1.ExportSelectXlsWorkBookUtils

import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.streaming.SXSSFWorkbook;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Date;
import java.util.List;

import static org.springframework.util.StringUtils.capitalize;
/**
 * 选择字段导出excel
 * dataList：数据源
 * exportFields：列名
 * heards：字段名也就是excel首行
 * excelName：sheet名
 */
public class ExportSelectXlsWorkBookUtils {
     public static void getWorkBook(List<?> dataList, HttpServletResponse response, List<String> exportFields, List<String> heards, String excelName) {
      // 创建工作簿对象
        Workbook workbook = new SXSSFWorkbook();
        // 创建工作表对象
        Sheet sheet = workbook.createSheet(excelName);
        //第一行 标题行
        Row oneHeaderRow = sheet.createRow(0);
        Cell oneHeaderCell = oneHeaderRow.createCell(0);
        oneHeaderCell.setCellValue(excelName);
        // 合并单元格，参数依次为起始行，结束行，起始列，结束列 (索引0开始)
        sheet.addMergedRegion(new CellRangeAddress(0, 0, 0, exportFields.size() - 1));//标题合并单元格操作，6为总列数
        CellStyle oneCellStyle = workbook.createCellStyle();
        oneCellStyle.setAlignment(HorizontalAlignment.CENTER);//设置水平居中
        oneCellStyle.setVerticalAlignment(VerticalAlignment.CENTER);//设置垂直居中
        oneHeaderCell.setCellStyle(oneCellStyle);
        // 创建字体对象
        Font oneHeaderFont = workbook.createFont();
        oneHeaderFont.setFontName("黑体");
        oneHeaderFont.setFontHeightInPoints((short) 16);
        // 将字体应用于单元格样式
        oneCellStyle.setFont(oneHeaderFont);
        // 应用样式到单元格
        oneHeaderCell.setCellStyle(oneCellStyle);

        // 第二行 小标题行
        Row headerRow = sheet.createRow(1);
        // 根据导出字段列表创建表头单元格
        for (int i = 0; i < exportFields.size(); i++) {
            Cell headerCell = headerRow.createCell(i);
            headerCell.setCellValue(heards.get(i));
            CellStyle cellStyle = workbook.createCellStyle();
            cellStyle.setAlignment(HorizontalAlignment.CENTER);//设置水平居中
            cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);//设置垂直居中
            sheet.setColumnWidth(i, 256 * 25 + 184);//设置宽度 这里的25对应excel中的列宽
            cellStyle.setWrapText(true);// 设置自动换行
            headerCell.setCellStyle(cellStyle);
            // 创建字体对象
            Font headerFont = workbook.createFont();
            headerFont.setFontName("黑体");
            headerFont.setFontHeightInPoints((short) 14);
            // 将字体应用于单元格样式
            cellStyle.setFont(headerFont);
            // 应用样式到单元格
            headerCell.setCellStyle(cellStyle);
        }


        // 创建数据行
        for (int rowIndex = 0; rowIndex < dataList.size(); rowIndex++) {
            Row dataRow = sheet.createRow(rowIndex + 2);//这里+2因为我已经给第一行设置了值
            // 获取数据对象
            Object dataObj = dataList.get(rowIndex);
            // 遍历导出字段列表
            for (int colIndex = 0; colIndex < exportFields.size(); colIndex++) {
                String fieldName = exportFields.get(colIndex);
                try {
                    // 根据字段名获取对应的 getter 方法
                    Method method = dataObj.getClass().getMethod("get" + capitalize(fieldName));
                    // 调用 getter 方法获取字段值
                    Object fieldValue = method.invoke(dataObj);
                    // 创建单元格并设置字段值
                    Cell dataCell = dataRow.createCell(colIndex);
                    CellStyle cellStyle = workbook.createCellStyle();
                    cellStyle.setAlignment(HorizontalAlignment.CENTER);//设置水平居中
                    cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);//设置垂直居中
                    sheet.setColumnWidth(colIndex, 256 * 25 + 184);//设置宽度 这里的25对应excel中的列宽
                    dataCell.setCellStyle(cellStyle);
                    if (fieldValue instanceof String) {
                        dataCell.setCellValue((String) fieldValue);
                    } else if (fieldValue instanceof Number) {
                        dataCell.setCellValue(((Number) fieldValue).doubleValue());
                    } else if (fieldValue instanceof Date) {
                        dataCell.setCellValue((Date) fieldValue);
                    } else if (fieldValue instanceof Boolean) {
                        dataCell.setCellValue((Boolean) fieldValue);
                    } else {
                        dataCell.setCellValue(String.valueOf(fieldValue));
                    }
                } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
                    e.printStackTrace();
                }
            }
        }
        // 设置响应头信息
        response.setContentType("application/vnd.ms-excel");
        response.setHeader("Content-disposition", "attachment;filename=" + excelName + ".xls");
        try {
            // 将工作簿写入响应输出流中
            workbook.write(response.getOutputStream());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

2.controller

	/**
	 * 选择字段导出excel
	 * @param deviceProperties
	 * @param response
	 */
	@RequestMapping(value = "/exportSelectXls", method = RequestMethod.POST)
	@ApiOperation(value = "硬件设备台账-选择字段导出excel", notes = "硬件设备台账-选择字段导出excel")
	public void exportSelectXls(DeviceProperties deviceProperties, HttpServletResponse response){
		devicePropertiesService.exportSelectXls(deviceProperties,response,deviceProperties.getExportFields(),deviceProperties.getHeards());
	}

3.service

    void exportSelectXls(DeviceProperties deviceProperties, HttpServletResponse response, List<String> exportFields, List<String> heards);

4.impl

  // 从数据库中获取需要导出的数据
        QueryWrapper query = new QueryWrapper(deviceProperties);
        List<DeviceProperties> dataList = devicePropertiesService.list(query);   
        ExportSelectXlsWorkBookUtils.getWorkBook(dataList, response, exportFields, heards, "硬件设备");
    }