001/*
002 *  Copyright (c) 2022-2023, Mybatis-Flex (fuhai999@gmail.com).
003 *  <p>
004 *  Licensed under the Apache License, Version 2.0 (the "License");
005 *  you may not use this file except in compliance with the License.
006 *  You may obtain a copy of the License at
007 *  <p>
008 *  http://www.apache.org/licenses/LICENSE-2.0
009 *  <p>
010 *  Unless required by applicable law or agreed to in writing, software
011 *  distributed under the License is distributed on an "AS IS" BASIS,
012 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 *  See the License for the specific language governing permissions and
014 *  limitations under the License.
015 */
016package com.mybatisflex.core.util;
017
018import com.mybatisflex.annotation.EnumValue;
019import com.mybatisflex.core.exception.FlexExceptions;
020
021import java.lang.reflect.Field;
022import java.lang.reflect.Method;
023import java.lang.reflect.Modifier;
024import java.util.Map;
025import java.util.concurrent.ConcurrentHashMap;
026
027public class EnumWrapper<E extends Enum<E>> {
028
029    private static final Map<Class, EnumWrapper> cache = new ConcurrentHashMap<>();
030
031    private boolean hasEnumValueAnnotation = false;
032
033    private Class<?> enumClass;
034    private E[] enums;
035    private Field property;
036    private Class<?> propertyType;
037    private Method getterMethod;
038
039    public static <R extends Enum<R>> EnumWrapper<R> of(Class<?> enumClass) {
040        return MapUtil.computeIfAbsent(cache, enumClass, EnumWrapper::new);
041    }
042
043    public EnumWrapper(Class<E> enumClass) {
044        this.enumClass = enumClass;
045        this.enums = enumClass.getEnumConstants();
046
047        Field enumValueField = ClassUtil.getFirstField(enumClass, field -> field.getAnnotation(EnumValue.class) != null);
048        if (enumValueField != null) {
049            hasEnumValueAnnotation = true;
050        }
051
052        if (hasEnumValueAnnotation) {
053            String getterMethodName = "get" + StringUtil.firstCharToUpperCase(enumValueField.getName());
054
055            Method getter = ClassUtil.getFirstMethod(enumClass, method -> {
056                String methodName = method.getName();
057                return methodName.equals(getterMethodName) && Modifier.isPublic(method.getModifiers());
058            });
059
060            propertyType = ClassUtil.getWrapType(enumValueField.getType());
061
062            if (getter == null) {
063                if (Modifier.isPublic(enumValueField.getModifiers())) {
064                    property = enumValueField;
065                } else {
066                    throw new IllegalStateException("Can not find method \"" + getterMethodName + "()\" in enum: " + enumClass.getName());
067                }
068            } else {
069                this.getterMethod = getter;
070            }
071        }
072
073        if (!hasEnumValueAnnotation) {
074            Method enumValueMethod = ClassUtil.getFirstMethod(enumClass, method -> method.getAnnotation(EnumValue.class) != null);
075            if (enumValueMethod != null) {
076                String methodName = enumValueMethod.getName();
077                if (!(methodName.startsWith("get") && methodName.length() > 3)) {
078                    throw new IllegalStateException("Can not find get method \"" + methodName + "()\" in enum: " + enumClass.getName());
079                }
080                this.getterMethod = enumValueMethod;
081                this.hasEnumValueAnnotation = true;
082                Class<?> returnType = enumValueMethod.getReturnType();
083                if (returnType.isPrimitive()) {
084                    returnType = ConvertUtil.primitiveToBoxed(returnType);
085                }
086                this.propertyType = returnType;
087            }
088        }
089    }
090
091    /**
092     * 获取枚举值
093     * 顺序：
094     * 1、@EnumValue标识的get方法
095     * 2、@EnumValue标识的属性
096     * 3、没有使用@EnumValue，取枚举name
097     *
098     * @param object
099     * @return
100     */
101    public Object getEnumValue(E object) {
102        try {
103            if (getterMethod != null) {
104                return getterMethod.invoke(object);
105            } else if(property != null){
106                return property.get(object);
107            } else {
108                return object.name();
109            }
110        } catch (Exception e) {
111            throw FlexExceptions.wrap(e);
112        }
113    }
114
115
116    public E getEnum(Object value) {
117        if (value != null) {
118            for (E e : enums) {
119                if (value.equals(getEnumValue(e))) {
120                    return e;
121                }
122            }
123        }
124        return null;
125    }
126
127
128    public boolean hasEnumValueAnnotation() {
129        return hasEnumValueAnnotation;
130    }
131
132    public Class<?> getEnumClass() {
133        return enumClass;
134    }
135
136    public E[] getEnums() {
137        return enums;
138    }
139
140    public Field getProperty() {
141        return property;
142    }
143
144    public Class<?> getPropertyType() {
145        return propertyType;
146    }
147
148    public Method getGetterMethod() {
149        return getterMethod;
150    }
151
152}