    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    }