org.springframework.cache.Cache Maven / Gradle / Ivy
/*
* Copyright 2002-2013 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;
/**
* Interface that defines the common cache operations.
*
* Note: Due to the generic use of caching, it is recommended that
* implementations allow storage of null values (for example to
* cache methods that return {@code null}).
*
* @author Costin Leau
* @since 3.1
*/
public interface Cache {
/**
* Return the cache name.
*/
String getName();
/**
* Return the the underlying native cache provider.
*/
Object getNativeCache();
/**
* Return the value to which this cache maps the specified key.
* Returns {@code null} if the cache contains no mapping for this key;
* otherwise, the cached value (which may be {@code null} itself) will
* be returned in a {@link ValueWrapper}.
* @param key the key whose associated value is to be returned
* @return the value to which this cache maps the specified key,
* contained within a {@link ValueWrapper} which may also hold
* a cached {@code null} value. A straight {@code null} being
* returned means that the cache contains no mapping for this key.
*/
ValueWrapper get(Object key);
/**
* Associate the specified value with the specified key in this cache.
*
If the cache previously contained a mapping for this key, the old
* value is replaced by the specified value.
* @param key the key with which the specified value is to be associated
* @param value the value to be associated with the specified key
*/
void put(Object key, Object value);
/**
* Evict the mapping for this key from this cache if it is present.
* @param key the key whose mapping is to be removed from the cache
*/
void evict(Object key);
/**
* Remove all mappings from the cache.
*/
void clear();
/**
* A (wrapper) object representing a cache value.
*/
interface ValueWrapper {
/**
* Return the actual value in the cache.
*/
Object get();
}
}