easyPoi根据字段输入多sheet动态导出

最近在做根据前端选择导出字段，然后根据选择的字段，动态的导出对应信息。

    /**
     * 多sheet导出
     * @param title 标题
     * @param secTitle 副标题
     * @param sheetName sheet名称
     * @param data 数据list
     * @param fields 导出字段集合
     * @param clazz 导出对象class
     * @return
     * @throws Exception
     */
public static byte[] exportMultiSheetExcel(Object title,Object secTitle,String sheetName,  List<?> data, List<String> fields, Class<?> clazz) throws Exception{
        byte[] content = null;
        // 把查询到的数据按设置的sheet的容量进行切割
        List<List<?>> lists = SplitList.splitList(data, PAGE_SIZE);
        //List<ExcelExportEntity> entityList = dynamicExportFields(clazz,fields);
        List<ExcelExportEntity> entityList = dynamicComplexFields(clazz,fields);
        @Cleanup
        ByteArrayOutputStream bos  = new ByteArrayOutputStream();
        String firstTitle  = ObjectUtil.isEmpty(title) ? null : title.toString();
        String secondTitle = ObjectUtil.isEmpty(secTitle) ? null : secTitle.toString();
        try{
            Workbook workbook = new XSSFWorkbook();
            // 遍历sheet
            for (int i = 1; i <= lists.size(); ++i) {
                String sheetNamed = sheetName+i;
                ExcelExportService server = new ExcelExportService();
                ExportParams exportParams = new ExportParams(firstTitle, sheetNamed,         ExcelType.XSSF);
                exportParams.setSecondTitle(secondTitle);
                // excel样式
                exportParams.setStyle(ExcelExportTitleStyle.class);
                //server.createSheetForMap(workbook, exportParams,     entityList,objectToMap(lists.get(i)));
                server.createSheetForMap(workbook, exportParams, entityList,lists.get(i-1));
            }
            workbook.write(bos);
            workbook.close();
            content = bos.toByteArray();
/*// 文件落地，用来测试文件的格式和数据的完整性
                @Cleanup InputStream is = new ByteArrayInputStream(content);
                @Cleanup FileOutputStream fileOutputStream = new     FileOutputStream("d:/data/hahaha.xlsx");
                @Cleanup BufferedInputStream bis = new BufferedInputStream(is);
                @Cleanup BufferedOutputStream bos1 = new BufferedOutputStream(fileOutputStream);
                byte[] buff = new byte[2048];
                int bytesRead;
                while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
                    bos1.write(buff, 0, bytesRead);
                 }
                log.info("文件落地磁盘");*/
        }catch (Exception e){
            log.error("导出失败-----------------------------------",e);
            throw new Exception("导出失败！");
        }
        return content;
    }

private static List<ExcelExportEntity> dynamicComplexFields(Class<?> clazz, List<String> fields) {
        List<ExcelExportEntity> beanList = new ArrayList<>();
        try {
            for (String field:fields) {
                Field f = clazz.getDeclaredField(field);
                f.setAccessible(true);
                ExcelExportEntity entity = dynamicFields(f,clazz);
                if(ObjectUtil.isEmpty(entity)){
                    continue;
                }else{
                    beanList.add(entity);
                }
            }
        }catch (NoSuchFieldException e){
            e.printStackTrace();
        }
        return beanList;
    }

    private static ExcelExportEntity dynamicFields(Field f,Class<?> clazz){
        ExcelExportEntity entity = null;
        if(f.isAnnotationPresent(Excel.class)){
            entity = dynamicSingleFields(f,clazz);
        }else if(f.isAnnotationPresent(ExcelCollection.class)){
            entity = dynamicCollFields(f,clazz);
        }
        return entity;
    }

    private static ExcelExportEntity dynamicSingleFields(Field f,Class<?> clazz) {
        ExcelExportEntity entity = new ExcelExportEntity();
        f.setAccessible(true);
        Excel annotation = f.getAnnotation((Excel.class));
        String comment = annotation.name();
        Double width = annotation.width();
        entity.setKey(f.getName());
        entity.setWidth(width.intValue());
        entity.setHeight(annotation.height());
        entity.setName(comment);
        entity.setType(annotation.type());
        entity.setMethod(PoiReflectorUtil.fromCache(clazz).getGetMethod(f.getName()));
        entity.setExportImageType(annotation.imageType());
        entity.setNeedMerge(annotation.needMerge());
        entity.setMergeVertical(annotation.mergeVertical());
        entity.setMergeRely(annotation.mergeRely());
        entity.setFormat(annotation.format());
        entity.setOrderNum(Integer.parseInt(annotation.orderNum()));
        return entity;
    }

    private  static ExcelExportEntity dynamicCollFields(Field field,Class<?> clazz) {
        ExcelExportEntity entity = new ExcelExportEntity();
        field.setAccessible(true);
        ExcelCollection annotation = field.getAnnotation((ExcelCollection.class));
        String comment = annotation.name();
        entity.setKey(field.getName());
        entity.setName(comment);
        entity.setOrderNum(Integer.parseInt(annotation.orderNum()));
        entity.setMethod(PoiReflectorUtil.fromCache(clazz).getGetMethod(field.getName()));
        Type genericType = field.getGenericType();
        ParameterizedType pt = (ParameterizedType) genericType;
        Class<?> aClass = (Class<?>)pt.getActualTypeArguments()[0];
        Field[] fields = aClass.getDeclaredFields();
        List<ExcelExportEntity> list = new ArrayList<>();
        for (Field f:fields) {
            f.setAccessible(true);
            ExcelExportEntity entity1 = dynamicFields(f,aClass);
            list.add(entity1);
        }
        entity.setList(list);
        return entity;
    }

数据分页工具：

/**
 * 数据拆分分页
 *
 * @Author EDZ
 * @Date 2022/9/22
 */

public class SplitList {
    /**
     * 切割查询的数据
     * @param list 需要切割的数据
     * @param len 按照什么长度切割
     * @param <T>
     * @return
     */
    public static  List<List<?>> splitList(List<?> list, int len) {
        if (list == null || list.size() == 0 || len < 1) {
            return null;
        }
        List<List<?>> result = new ArrayList<List<?>>();
        int size = list.size();
        int count = (size + len - 1) / len;
        for (int i = 0; i < count; i++) {
            List<?> subList = list.subList(i * len, (Math.min((i + 1) * len, size)));
            result.add(subList);
        }
        return result;
    }

    /**
     * 集合平均分组
     * @param source 源集合
     * @param n 分成n个集合
     * @param <T> 集合类型
     * @return 平均分组后的集合
     */
    public static <T> List<List<T>> groupList(List<T> source, int n) {
        if (source == null || source.size() == 0 || n < 1) {
            return null;
        }
        if (source.size() < n) {
            return Collections.singletonList(source);
        }
        List<List<T>> result = new ArrayList<List<T>>();
        int number = source.size() / n;
        int remaider = source.size() % n;
        // 偏移量，每有一个余数分配，就要往右偏移一位
        int offset = 0;
        for (int i = 0; i < n;i++) {
            List<T> list1 = null;
            if (remaider > 0){
                list1 = source.subList(i * number + offset,(i + 1) * number + offset + 1);
                remaider--;
                offset++;
            }else {
                list1 = source.subList(i * number + offset, (i+1) * number + offset);
            }
            result.add(list1);
        }
        return result;
    }
}

设置样式的类ExcelExportTitleStyle

import cn.afterturn.easypoi.excel.export.styler.AbstractExcelExportStyler;
import cn.afterturn.easypoi.excel.export.styler.IExcelExportStyler;
import org.apache.poi.ss.usermodel.*;

/**
 * 样式
 *
 * @Author 
 * @Date 2022/10/10
 */

public class ExcelExportTitleStyle extends AbstractExcelExportStyler implements IExcelExportStyler {

    public ExcelExportTitleStyle(Workbook workbook) {
        super.createStyles(workbook);
    }

    @Override
    public CellStyle getTitleStyle(short color) {
        CellStyle titleStyle = workbook.createCellStyle();
        // 自定义字体
        Font font = workbook.createFont();
        font.setColor(IndexedColors.WHITE1.getIndex());
        font.setBold(true);
        font.setFontName("宋体");
        titleStyle.setFont(font);

        // 自定义背景色
        titleStyle.setFillForegroundColor(IndexedColors.GREY_25_PERCENT.getIndex());
        titleStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);

        titleStyle.setBorderBottom(BorderStyle.THIN);
        titleStyle.setBorderTop(BorderStyle.THIN);
        titleStyle.setBorderLeft(BorderStyle.THIN);
        titleStyle.setBorderRight(BorderStyle.THIN);

        titleStyle.setAlignment(HorizontalAlignment.CENTER);
        titleStyle.setVerticalAlignment(VerticalAlignment.CENTER);
        titleStyle.setWrapText(true);
        return titleStyle;
    }

    @Override
    public CellStyle stringSeptailStyle(Workbook workbook, boolean isWarp) {
        CellStyle style = workbook.createCellStyle();
        style.setAlignment(HorizontalAlignment.CENTER);
        style.setVerticalAlignment(VerticalAlignment.CENTER);
        style.setDataFormat(STRING_FORMAT);
        if (isWarp) {
            style.setWrapText(true);
        }
        return style;
    }

    @Override
    public CellStyle getHeaderStyle(short color) {
        CellStyle titleStyle = workbook.createCellStyle();
        Font font = workbook.createFont();
        font.setFontHeightInPoints((short) 12);
        font.setBold(true);
        titleStyle.setFont(font);
        titleStyle.setAlignment(HorizontalAlignment.CENTER);
        titleStyle.setVerticalAlignment(VerticalAlignment.CENTER);
        return titleStyle;
    }

    @Override
    public CellStyle stringNoneStyle(Workbook workbook, boolean isWarp) {
        CellStyle style = workbook.createCellStyle();
        style.setAlignment(HorizontalAlignment.CENTER);
        style.setVerticalAlignment(VerticalAlignment.CENTER);
        style.setDataFormat(STRING_FORMAT);
        if (isWarp) {
            style.setWrapText(true);
        }
        return style;
    }
}