1.需求描述

用户要求导出的金额格式为数字，不能导出为文本
在这里插入图片描述

POI导出工具类

import com.platform.park.model.vo.carRecords.ExportOutOfYardVO;
import io.swagger.annotations.ApiModelProperty;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.springframework.cglib.beans.BeanMap;
import org.springframework.stereotype.Service;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.Field;
import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Map;
@Service
public class ExcelExpotUtils {
    public static final int SHEET_PAGE_NUM = 10000;
    public void expoerDataExcel(HttpServletResponse response,String fileName, Class c, List<BeanMap> beanMapList) throws IOException, NoSuchFieldException {
        XSSFWorkbook wb = new XSSFWorkbook();
        // 工作表对象
        XSSFSheet sheet = null;
        //行对象
        Row row = null;
        //列对象
        Cell cell = null;
        List<String> titleList= new ArrayList<>();
        List<String> fieldList = new ArrayList<>();
        Field[] fields = c.getFields();
        for (Field field:fields){
            titleList.add(field.getAnnotation(ApiModelProperty.class).value());
            fieldList.add(field.getName());
        }
        //总行号
        int rowNo = 0;
        //页行号
        int pageRowNo = 0;
        if (beanMapList==null||beanMapList.size()==0){
            sheet = wb.createSheet("工作簿"+(rowNo/SHEET_PAGE_NUM));
            //动态指定当前的工作表
            sheet = wb.getSheetAt(rowNo/SHEET_PAGE_NUM);
            //新建了工作表,重置工作表的行号为0
            pageRowNo = 0;
            // -----------定义表头-----------
            row = sheet.createRow(pageRowNo++);
            // 列数 titleKeyList.size()
            for(int i=0;i<titleList.size();i++){
                Cell cellTem = row.createCell(i);
                cellTem.setCellValue(titleList.get(i));
            }
        }else {
            for (int k = 0; k < beanMapList.size(); k++) {
                Map<String, Object> srcMap = beanMapList.get(k);
                //写入SHEET_PAGE_NUM条后切换到下个工作表
                if (rowNo % SHEET_PAGE_NUM == 0) {
                    //        System.out.println("Current Sheet:" + rowNo/SHEET_PAGE_NUM);
                    //建立新的sheet对象
                    sheet = wb.createSheet("工作簿" + (rowNo / SHEET_PAGE_NUM));
                    //动态指定当前的工作表
                    sheet = wb.getSheetAt(rowNo / SHEET_PAGE_NUM);
                    //新建了工作表,重置工作表的行号为0
                    pageRowNo = 0;
                    // -----------定义表头-----------
                    row = sheet.createRow(pageRowNo++);
                    // 列数 titleKeyList.size()
                    for (int i = 0; i < titleList.size(); i++) {
                        Cell cellTem = row.createCell(i);
                        cellTem.setCellValue(titleList.get(i));
                    }
                    rowNo++;
                    // ---------------------------
                }
                rowNo++;
                //新建行对象
                row = sheet.createRow(pageRowNo++);
                // 行，获取cell值
                for (int j = 0; j < fieldList.size(); j++) {
                    cell = row.createCell(j);
                    Object object = srcMap.get(fieldList.get(j));
                    if (object != null) {
                        if (object instanceof BigDecimal){
                            cell.setCellValue(Double.parseDouble(object.toString()));
                            cell.setCellType(HSSFCell.CELL_TYPE_NUMERIC);
                        }else {
                            cell.setCellValue(object.toString());
                        }
                    } else {
                        if (object instanceof BigDecimal){
                            cell.setCellValue(0);
                            cell.setCellType(HSSFCell.CELL_TYPE_NUMERIC);
                        }else{
                            cell.setCellValue("");
                        }
                    }
                    //设置单元格类型
                }
            }
        }
        setSizeColumn(sheet,fieldList.size()==0?1:fieldList.size());
        response.setContentType("application/vnd.ms-excel;charset=utf-8");
        response.addHeader("Content-Disposition", "attachment; filename=" + new String(fileName.getBytes("utf-8"), "iso8859-1") + ".xlsx");
        response.flushBuffer();
        OutputStream outputStream = response.getOutputStream();
        wb.write(response.getOutputStream());
        wb.close();
        outputStream.flush();
        outputStream.close();
    }
    // 自适应宽度(中文支持)
    private void setSizeColumn(XSSFSheet sheet, int size) {
        for (int columnNum = 0; columnNum < size; columnNum++) {
            int columnWidth = sheet.getColumnWidth(columnNum) / 256;
            System.out.println(sheet.getLastRowNum());
            for (int rowNum = 0; rowNum <= sheet.getLastRowNum(); rowNum++) {
                XSSFRow currentRow;
                //当前行未被使用过
                if (sheet.getRow(rowNum) == null) {
                    currentRow = sheet.createRow(rowNum);
                } else {
                    currentRow = sheet.getRow(rowNum);
                }
                if (currentRow.getCell(columnNum) != null) {
                    XSSFCell currentCell = currentRow.getCell(columnNum);
                    if (currentCell.getCellType() == XSSFCell.CELL_TYPE_STRING) {
                        int length = currentCell.getStringCellValue().getBytes().length;
                        if (columnWidth < length) {
                            columnWidth = length;
                        }
                    }
                }
            }
            sheet.setColumnWidth(columnNum, columnWidth * 256);
        }
    }
    public static void main(String[] args) throws NoSuchFieldException {
        ExportOutOfYardVO vo = new ExportOutOfYardVO();
        vo.setCarNo("1");
        vo.setFeeStandardName("322");
        vo.setEnterTime(new Date());
        vo.setLeaveTime(new Date());
        vo.setMoney(new BigDecimal("2324"));
        System.out.println( ExportOutOfYardVO.class.getFields().length);
//        for (int i=0; i< ExportOutOfYardVO.class.getFields().length;i++){
//            String a = ExportOutOfYardVO.class.getFields()[i].getAnnotation(ApiModelProperty.class).value();
//            String b = ExportOutOfYardVO.class.getFields()[i].getName();
//            System.out.println(a);
//            System.out.println(b);
//        }
        Object o = new BigDecimal("0.01");
        System.out.println(String.valueOf(o));
        String a = String.valueOf(o);
        System.out.println(a ==null);
        System.out.println(a.equals("null"));
        if (o instanceof BigDecimal){
            System.out.println("1122---22");
            System.out.println(o);
        }
    }
}