/*
* Copyright 2002-2020 the original author or authors.
*
* Licensed 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
*
* https://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.springframework.core.convert.support;
import org.springframework.core.convert.converter.Converter;
import org.springframework.core.convert.converter.ConverterFactory;
import org.springframework.lang.Nullable;
Converts from a String to a Enum
by calling Enum.valueOf(Class<Z#0-T#1>, String)
. Author: Keith Donald, Stephane Nicoll Since: 3.0
/**
* Converts from a String to a {@link java.lang.Enum} by calling {@link Enum#valueOf(Class, String)}.
*
* @author Keith Donald
* @author Stephane Nicoll
* @since 3.0
*/
@SuppressWarnings({"rawtypes", "unchecked"})
final class StringToEnumConverterFactory implements ConverterFactory<String, Enum> {
@Override
public <T extends Enum> Converter<String, T> getConverter(Class<T> targetType) {
return new StringToEnum(ConversionUtils.getEnumType(targetType));
}
private static class StringToEnum<T extends Enum> implements Converter<String, T> {
private final Class<T> enumType;
StringToEnum(Class<T> enumType) {
this.enumType = enumType;
}
@Override
@Nullable
public T convert(String source) {
if (source.isEmpty()) {
// It's an empty enum identifier: reset the enum value to null.
return null;
}
return (T) Enum.valueOf(this.enumType, source.trim());
}
}
}