1.以下是我封装的Java类

import java.io.FileInputStream;
import java.io.OutputStream;
import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFCellStyle;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
/**
 * 
 * @author HeYunLai
 *
 */
public class ClubMissLiCodeExportUtil {
    
   public static void  exportByTemplate(HttpServletRequest request,HttpServletResponse response,List<List<String>> dataList,String tmpPath,int startRowNum,int sheetNum,String downloadName) throws Exception {
        XSSFWorkbook workbook = getWorkbookTmp(request,tmpPath);
        XSSFSheet sheet = workbook.getSheetAt(sheetNum);
        setDataIntoSheet(sheet,dataList,startRowNum);
        XSSFCellStyle style = workbook.createCellStyle();
        setBorderStyle(style);
        setSheetStyle(sheet,style,startRowNum,(short) 500);
        response.setHeader("Content-Disposition", "attachment; filename=\""
                + new String((downloadName + ".xlsx").getBytes("GBK"),
                        "iso8859-1")
                + "\"");
        response.setHeader("Content-Type", "application/octet-stream");
        OutputStream out = response.getOutputStream();
        workbook.write(out);
        out.close();
        return ;
   }
   /**
    * 获得模板
    * @param request
    * @param tmpPath 例如：/test/a.xlsx
    * @return
    * @throws Exception
    */
   public static XSSFWorkbook getWorkbookTmp(HttpServletRequest request,String tmpPath) throws Exception {
        String filePath = request.getSession().getServletContext().getRealPath(tmpPath);
        XSSFWorkbook workbook = new XSSFWorkbook(new FileInputStream(filePath));
        return workbook; 
   }
   /**
    * 设置样式，有边框、居中
    * @param style
    */
   public static void setBorderStyle(XSSFCellStyle style) {
        style.setBorderBottom(XSSFCellStyle.BORDER_THIN);
        style.setBorderTop(XSSFCellStyle.BORDER_THIN);
        style.setBorderLeft(XSSFCellStyle.BORDER_THIN);
        style.setBorderRight(XSSFCellStyle.BORDER_THIN);
        style.setAlignment(XSSFCellStyle.ALIGN_CENTER);
        style.setVerticalAlignment(XSSFCellStyle.VERTICAL_CENTER);
   }
   /**
    * 往sheet写入数据
    * @param sheet
    * @param dataList 数据
    * @param startRowNum 起始行
    */
   public static void setDataIntoSheet(XSSFSheet sheet, List<List<String>> dataList, int startRowNum) {
        int rowNum = startRowNum;
        XSSFRow row = null;
        XSSFCell cell = null;
        for (List<String> rowData : dataList) {
            row = sheet.createRow(rowNum);
            for (int i = 0; i < rowData.size(); i++) {
                cell = row.createCell(i);
                cell.setCellValue(rowData.get(i));
            }
            rowNum++;
        }
   }
   /**
    * 设置sheet样式
    * @param workbook
    * @param style 每个一格样式
    * @param sheetNum sheet位置
    * @param startRowNum 起始行
    * @param rowHeight 行高，建议500
    */
   public static void setSheetStyle(XSSFSheet sheet, XSSFCellStyle style, int startRowNum,short rowHeight) {
       int rowNum = startRowNum;
       XSSFRow row = null;
       XSSFCell cell = null;
       
       for (int i = rowNum; i < sheet.getLastRowNum()+1; i++) {
            row = sheet.getRow(i);
            row.setHeight(rowHeight);
            for (int j = 0; j < row.getLastCellNum(); j++) {
                cell = row.getCell(j);
                cell.setCellStyle(style);
            }
            rowNum++;
       }
   }

   
   
}

使用示例

       private void test(HttpServletRequest request,HttpServletResponse response) throws Exception {
           List<List<String>> dataList = new ArrayList<>();
            for(int i=0;i<4;i++){
                List<String> data = new ArrayList<>();
                data.add(""+i);
                data.add(""+i);
                data.add(""+i);
                data.add(""+i);
                dataList.add(data);
            }
            String tmpPath = "/cmcc/supplier/common/ping.xlsx";
            int startRowNum = 2;
            int sheetNum = 0;
            String downloadName = "hhh";
            ClubMissLiCodeExportUtil.exportByTemplate(request, response, dataList, tmpPath, startRowNum, sheetNum, downloadName);
            return ;
      }