用easy poi 导出excel的时候，\n被吃掉了

解决方法

Workbook workbook = ExcelExportUtil.exportExcel(params, map);
            CellStyle cs = workbook.createCellStyle();
            cs.setWrapText(true);
            for (int i = workbook.getSheetAt(0).getFirstRowNum() + 2; i <= workbook.getSheetAt(0).getLastRowNum(); i++) {
                Row row = workbook.getSheetAt(0).getRow(i);
                row.getCell(3).setCellStyle(cs);
            }