org.springframework.cache.jcache.interceptor.AbstractCacheInterceptor Maven / Gradle / Ivy
/*
* Copyright 2002-2018 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.cache.jcache.interceptor;
import java.io.Serializable;
import java.lang.annotation.Annotation;
import java.util.Collection;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.cache.Cache;
import org.springframework.cache.interceptor.AbstractCacheInvoker;
import org.springframework.cache.interceptor.CacheErrorHandler;
import org.springframework.cache.interceptor.CacheOperationInvocationContext;
import org.springframework.cache.interceptor.CacheOperationInvoker;
import org.springframework.lang.Nullable;
import org.springframework.util.CollectionUtils;
/**
* A base interceptor for JSR-107 cache annotations.
*
* @author Stephane Nicoll
* @since 4.1
* @param the operation type
* @param the annotation type
*/
@SuppressWarnings("serial")
abstract class AbstractCacheInterceptor, A extends Annotation>
extends AbstractCacheInvoker implements Serializable {
protected final Log logger = LogFactory.getLog(getClass());
protected AbstractCacheInterceptor(CacheErrorHandler errorHandler) {
super(errorHandler);
}
@Nullable
protected abstract Object invoke(CacheOperationInvocationContext context, CacheOperationInvoker invoker)
throws Throwable;
/**
* Resolve the cache to use.
* @param context the invocation context
* @return the cache to use (never null)
*/
protected Cache resolveCache(CacheOperationInvocationContext context) {
Collection caches = context.getOperation().getCacheResolver().resolveCaches(context);
Cache cache = extractFrom(caches);
if (cache == null) {
throw new IllegalStateException("Cache could not have been resolved for " + context.getOperation());
}
return cache;
}
/**
* Convert the collection of caches in a single expected element.
* Throw an {@link IllegalStateException} if the collection holds more than one element
* @return the single element or {@code null} if the collection is empty
*/
@Nullable
static Cache extractFrom(Collection caches) {
if (CollectionUtils.isEmpty(caches)) {
return null;
}
else if (caches.size() == 1) {
return caches.iterator().next();
}
else {
throw new IllegalStateException("Unsupported cache resolution result " + caches +
": JSR-107 only supports a single cache.");
}
}
}