    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
    015package org.apache.tapestry5.http.internal.services;
    016
    017import org.apache.tapestry5.http.annotations.ImmutableSessionPersistedObject;
    018import org.apache.tapestry5.http.services.SessionPersistedObjectAnalyzer;
    019
    020/**
    021 * Default catch-all implementation of {@link org.apache.tapestry5.http.services.SessionPersistedObjectAnalyzer}.
    022 *
    023 * @since 5.1.0.0
    024 */
    025public class DefaultSessionPersistedObjectAnalyzer implements SessionPersistedObjectAnalyzer<Object>
    026{
    027    /**
    028     * An object is dirty <em>unless</em> it has the {@link org.apache.tapestry5.http.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}