001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 * 019 */ 020package org.apache.directory.shared.util; 021 022 023import javax.naming.NamingEnumeration; 024 025import java.util.NoSuchElementException; 026 027 028/** 029 * A NamingEnumeration over a single element. 030 * 031 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 032 */ 033public class SingletonEnumeration<T> implements NamingEnumeration<T> 034{ 035 /** The singleton element to return */ 036 private final T element; 037 038 /** Can we return a element */ 039 private boolean hasMore = true; 040 041 042 /** 043 * Creates a NamingEnumeration over a single element. 044 * 045 * @param element 046 * TODO 047 */ 048 public SingletonEnumeration(final T element) 049 { 050 this.element = element; 051 } 052 053 054 /** 055 * Makes calls to hasMore to false even if we had more. 056 * 057 * @see javax.naming.NamingEnumeration#close() 058 */ 059 public void close() 060 { 061 hasMore = false; 062 } 063 064 065 /** 066 * @see javax.naming.NamingEnumeration#hasMore() 067 */ 068 public boolean hasMore() 069 { 070 return hasMore; 071 } 072 073 074 /** 075 * @see javax.naming.NamingEnumeration#next() 076 */ 077 public T next() 078 { 079 if ( hasMore ) 080 { 081 hasMore = false; 082 return element; 083 } 084 085 throw new NoSuchElementException(); 086 } 087 088 089 /** 090 * @see java.util.Enumeration#hasMoreElements() 091 */ 092 public boolean hasMoreElements() 093 { 094 return hasMore; 095 } 096 097 098 /** 099 * @see java.util.Enumeration#nextElement() 100 */ 101 public T nextElement() 102 { 103 return next(); 104 } 105}