com.github.houbb.heaven.util.lang.reflect.ClassGenericUtil Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of heaven Show documentation
Collect base useful tools for dev.
The newest version!
/*
 * Copyright (c)  2019. houbinbin Inc.
 * heaven All rights reserved.
 */

package com.github.houbb.heaven.util.lang.reflect;

import com.github.houbb.heaven.util.guava.Guavas;
import com.github.houbb.heaven.util.lang.ObjectUtil;
import com.github.houbb.heaven.util.util.ArrayUtil;
import com.github.houbb.heaven.util.util.CollectionUtil;

import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.*;

/**
 * class 泛型工具类
 * @author binbin.hou
 * date 2019/2/24
 * @since 0.0.3
 */
public final class ClassGenericUtil {

    private ClassGenericUtil(){}

    /**
     * 获取当前类的泛型接口信息
     * @param clazz 类
     * @return 泛型接口信息
     */
    private static List getGenericInterfaces(final Class clazz) {
        Set typeSet = new HashSet<>();

        // 添加当前类的泛型接口信息
        Type[] types = clazz.getGenericInterfaces();
        if(ArrayUtil.isNotEmpty(types)) {
            typeSet.addAll(Guavas.newArrayList(types));
        }

        // 当前类的泛型父类信息
        Type superType = clazz.getGenericSuperclass();
        if(ObjectUtil.isNotNull(superType)
                && superType.getClass().isInterface()) {
            typeSet.add(superType);
        }

        return Guavas.newArrayList(typeSet);
    }


    /**
     * 获取泛型类型
     * @param clazz 数据类型
     * @param interfaceClass 接口对应的 class 信息
     * @param index 泛型的下标志位置
     * @return 对应的泛型类型
     */
    public static Class getGenericClass(final Class clazz,
                                        final Class interfaceClass,
                                        final int index) {
        List typeList = ClassGenericUtil.getGenericInterfaces(clazz);
        for(Type type : typeList) {
            if(type instanceof ParameterizedType
                    && interfaceClass.equals(((ParameterizedType) type).getRawType())
            ) {
                ParameterizedType p = (ParameterizedType)type;
                return (Class) p.getActualTypeArguments()[index];
            }
        }

        return Object.class;
    }

    /**
     * 获取元素的泛型
     * @param list 列表
     * @return 泛型
     * @since 0.1.26
     */
    public static Class getGenericClass(final Collection list){
        if(CollectionUtil.isEmpty(list)) {
            return null;
        }

        for(Object object : list) {
            if(ObjectUtil.isNotNull(object)) {
                return object.getClass();
            }
        }
        return null;
    }

    /**
     * 获取当前类对应的泛型
     * @param clazz 指定类
     * @param index 索引
     * @return 默认返回 {@link Object#getClass()}
     * @since 0.1.102
     */
    public static Class getGenericSupperClass(final Class clazz,
                                              final int index) {
        Class classType = Object.class;

        Type pageVoParserClass = clazz.getGenericSuperclass();
        if (pageVoParserClass instanceof ParameterizedType) {
            Type[] pageVoClassTypes = ((ParameterizedType)pageVoParserClass).getActualTypeArguments();
            classType = (Class) pageVoClassTypes[index];
        }

        return classType;
    }

    /**
     * 获取当前类对应的泛型
     * @param clazz 指定类
     * @return 默认返回 {@link Object#getClass()}
     * @since 0.1.102
     */
    public static Class getGenericSupperClass(final Class clazz) {
        return getGenericSupperClass(clazz, 0);
    }

    /**
     * 获取运行时泛型的类型
     * @param wrapper 包装类
     * @param  泛型
     * @return 类别
     * @since 0.2.5
     */
    public static  Type getGenericRuntimeType(Wrapper wrapper) {
        Type type = wrapper.getClass().getGenericSuperclass();
        if (type == null) {
            return null;
        }

        if (type instanceof ParameterizedType) {
            Type[] types = ((ParameterizedType)type).getActualTypeArguments();
            return types[0];
        }
        return null;
    }

}