1.list分割工具

public class ListSplitUtil {
    /**
     * list 分割
     * @param list 待切割list
     * @param length 切割长度
     */
    public static <T> List<List<T>> spiltList (List<T> list, int length){
        int size = list.size();
        // 切割数量
        int count = (size + length - 1) / length;
        List<List<T>> resultList = new ArrayList<>(count);
        for(int i = 0; i < count; i++){
            // 开始位置
            int fromIndex = i * length;
            // 结束位置
            int toIndex = Math.min((i + 1) * length, size);
            resultList.add(list.subList(fromIndex, toIndex));
        }
        return resultList;
    }
}

2.mybatis 使用in查询

 public List<ProjectSetionVO> getProjectAddSection(List<String> sectionIdList) {
        LambdaQueryWrapper<TpOpenSection> wrapper= new LambdaQueryWrapper<TpOpenSection>();
        //mybastis 使用in条件式，list长度大于1000时分割，多个list
        if(sectionIdList.size()<=1000){
            wrapper.in(TpOpenSection::getSectionId,sectionIdList);
        } else{
            List<List<String>> lists= ListSplitUtil.spiltList(sectionIdList,1000);
            wrapper.and(item->{
                item.in(TpOpenSection::getSectionId, lists.remove(0));
                for(List<String> objList : lists){
                    item.or().in(TpOpenSection::getSectionId, objList);
                }
            });
        }
        
        List<TpOpenSection> list=super.list(wrapper);
        List<ProjectSetionVO> resultList=list.stream().map(a -> new ProjectSetionVO(a.getSectionId(),a.getSectionCode(),a.getSectionName())  ).collect(Collectors.toList());
        return resultList;
    }