001 /** 002 * 003 * Copyright 2004 Protique Ltd 004 * 005 * Licensed under the Apache License, Version 2.0 (the "License"); 006 * you may not use this file except in compliance with the License. 007 * You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 * 017 **/ 018 package org.activemq.jndi; 019 020 import javax.naming.NameNotFoundException; 021 import javax.naming.NamingException; 022 023 /** 024 * Allows users to dynamically create items 025 * 026 * @version $Revision: 1.1 $ 027 */ 028 public abstract class LazyCreateContext extends ReadOnlyContext { 029 public Object lookup(String name) throws NamingException { 030 try { 031 return super.lookup(name); 032 } 033 catch (NameNotFoundException e) { 034 Object answer = createEntry(name); 035 if (answer == null) { 036 throw e; 037 } 038 internalBind(name, answer); 039 return answer; 040 } 041 } 042 043 protected abstract Object createEntry(String name); 044 }