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 */ 020 021 package org.apache.directory.server.dns.util; 022 023 024 import java.util.HashMap; 025 import java.util.Map; 026 027 import org.apache.directory.server.i18n.I18n; 028 029 030 /** 031 * A map to easily get the actual Enum instance from it's value as seen in the 032 * <a href="http://www.javaspecialists.co.za/archive/newsletter.do?issue=113"> 033 * The JavaSpecialists newsletter</a>. 034 * 035 * @param <K> 036 * @param <E> 037 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 038 * @version $Rev$, $Date$ 039 */ 040 public class ReverseEnumMap<K, E extends Enum<E> & EnumConverter<K>> 041 { 042 private Map<K, E> reverseMap = new HashMap<K, E>(); 043 044 045 /** 046 * Creates a new instance of ReverseEnumMap. 047 * 048 * @param enumType 049 */ 050 public ReverseEnumMap( Class<E> enumType ) 051 { 052 for ( E e : enumType.getEnumConstants() ) 053 { 054 reverseMap.put( e.convert(), e ); 055 } 056 } 057 058 059 /** 060 * Return the enum given an ordinal value. 061 * 062 * @param value 063 * @return The enum. 064 */ 065 public E get( K value ) 066 { 067 E e = reverseMap.get( value ); 068 if ( e == null ) 069 { 070 throw new IllegalArgumentException( I18n.err( I18n.ERR_650, value ) ); 071 } 072 return e; 073 } 074 }