lodsve.web.mvc.convert.EnumCodeConverterFactory Maven / Gradle / Ivy

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/*
 * Copyright (C) 2018  Sun.Hao
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see .
 */

package lodsve.web.mvc.convert;

import lodsve.core.bean.Codeable;
import lodsve.core.utils.StringUtils;
import org.springframework.core.convert.TypeDescriptor;
import org.springframework.core.convert.converter.ConditionalConverter;
import org.springframework.core.convert.converter.Converter;
import org.springframework.core.convert.converter.ConverterFactory;

/**
 * spring mvc将传递的参数转换成枚举.
 *
 * @author sunhao([email protected])
 * @date 2014-12-17 20:23
 */
public class EnumCodeConverterFactory implements ConverterFactory>, ConditionalConverter {
    @Override
    public boolean matches(TypeDescriptor sourceType, TypeDescriptor targetType) {
        Class clazz = targetType.getType();
        return Enum.class.isAssignableFrom(clazz) && Codeable.class.isAssignableFrom(clazz);
    }

    @Override
    @SuppressWarnings("unchecked")
    public > Converter getConverter(Class targetType) {
        if (!Codeable.class.isAssignableFrom(targetType)) {
            return null;
        }

        return new ValueToEnum(targetType);
    }

    private class ValueToEnum & Codeable> implements Converter {
        private T[] enums;
        private Class enumType;

        private ValueToEnum(Class enumType) {
            this.enumType = enumType;
            this.enums = enumType.getEnumConstants();
        }

        @Override
        public T convert(String source) {
            if (StringUtils.isBlank(source)) {
                return null;
            }

            T result;
            try {
                result = Enum.valueOf(enumType, source);
            } catch (Exception e) {
                result = null;
            }

            if (result != null) {
                return result;
            }

            for (T em : enums) {
                if (em.getCode().equals(source)) {
                    result = em;
                    break;
                }
            }

            return result;
        }
    }
}