039.制作CopyUtil封装BeanUtils

1.单个对象的复制

EbookResp ebookResp = new EbookResp(); 
BeanUtils.copyProperties(ebook, ebookResp);

2.list对象的复制

List<EbookResp> respList = new ArrayList<>();
        for (Ebook ebook : ebookList) {
        　　EbookResp ebookResp = new EbookResp();
         　　 BeanUtils.copyProperties(ebook, ebookResp);
                EbookResp ebookResp = CopyUtil.copy(ebook, EbookResp.class);
             respList.add(ebookResp);
         }

3.制作制作CopyUtil封装BeanUtils

package com.jiawa.wiki.util;

import org.springframework.beans.BeanUtils;
import org.springframework.util.CollectionUtils;

import java.util.ArrayList;
import java.util.List;

public class CopyUtil {

    /**
     * 单体复制
     */
    public static <T> T copy(Object source, Class<T> clazz) {
        if (source == null) {
            return null;
        }
        T obj = null;
        try {
            obj = clazz.newInstance();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
        BeanUtils.copyProperties(source, obj);
        return obj;
    }

    /**
     * 列表复制
     */
    public static <T> List<T> copyList(List source, Class<T> clazz) {
        List<T> target = new ArrayList<>();
        if (!CollectionUtils.isEmpty(source)){
            for (Object c: source) {
                T obj = copy(c, clazz);
                target.add(obj);
            }
        }
        return target;
    }
}

//利用工具类进行复制

List<EbookResp> list = CopyUtil.copyList(ebookList, EbookResp.class);