apache poi Excel导出动态设置下拉框数据

代码涉及到业务，仅供参考，请根据个人业务自行修改。

package com.twqc.modules.lowcode.bpm.utils;

import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.util.CellRangeAddressList;
import org.apache.poi.xssf.streaming.SXSSFWorkbook;
import org.springframework.stereotype.Component;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Map;

/**
 * @author wsl
 * @date 2023/6/14
 */
@Component
public class ExcelHutoolUtil {

    /**
     * 获取表头样式
     *
     * @param workbook 工作簿
     * @return CellStyle 表头样式
     */
    public CellStyle getHeadStyle(Workbook workbook) {
        CellStyle headerStyle = workbook.createCellStyle();
        headerStyle.setAlignment(HorizontalAlignment.CENTER);
        headerStyle.setVerticalAlignment(VerticalAlignment.CENTER);
        headerStyle.setBorderTop(BorderStyle.THIN);
        headerStyle.setBorderBottom(BorderStyle.THIN);
        headerStyle.setBorderLeft(BorderStyle.THIN);
        headerStyle.setBorderRight(BorderStyle.THIN);
        headerStyle.setFillForegroundColor(IndexedColors.GREY_25_PERCENT.getIndex());
        headerStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
        Font headerFont = workbook.createFont();
        headerFont.setFontHeightInPoints((short) 12);
        headerFont.setBold(true);
        headerStyle.setFont(headerFont);
        return headerStyle;
    }

    /**
     * 获取表体样式
     *
     * @param workbook 工作簿
     * @return CellStyle 表体样式
     */
    public CellStyle getBodyStyle(Workbook workbook) {
        // 创建内容样式
        CellStyle style = workbook.createCellStyle();
        style.setAlignment(HorizontalAlignment.CENTER);
        style.setVerticalAlignment(VerticalAlignment.CENTER);
        style.setBorderTop(BorderStyle.THIN);
        style.setBorderBottom(BorderStyle.THIN);
        style.setBorderLeft(BorderStyle.THIN);
        style.setBorderRight(BorderStyle.THIN);
        Font contentFont = workbook.createFont();
        contentFont.setFontHeightInPoints((short) 11);
        style.setFont(contentFont);
        return style;
    }

    /**
     * 导出Excel
     */
    public void exportExcel(SXSSFWorkbook workbook, List> dataList, List> fieldList, String sheetName) {
        Sheet sheet = workbook.createSheet(sheetName);
        // 设置表头
        Row headerRow = sheet.createRow(0);
        for (int i = 0; i < fieldList.size(); i++) {
            Map map = fieldList.get(i);
            String columnName = map.get("name").toString();
            // 必填项标识*，放在列名前面，例：*姓名
            if (null != map.get("mustFlag") && "1".equals(map.get("mustFlag").toString())) {
                String asterisk = "*";
                columnName = asterisk + columnName;
            }
            Cell headerCell = headerRow.createCell(i);
            headerCell.setCellValue(columnName);
            CellStyle headStyle = getHeadStyle(workbook);
            headerCell.setCellStyle(headStyle);
            // 判断当前列是否为importOrgType列，如果是则设置下拉框的数据验证
            if (isImportOrgTypeColumn(map)) {
                Sheet orgTypeSheet = getOrgTypeSheet(workbook, map);
                // 设置下拉框的数据验证
                setDropDownValidation(sheet, i, 1, 999, orgTypeSheet);
            }
        }
        // 输出内容
        if (dataList != null && !dataList.isEmpty()) {
            int rowIndex = 1;
            CellStyle bodyStyle = getBodyStyle(workbook);
            CreationHelper creationHelper = workbook.getCreationHelper();
            for (Map map : dataList) {
                Row row = sheet.createRow(rowIndex++);
                for (int i = 0; i < fieldList.size(); i++) {
                    Map fieldMap = fieldList.get(i);
                    String columnName = fieldMap.get("code").toString();
                    Object value = map.get(columnName);
                    Cell cell = row.createCell(i);
                    if (value instanceof Date) {
                        cell.setCellValue((Date) value);
                        bodyStyle.setDataFormat(creationHelper.createDataFormat().getFormat("yyyy-MM-dd HH:mm:ss"));
                        cell.setCellStyle(bodyStyle);
                    } else {
                        cell.setCellValue(value != null ? value.toString() : "");
                        cell.setCellStyle(bodyStyle);
                    }
                }
            }
        }
        // 设置列宽
        for (int i = 0; i < fieldList.size(); i++) {
            sheet.setColumnWidth(i, 25 * 256);
        }
    }

    /**
     * 判断当前列是否为importOrgType列
     *
     * @param map 字段信息
     * @return boolean
     */
    private boolean isImportOrgTypeColumn(Map map) {
        return "importOrgType".equals(map.get("code").toString());
    }

    /**
     * 获取机构下拉框数据Sheet
     *
     * @param workbook 工作簿
     * @param map      字段信息
     * @return 机构下拉框数据Sheet
     */
    public Sheet getOrgTypeSheet(SXSSFWorkbook workbook, Map map) {

        String name = map.get("name").toString();
        name = name.replace("*", "");
        List dropDownList = new ArrayList<>();
        // TODO 设置dropDownList数据，这里省略......
        // 创建"机构下拉框数据" Sheet并隐藏
        Sheet dropDownSheet = workbook.createSheet("机构下拉框数据");
        workbook.setSheetHidden(workbook.getSheetIndex(dropDownSheet), true);
        // 添加下拉框选项到"网格下拉框数据" sheet
        for (int i = 0; i < dropDownList.size(); i++) {
            Row row = dropDownSheet.createRow(i);
            Cell cell = row.createCell(0);
            cell.setCellValue(dropDownList.get(i));
        }
        return dropDownSheet;
    }

    /**
     * 设置下拉框数据验证
     *
     * @param sheet         工作表
     * @param columnIndex   列索引
     * @param startRow      开始行
     * @param endRow        结束行
     * @param dropDownSheet 下拉框数据Sheet
     */
    public void setDropDownValidation(Sheet sheet, int columnIndex, int startRow, int endRow, Sheet dropDownSheet) {
        int lastRowNum = dropDownSheet.getLastRowNum();
        CellRangeAddressList addressList = new CellRangeAddressList(startRow, endRow, columnIndex, 0);
        // 创建下拉框数据验证对象，并设置数据来源为Sheet2的第一列数据
        DataValidationHelper validationHelper = sheet.getDataValidationHelper();
        String formula = dropDownSheet.getSheetName() + "!$A$1:$A$" + (lastRowNum + 1);
        DataValidationConstraint constraint = validationHelper.createFormulaListConstraint(formula);
        DataValidation validation = validationHelper.createValidation(constraint, addressList);
        // 将下拉框数据验证对象应用到Sheet1的指定列
        sheet.addValidationData(validation);
    }

}