BeanUtil-Bean转换工具类

1. 对象拷贝

2. List 对象拷贝

3. Map 拷贝

4. json 转 Map

5. 获取对象 空属性

6. bean数组 转 bean数组

import com.alibaba.fastjson.JSON;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.beans.BeanUtils;
import org.springframework.util.CollectionUtils;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.function.Function;

/**
 * @program: xxx
 * @description: Bean 转换工具类
 * @author: 52Hz
 * @create: 2021-10-21 16:31
 **/
public class BeanUtil {


    /**
     * 对象拷贝
     *
     * @param source 源
     * @param target 目标
     */
    public static void copyProperties(Object source, Object target) {
        if (source == null) {
            return;
        }
        BeanUtils.copyProperties(source, target);
    }

    /**
     * List 对象拷贝
     *
     * @param list 源
     * @param <T>  目标
     * @return 目标
     */
    public static <T, E> List copyList(List<T> list, Class<E> clazz) {
        if (CollectionUtils.isEmpty(list)) {
            return new ArrayList();
        }
        return JSON.parseArray(JSON.toJSONString(list), clazz);
    }

    /**
     * MAP拷贝
     *
     * @param map 源
     * @return 目标
     */
    public static Map<String, Object> copyMap(Map map) {
        if (CollectionUtils.isEmpty(map)) {
            return new HashMap<>();
        }
        return JSON.parseObject(JSON.toJSONString(map));
    }

    /**
     * json 转 Map
     *
     * @param json
     * @return
     */
    public static Map<String, Object> jsonToMap(String json) {
        try {
            ObjectMapper objectMapper = new ObjectMapper();
            return objectMapper.readValue(json, Map.class);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return null;
    }
    
    /**
     * 获取对象 空属性
     * 
     * @param source
     * @return
     */
    private static String[] getNullPropertyNames(Object source) {
        BeanWrapper src = new BeanWrapperImpl(source);
        PropertyDescriptor[] pds = src.getPropertyDescriptors();
        Set<String> emptyNames = (Set) Arrays.stream(pds).filter((pd) -> {
            return src.getPropertyValue(pd.getName()) == null;
        }).map(FeatureDescriptor::getName).distinct().collect(Collectors.toSet());
        String[] result = new String[emptyNames.size()];
        return (String[])emptyNames.toArray(result);
    }
    
    /**
     * bean数组 转 bean数组
     *
     * @param source
     * @param function
     * @param <T>
     * @param <R>
     * @return
     */
    public static <T, R> List<R> covert2JavaBeanList(List<T> source, Function<T, R> function) {
        if (null == source || source.size() < 0) {
            return new ArrayList<>();
        }
        List<R> res = new ArrayList<>(source.size());
        for (T t : source) {
            res.add(function.apply(t));
        }
        return res;
    }
}