001    // Copyright 2004, 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.hivemind.impl;
016    
017    import java.util.AbstractMap;
018    import java.util.Map;
019    import java.util.Set;
020    
021    import org.apache.hivemind.HiveMind;
022    import org.apache.hivemind.events.RegistryShutdownListener;
023    
024    /**
025     * The Map implementation visible to the client code. It defers to another inner implementation of
026     * Map; initially this is a {@link org.apache.hivemind.impl.ElementsInnerProxyMap}, but the inner
027     * proxy replaces itself with a real Map implementation containing the actual configuration
028     * elements.
029     * 
030     * @author Knut Wannheden
031     * @since 1.1
032     */
033    public final class ElementsProxyMap extends AbstractMap implements RegistryShutdownListener
034    {
035        private Map _inner;
036    
037        private boolean _shutdown;
038    
039        public void registryDidShutdown()
040        {
041            _shutdown = true;
042            _inner = null;
043        }
044    
045        private void checkShutdown()
046        {
047            if (_shutdown)
048                throw HiveMind.createRegistryShutdownException();
049        }
050    
051        public Set entrySet()
052        {
053            checkShutdown();
054    
055            return _inner.entrySet();
056        }
057    
058        public String toString()
059        {
060            return _inner.toString();
061        }
062    
063        public boolean equals(Object o)
064        {
065            return _inner.equals(o);
066        }
067    
068        public int hashCode()
069        {
070            return _inner.hashCode();
071        }
072    
073        public void setInner(Map map)
074        {
075            _inner = map;
076        }
077    
078    }