org.apache.commons.lang.enums.EnumUtils Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.lang.enums;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
/**
* Utility class for accessing and manipulating {@link Enum}s.
*
* @see Enum
* @see ValuedEnum
* @author Apache Software Foundation
* @author Gary Gregory
* @since 2.1 (class existed in enum package from v1.0)
* @version $Id: EnumUtils.java 905636 2010-02-02 14:03:32Z niallp $
*/
public class EnumUtils {
/**
* Public constructor. This class should not normally be instantiated.
* @since 2.0
*/
public EnumUtils() {
super();
}
/**
* Gets an Enum object by class and name.
*
* @param enumClass the class of the Enum to get
* @param name the name of the Enum to get, may be null
* @return the enum object
* @throws IllegalArgumentException if the enum class is null
*/
public static Enum getEnum(Class enumClass, String name) {
return Enum.getEnum(enumClass, name);
}
/**
* Gets a ValuedEnum object by class and value.
*
* @param enumClass the class of the Enum to get
* @param value the value of the Enum to get
* @return the enum object, or null if the enum does not exist
* @throws IllegalArgumentException if the enum class is null
*/
public static ValuedEnum getEnum(Class enumClass, int value) {
return (ValuedEnum) ValuedEnum.getEnum(enumClass, value);
}
/**
* Gets the Map of Enum objects by
* name using the Enum class.
*
* If the requested class has no enum objects an empty
* Map is returned. The Map is unmodifiable.
*
* @param enumClass the class of the Enum to get
* @return the enum object Map
* @throws IllegalArgumentException if the enum class is null
* @throws IllegalArgumentException if the enum class is not a subclass
* of Enum
*/
public static Map getEnumMap(Class enumClass) {
return Enum.getEnumMap(enumClass);
}
/**
* Gets the List of Enum objects using
* the Enum class.
*
* The list is in the order that the objects were created
* (source code order).
*
* If the requested class has no enum objects an empty
* List is returned. The List is unmodifiable.
*
* @param enumClass the class of the Enum to get
* @return the enum object Map
* @throws IllegalArgumentException if the enum class is null
* @throws IllegalArgumentException if the enum class is not a subclass
* of Enum
*/
public static List getEnumList(Class enumClass) {
return Enum.getEnumList(enumClass);
}
/**
* Gets an Iterator over the Enum objects
* in an Enum class.
*
* The iterator is in the order that the objects were created
* (source code order).
*
* If the requested class has no enum objects an empty
* Iterator is returned. The Iterator
* is unmodifiable.
*
* @param enumClass the class of the Enum to get
* @return an Iterator of the Enum objects
* @throws IllegalArgumentException if the enum class is null
* @throws IllegalArgumentException if the enum class is not a subclass of Enum
*/
public static Iterator iterator(Class enumClass) {
return Enum.getEnumList(enumClass).iterator();
}
}