001    // Copyright 2008, 2011 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.services;
016    
017    import org.apache.tapestry5.annotations.ImmutableSessionPersistedObject;
018    import org.apache.tapestry5.services.SessionPersistedObjectAnalyzer;
019    
020    /**
021     * Default catch-all implementation of {@link org.apache.tapestry5.services.SessionPersistedObjectAnalyzer}.
022     *
023     * @since 5.1.0.0
024     */
025    public class DefaultSessionPersistedObjectAnalyzer implements SessionPersistedObjectAnalyzer<Object>
026    {
027        /**
028         * An object is dirty <em>unless</em> it has the {@link org.apache.tapestry5.annotations.ImmutableSessionPersistedObject}
029         * annotation.
030         *
031         * @param sessionPersistedObject to analyze
032         * @return false if immutable, true otherwise
033         */
034        public boolean checkAndResetDirtyState(Object sessionPersistedObject)
035        {
036            boolean immutable = sessionPersistedObject.getClass().getAnnotation(ImmutableSessionPersistedObject.class) != null;
037    
038            // Immutable objects are always clean, others are assumed dirty.
039            // Go implement OptimizedSessionPersistedObject if you don't like it.
040    
041            return !immutable;
042        }
043    }