list和对象数据复制CopyUtil工具类

文章目录

• ​​1. CopyUtil​​
• ​​2. 使用案例​​

1. CopyUtil

package com.gblfy.wiki.util;

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

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

/**
 * @author gblfy
 * @desc list和对象数据复制
 * @date 2021-04-13
 */
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;
    }
}

2. 使用案例

package com.gblfy.wiki.service;

import com.gblfy.wiki.entity.Ebook;
import com.gblfy.wiki.entity.EbookExample;
import com.gblfy.wiki.mapper.EbookMapper;
import com.gblfy.wiki.req.EbookQueryReq;
import com.gblfy.wiki.resp.CommonResp;
import com.gblfy.wiki.resp.EbookQueryResp;
import com.gblfy.wiki.util.CopyUtil;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.util.ObjectUtils;

import java.util.List;

@Service
public class EbookServiceImpl {

    @Autowired
    private EbookMapper ebookMapper;

    public List<EbookQueryResp> list(EbookQueryReq req) {
        EbookExample example = new EbookExample();
        EbookExample.Criteria criteria = example.createCriteria();
        if (!ObjectUtils.isEmpty(req.getName())) {
            criteria.andNameLike("%" + req.getName() + "%");
        }
        List<Ebook> ebookList = ebookMapper.selectByExample(example);
        //集合数据复制 使用案例
        List<EbookQueryResp> list = CopyUtil.copyList(ebookList, EbookQueryResp.class);
        //对象数据复制 使用案例
        Ebook ebook = CopyUtil.copy(req, Ebook.class);
        return list;
    }
}