001: /*
002: * Licensed to the Apache Software Foundation (ASF) under one or more
003: * contributor license agreements. See the NOTICE file distributed with
004: * this work for additional information regarding copyright ownership.
005: * The ASF licenses this file to You under the Apache License, Version 2.0
006: * (the "License"); you may not use this file except in compliance with
007: * the License. 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: package org.apache.commons.lang.enums;
018:
019: import java.util.Iterator;
020: import java.util.List;
021: import java.util.Map;
022:
023: /**
024: * <p>Utility class for accessing and manipulating {@link Enum}s.</p>
025: *
026: * @see Enum
027: * @see ValuedEnum
028: * @author Stephen Colebourne
029: * @author Gary Gregory
030: * @since 2.1 (class existed in enum package from v1.0)
031: * @version $Id: EnumUtils.java 437554 2006-08-28 06:21:41Z bayard $
032: */
033: public class EnumUtils {
034:
035: /**
036: * Public constructor. This class should not normally be instantiated.
037: * @since 2.0
038: */
039: public EnumUtils() {
040: super ();
041: }
042:
043: /**
044: * <p>Gets an <code>Enum</code> object by class and name.</p>
045: *
046: * @param enumClass the class of the <code>Enum</code> to get
047: * @param name the name of the Enum to get, may be <code>null</code>
048: * @return the enum object
049: * @throws IllegalArgumentException if the enum class is <code>null</code>
050: */
051: public static Enum getEnum(Class enumClass, String name) {
052: return Enum.getEnum(enumClass, name);
053: }
054:
055: /**
056: * <p>Gets a <code>ValuedEnum</code> object by class and value.</p>
057: *
058: * @param enumClass the class of the <code>Enum</code> to get
059: * @param value the value of the <code>Enum</code> to get
060: * @return the enum object, or null if the enum does not exist
061: * @throws IllegalArgumentException if the enum class is <code>null</code>
062: */
063: public static ValuedEnum getEnum(Class enumClass, int value) {
064: return (ValuedEnum) ValuedEnum.getEnum(enumClass, value);
065: }
066:
067: /**
068: * <p>Gets the <code>Map</code> of <code>Enum</code> objects by
069: * name using the <code>Enum</code> class.</p>
070: *
071: * <p>If the requested class has no enum objects an empty
072: * <code>Map</code> is returned. The <code>Map</code> is unmodifiable.</p>
073: *
074: * @param enumClass the class of the <code>Enum</code> to get
075: * @return the enum object Map
076: * @throws IllegalArgumentException if the enum class is <code>null</code>
077: * @throws IllegalArgumentException if the enum class is not a subclass
078: * of <code>Enum</code>
079: */
080: public static Map getEnumMap(Class enumClass) {
081: return Enum.getEnumMap(enumClass);
082: }
083:
084: /**
085: * <p>Gets the <code>List</code> of <code>Enum</code> objects using
086: * the <code>Enum</code> class.</p>
087: *
088: * <p>The list is in the order that the objects were created
089: * (source code order).</p>
090: *
091: * <p>If the requested class has no enum objects an empty
092: * <code>List</code> is returned. The <code>List</code> is unmodifiable.</p>
093: *
094: * @param enumClass the class of the Enum to get
095: * @return the enum object Map
096: * @throws IllegalArgumentException if the enum class is <code>null</code>
097: * @throws IllegalArgumentException if the enum class is not a subclass
098: * of <code>Enum</code>
099: */
100: public static List getEnumList(Class enumClass) {
101: return Enum.getEnumList(enumClass);
102: }
103:
104: /**
105: * <p>Gets an <code>Iterator</code> over the <code>Enum</code> objects
106: * in an <code>Enum</code> class.</p>
107: *
108: * <p>The iterator is in the order that the objects were created
109: * (source code order).</p>
110: *
111: * <p>If the requested class has no enum objects an empty
112: * <code>Iterator</code> is returned. The <code>Iterator</code>
113: * is unmodifiable.</p>
114: *
115: * @param enumClass the class of the <code>Enum</code> to get
116: * @return an <code>Iterator</code> of the <code>Enum</code> objects
117: * @throws IllegalArgumentException if the enum class is <code>null</code>
118: * @throws IllegalArgumentException if the enum class is not a subclass of <code>Enum</code>
119: */
120: public static Iterator iterator(Class enumClass) {
121: return Enum.getEnumList(enumClass).iterator();
122: }
123:
124: }
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