001    // Copyright 2005 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.tapestry.engine.state;
016    
017    import org.apache.hivemind.util.Defense;
018    
019    /**
020     * @author Howard M. Lewis Ship
021     * @since 4.0
022     */
023    public class StateObjectManagerImpl implements StateObjectManager
024    {
025        private StateObjectPersistenceManager _persistenceManager;
026    
027        private StateObjectFactory _factory;
028    
029        private String _name;
030    
031        public StateObjectManagerImpl(String name, StateObjectFactory factory,
032                StateObjectPersistenceManager persistenceManager)
033        {
034            Defense.notNull(name, "name");
035            Defense.notNull(factory, "factory");
036            Defense.notNull(persistenceManager, "persistenceManager");
037    
038            _name = name;
039            _factory = factory;
040            _persistenceManager = persistenceManager;
041        }
042    
043        public boolean exists()
044        {
045            return _persistenceManager.exists(_name);
046        }
047    
048        public Object get()
049        {
050            return _persistenceManager.get(_name, _factory);
051        }
052    
053        public void store(Object stateObject)
054        {
055            _persistenceManager.store(_name, stateObject);
056        }
057    }