org.jnap.core.bean.converter.PersistentEnumConverterFactory.java Source code

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Here is the source code for org.jnap.core.bean.converter.PersistentEnumConverterFactory.java

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/*
 * PersistentEnumConverterFactory.java created on 2011-06-14
 *
 * Created by Brushing Bits Labs
 * http://www.brushingbits.org
 *
 * 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.jnap.core.bean.converter;

import org.jnap.core.bean.model.PersistentEnum;
import org.jnap.core.bean.model.PersistentEnumFactory;
import org.springframework.core.convert.converter.Converter;
import org.springframework.core.convert.converter.ConverterFactory;

/**
 * @author Daniel Rochetti
 *
 */
public class PersistentEnumConverterFactory implements ConverterFactory<String, Enum> {

    @Override
    public <T extends Enum> Converter<String, T> getConverter(Class<T> targetType) {
        return targetType.isAssignableFrom(PersistentEnum.class)
                ? (Converter<String, T>) new StringToPersistentEnum((Class<? extends Enum>) targetType)
                : new StringToEnum<T>(targetType);
    }

    private static class StringToPersistentEnum<T extends Enum> implements Converter<String, T> {

        private final Class<T> enumType;

        StringToPersistentEnum(Class<T> enumType) {
            super();
            this.enumType = enumType;
        }

        @Override
        public T convert(String source) {
            return (T) PersistentEnumFactory.get(source, enumType);
        }

    }

    private class StringToEnum<T extends Enum> implements Converter<String, T> {

        private final Class<T> enumType;

        StringToEnum(Class<T> enumType) {
            this.enumType = enumType;
        }

        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());
        }
    }

}