com.sunchenbin.store.feilong.core.lang.EnumUtil.java Source code

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Here is the source code for com.sunchenbin.store.feilong.core.lang.EnumUtil.java

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/*
 * Copyright (C) 2008 feilong
 *
 * 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 com.sunchenbin.store.feilong.core.lang;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.sunchenbin.store.feilong.core.bean.BeanUtilException;
import com.sunchenbin.store.feilong.core.bean.PropertyUtil;
import com.sunchenbin.store.feilong.core.net.HttpMethodType;
import com.sunchenbin.store.feilong.core.tools.jsonlib.JsonUtil;
import com.sunchenbin.store.feilong.core.tools.slf4j.Slf4jUtil;
import com.sunchenbin.store.feilong.core.util.Validator;

/**
 * {@link java.lang.Enum} .
 * 
 * @author feilong
 * @version 1.0.6 201458 ?3:30:51
 * @version 1.0.8 2014-7-22 13:43 add {@link EnumUtil#getEnumByPropertyValueIgnoreCase(Class, String, Object)}
 * @see org.apache.commons.lang3.EnumUtils
 * @since 1.0.6
 */
public final class EnumUtil {

    /** The Constant LOGGER. */
    private static final Logger LOGGER = LoggerFactory.getLogger(EnumUtil.class);

    /** Don't let anyone instantiate this class. */
    private EnumUtil() {
        //AssertionError?. ?????. ???.
        //see Effective Java 2nd
        throw new AssertionError("No " + getClass().getName() + " instances for you!");
    }

    /**
     * fieldName value(?) (equalsIgnoreCase)<br>
     * 
     * <pre>
     * 
     * ?{@link HttpMethodType} ,?:
     * 
     * {@code
     *  EnumUtil.getEnumByField(HttpMethodType.class, "method", "get")
     * }
     * </pre>
     *
     * @param <E>
     *            the element type
     * @param <T>
     *            the generic type
     * @param enumClass
     *            the enum class  {@link HttpMethodType}
     * @param propertyName
     *            ??, {@link HttpMethodType}method,javabean 
     * @param specifiedValue
     *             post
     * @return  enum constant
     */
    public static <E extends Enum<?>, T> E getEnumByPropertyValueIgnoreCase(Class<E> enumClass, String propertyName,
            T specifiedValue) {
        boolean ignoreCase = true;
        return getEnumByPropertyValue(enumClass, propertyName, specifiedValue, ignoreCase);
    }

    /**
     * fieldName value (equals)<br>
     * 
     * <pre>
     * 
     * ?{@link HttpMethodType} ,?:
     * 
     * {@code
     *  EnumUtil.getEnumByField(HttpMethodType.class, "method", "get")
     * }
     * </pre>
     *
     * @param <E>
     *            the element type
     * @param <T>
     *            the generic type
     * @param enumClass
     *            the enum class  {@link HttpMethodType}
     * @param propertyName
     *            ??, {@link HttpMethodType}method,javabean 
     * @param specifiedValue
     *             post
     * @return  enum constant
     * @since 1.0.8
     */
    public static <E extends Enum<?>, T> E getEnumByPropertyValue(Class<E> enumClass, String propertyName,
            T specifiedValue) {
        boolean ignoreCase = false;
        return getEnumByPropertyValue(enumClass, propertyName, specifiedValue, ignoreCase);
    }

    /**
     * fieldName value .
     * 
     * <pre>
     * 
     * ?{@link HttpMethodType} ,?:
     * 
     * {@code
     *  EnumUtil.getEnumByField(HttpMethodType.class, "method", "get")
     * }
     * </pre>
     *
     * @param <E>
     *            the element type
     * @param <T>
     *            the generic type
     * @param enumClass
     *            the enum class  {@link HttpMethodType}
     * @param propertyName
     *            ??, {@link HttpMethodType}method,javabean 
     * @param specifiedValue
     *             post
     * @param ignoreCase
     *            ??
     * @return  enum constant
     * @see com.sunchenbin.store.feilong.core.bean.BeanUtil#getProperty(Object, String)
     * @since 1.0.8
     */
    private static <E extends Enum<?>, T> E getEnumByPropertyValue(Class<E> enumClass, String propertyName,
            T specifiedValue, boolean ignoreCase) {

        if (Validator.isNullOrEmpty(enumClass)) {
            throw new IllegalArgumentException("enumClass is null or empty!");
        }

        if (Validator.isNullOrEmpty(propertyName)) {
            throw new IllegalArgumentException("the fieldName is null or empty!");
        }

        // An enum is a kind of class
        // An annotation is a kind of interface
        //  Class ?, null.
        E[] enumConstants = enumClass.getEnumConstants();

        if (LOGGER.isDebugEnabled()) {
            LOGGER.debug("enumClass:[{}],enumConstants:{}", enumClass.getCanonicalName(),
                    JsonUtil.format(enumConstants));
        }
        for (E e : enumConstants) {
            Object propertyValue = PropertyUtil.getProperty(e, propertyName);
            if (isEquals(propertyValue, specifiedValue, ignoreCase)) {
                return e;
            }
        }
        String messagePattern = "can not found the enum constants,enumClass:[{}],propertyName:[{}],value:[{}],ignoreCase:[{}]";
        throw new BeanUtilException(
                Slf4jUtil.formatMessage(messagePattern, enumClass, propertyName, specifiedValue, ignoreCase));
    }

    /**
     * Checks if is equals.
     *
     * @param <T>
     *            the generic type
     * @param propertyValue
     *            the property value
     * @param specifiedValue
     *            
     * @param ignoreCase
     *            the ignore case
     * @return true, if checked
     * @since 1.4.0
     */
    private static <T> boolean isEquals(Object propertyValue, T specifiedValue, boolean ignoreCase) {
        if (propertyValue == null || specifiedValue == null) {//  
            return propertyValue == specifiedValue;
        } else if (propertyValue == specifiedValue) {
            return true;
        }
        //  propertyValue  specifiedValue,  ?null 
        String propertyValueString = propertyValue.toString();
        String specifiedValueString = specifiedValue.toString();
        return ignoreCase ? StringUtils.equalsIgnoreCase(propertyValueString, specifiedValueString)
                : StringUtils.equals(propertyValueString, specifiedValueString);
    }
}