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}