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.AbstractList; 018 import java.util.List; 019 020 import org.apache.hivemind.HiveMind; 021 import org.apache.hivemind.events.RegistryShutdownListener; 022 023 /** 024 * The List implementation visible to the client code. It defers 025 * to another inner implementation of List; initially this is 026 * a {@link org.apache.hivemind.impl.ElementsInnerProxyList}, but the 027 * inner proxy replaces itself with a real List implementation containing 028 * the actual configuration elements. 029 * 030 * @author Howard Lewis Ship 031 */ 032 public final class ElementsProxyList extends AbstractList implements RegistryShutdownListener 033 { 034 private List _inner; 035 private boolean _shutdown; 036 037 public void registryDidShutdown() 038 { 039 _shutdown = true; 040 _inner = null; 041 } 042 043 private void checkShutdown() 044 { 045 if (_shutdown) 046 throw HiveMind.createRegistryShutdownException(); 047 } 048 049 public Object get(int index) 050 { 051 checkShutdown(); 052 053 return _inner.get(index); 054 } 055 056 public int size() 057 { 058 checkShutdown(); 059 060 return _inner.size(); 061 } 062 063 public String toString() 064 { 065 return _inner.toString(); 066 } 067 068 public boolean equals(Object o) 069 { 070 return _inner.equals(o); 071 } 072 073 public int hashCode() 074 { 075 return _inner.hashCode(); 076 } 077 078 public void setInner(List list) 079 { 080 _inner = list; 081 } 082 083 }