1、添加maven依赖

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>3.17</version>
</dependency>

2、ExcelUtil工具类

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.xssf.streaming.SXSSFWorkbook;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.util.List;

public class ExcelUtil {
   /**
    * 导出Excel,一个sheet
    *
    * @param response   响应
    * @param fileName   文件名
    * @param columnList 每列的标题名
    * @param dataList   导出的数据
    */
   public static void exportExcel(HttpServletResponse response, String fileName, List<String> columnList, List<List<String>> dataList) {
      //声明输出流
      OutputStream os = null;
      //设置响应头
      setResponseHeader(response, fileName);
      try {
         //获取输出流
         os = response.getOutputStream();
         //内存中保留1000条数据，以免内存溢出，其余写入硬盘
         SXSSFWorkbook wb = new SXSSFWorkbook(1000);
         //获取该工作区的第一个sheet
         Sheet sheet1 = wb.createSheet("sheet1");
         int excelRow = 0;
         //创建标题行
         Row titleRow = sheet1.createRow(excelRow++);
         for (int i = 0; i < columnList.size(); i++) {
            //创建该行下的每一列，并写入标题数据
            Cell cell = titleRow.createCell(i);
            cell.setCellValue(columnList.get(i));
         }
         //设置内容行
         if (dataList != null && dataList.size() > 0) {
            //序号是从1开始的
            int count = 1;
            //外层for循环创建行
            for (int i = 0; i < dataList.size(); i++) {
               Row dataRow = sheet1.createRow(excelRow++);
               //内层for循环创建每行对应的列，并赋值
               for (int j = -1; j < dataList.get(0).size(); j++) {//由于多了一列序号列所以内层循环从-1开始
                  Cell cell = dataRow.createCell(j + 1);
                  if (j == -1) {//第一列是序号列，不是在数据库中读取的数据，因此手动递增赋值
                     cell.setCellValue(count++);
                  } else {//其余列是数据列，将数据库中读取到的数据依次赋值
                     cell.setCellValue(dataList.get(i).get(j));
                  }
               }
            }
         }
         //将整理好的excel数据写入流中
         wb.write(os);
      } catch (IOException e) {
         e.printStackTrace();
      } finally {
         try {
            // 关闭输出流
            if (os != null) {
               os.close();
            }
         } catch (IOException e) {
            e.printStackTrace();
         }
      }
   }

   /*
      设置浏览器下载响应头
    */
   private static void setResponseHeader(HttpServletResponse response, String fileName) {
      try {
         try {
            fileName = new String(fileName.getBytes(), "ISO8859-1");
         } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
         }
         response.setContentType("application/octet-stream;charset=UTF-8");
         response.setHeader("Content-Disposition", "attachment;filename=" + fileName);
         response.addHeader("Pargam", "no-cache");
         response.addHeader("Cache-Control", "no-cache");
      } catch (Exception ex) {
         ex.printStackTrace();
      }
   }
}

3、导出代码

List<List<String>> dataList = new ArrayList<>();

List<String> stringList = new ArrayList();
stringList.add("130000");
stringList.add("河北");
dataList.add(stringList);

stringList = new ArrayList();
stringList.add("130100");
stringList.add("石家庄");
dataList.add(stringList);

List<String> titleList = Arrays.asList("序号", "编码", "名称");
ExcelUtil.exportExcel(response, "区划信息.xlsx", titleList, dataList);

4、导出效果