 protected AnnotationAttributes enableCaching; 045 046 protected CacheManager cacheManager; 047 048 protected CacheResolver cacheResolver; 049 050 protected KeyGenerator keyGenerator; 051 052 protected CacheErrorHandler errorHandler; 053 054 055 @Override 056 public void setImportMetadata(AnnotationMetadata importMetadata) { 057 this.enableCaching = AnnotationAttributes.fromMap( 058 importMetadata.getAnnotationAttributes(EnableCaching.class.getName(), false)); 059 if (this.enableCaching == null) { 060 throw new IllegalArgumentException( 061 "@EnableCaching is not present on importing class " + importMetadata.getClassName()); 062 } 063 } 064 065 @Autowired(required = false) 066 void setConfigurers(Collection<CachingConfigurer> configurers) { 067 if (CollectionUtils.isEmpty(configurers)) { 068 return; 069 } 070 if (configurers.size() > 1) { 071 throw new IllegalStateException(configurers.size() + " implementations of " + 072 "CachingConfigurer were found when only 1 was expected. " + 073 "Refactor the configuration such that CachingConfigurer is " + 074 "implemented only once or not at all."); 075 } 076 CachingConfigurer configurer = configurers.iterator().next(); 077 useCachingConfigurer(configurer); 078 } 079 080 /** 081 * Extract the configuration from the nominated {@link CachingConfigurer}. 082 */ 083 protected void useCachingConfigurer(CachingConfigurer config) { 084 this.cacheManager = config.cacheManager(); 085 this.cacheResolver = config.cacheResolver(); 086 this.keyGenerator = config.keyGenerator(); 087 this.errorHandler = config.errorHandler(); 088 } 089 090}