Java tutorial
/* * 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.bval.jsr.util; import org.apache.commons.beanutils.Converter; /** * A {@code org.apache.commons.beanutils.Converter} implementation to handle * Enumeration type. * * $Id: EnumerationConverter.java 1226560 2012-01-02 22:18:19Z mbenson $ */ public final class EnumerationConverter implements Converter { /** * The static converter instance. */ private static final EnumerationConverter INSTANCE = new EnumerationConverter(); /** * Returns this converter instance. * * @return this converter instance. */ public static EnumerationConverter getInstance() { return INSTANCE; } /** * This class can't be instantiated. */ private EnumerationConverter() { // do nothing } /** * {@inheritDoc} */ @SuppressWarnings({ "unchecked", "rawtypes" }) public Object convert(Class type, Object value) { if (!type.isEnum()) { throw new RuntimeException("Only enum types supported in this version!"); } if (value == null) { throw new RuntimeException("Null values not supported in this version!"); } if (String.class != value.getClass()) { throw new RuntimeException("Only java.lang.String values supported in this version!"); } String stringValue = (String) value; final Class<Enum> enumClass = (Class<Enum>) type; return Enum.valueOf(enumClass, stringValue); } }