org.springframework.core.convert.support.StringToEnumConverterFactory Maven / Gradle / Ivy
/*
* Copyright 2002-2014 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
*
* 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.springframework.core.convert.support;
import org.springframework.core.convert.converter.Converter;
import org.springframework.core.convert.converter.ConverterFactory;
/**
* Converts from a String to a {@link java.lang.Enum} by calling {@link Enum#valueOf(Class, String)}.
*
* @author Keith Donald
* @since 3.0
*/
@SuppressWarnings({"unchecked", "rawtypes"})
final class StringToEnumConverterFactory implements ConverterFactory {
@Override
public Converter getConverter(Class targetType) {
Class enumType = targetType;
while (enumType != null && !enumType.isEnum()) {
enumType = enumType.getSuperclass();
}
if (enumType == null) {
throw new IllegalArgumentException(
"The target type " + targetType.getName() + " does not refer to an enum");
}
return new StringToEnum(enumType);
}
private class StringToEnum implements Converter {
private final Class enumType;
public StringToEnum(Class enumType) {
this.enumType = enumType;
}
@Override
public T convert(String source) {
if (source.length() == 0) {
// It's an empty enum identifier: reset the enum value to null.
return null;
}
return (T) Enum.valueOf(this.enumType, source.trim());
}
}
}