/*
* Copyright 2012-2017 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.boot.context.properties.bind.convert;
import java.util.EnumSet;
import java.util.Set;
import org.springframework.core.convert.converter.Converter;
import org.springframework.core.convert.converter.ConverterFactory;
import org.springframework.util.Assert;
/**
* Converts from a String to a {@link java.lang.Enum} by calling searching matching enum
* names (ignoring case).
*
* @author Phillip Webb
*/
@SuppressWarnings({ "unchecked", "rawtypes" })
class StringToEnumConverterFactory implements ConverterFactory<String, Enum> {
@Override
public <T extends Enum> Converter<String, T> getConverter(Class<T> targetType) {
Class<?> enumType = targetType;
while (enumType != null && !enumType.isEnum()) {
enumType = enumType.getSuperclass();
}
Assert.notNull(enumType,
"The target type " + targetType.getName() + " does not refer to an enum");
return new StringToEnum(enumType);
}
private class StringToEnum<T extends Enum> implements Converter<String, T> {
private final Class<T> enumType;
StringToEnum(Class<T> enumType) {
this.enumType = enumType;
}
@Override
public T convert(String source) {
if (source.isEmpty()) {
return null;
}
source = source.trim();
try {
return (T) Enum.valueOf(this.enumType, source);
}
catch (Exception ex) {
return findEnum(source);
}
}
private T findEnum(String source) {
String name = getLettersAndDigits(source);
for (T candidate : (Set<T>) EnumSet.allOf(this.enumType)) {
if (getLettersAndDigits(candidate.name()).equals(name)) {
return candidate;
}
}
throw new IllegalArgumentException("No enum constant "
+ this.enumType.getCanonicalName() + "." + source);
}
private String getLettersAndDigits(String name) {
StringBuilder canonicalName = new StringBuilder(name.length());
name.chars().map((c) -> (char) c).filter(Character::isLetterOrDigit)
.map(Character::toLowerCase).forEach(canonicalName::append);
return canonicalName.toString();
}
}
}