001    // Copyright 2010 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    // http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry5.internal.transform;
016    
017    /**
018     * Manages a cache value as the result of invoking a no-arguments method.
019     */
020    public interface MethodResultCache
021    {
022        /** Returns true if the cache contains a cached value. May also check to see if the cached value is valid. */
023        boolean isCached();
024    
025        /** Stores a new cached value for later reference. */
026        void set(Object cachedValue);
027    
028        /** Returns the previously cached value, if any. */
029        Object get();
030    
031        /** Resets the cache, discarding the cached value. */
032        void reset();
033    }