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.api.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 * @param <T> The element in the enumeration 033 */ 034public class SingletonEnumeration<T> implements NamingEnumeration<T> 035{ 036 /** The singleton element to return */ 037 private final T element; 038 039 /** Can we return a element */ 040 private boolean hasMore = true; 041 042 043 /** 044 * Creates a NamingEnumeration over a single element. 045 * 046 * @param element 047 * TODO 048 */ 049 public SingletonEnumeration( final T element ) 050 { 051 this.element = element; 052 } 053 054 055 /** 056 * Makes calls to hasMore to false even if we had more. 057 * 058 * @see javax.naming.NamingEnumeration#close() 059 */ 060 public void close() 061 { 062 hasMore = false; 063 } 064 065 066 /** 067 * @see javax.naming.NamingEnumeration#hasMore() 068 */ 069 public boolean hasMore() 070 { 071 return hasMore; 072 } 073 074 075 /** 076 * @see javax.naming.NamingEnumeration#next() 077 */ 078 public T next() 079 { 080 if ( hasMore ) 081 { 082 hasMore = false; 083 return element; 084 } 085 086 throw new NoSuchElementException(); 087 } 088 089 090 /** 091 * @see java.util.Enumeration#hasMoreElements() 092 */ 093 public boolean hasMoreElements() 094 { 095 return hasMore; 096 } 097 098 099 /** 100 * @see java.util.Enumeration#nextElement() 101 */ 102 public T nextElement() 103 { 104 return next(); 105 } 106}