首先我们需要导入下面的三个依赖:

       cn.hutool
       hutool-all
       5.2.3
 
       org.apache.poi
       poi-ooxml
       4.1.1
 
       org.apache.poi
       poi-ooxml-schemas
       3.17

测试代码:

@RestController
public class Controller {
    @GetMapping("/downloadExcel")
    @ResponseBody
    public void downLoadFile(HttpServletResponse response) {
        List employees = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            employees.add(new Employee(i + 18, "a" + i));
        }
 
        ExcelWriter writer = ExcelUtil.getWriter();
        writer.addHeaderAlias("name", "姓名");
        writer.addHeaderAlias("age", "年龄");
        writer.merge(1, "员工信息表");
        writer.write(employees, true);
        response.setContentType("application/vnd.ms-excel;charset=utf-8");
 
        String name = StringUtils.toUtf8String("XXX国际贸易公司");
 
        response.setHeader("Content-Disposition", "attachment;filename=" + name + ".xls");
        ServletOutputStream out = null;
        try {
            out = response.getOutputStream();
            writer.flush(out, true);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            writer.close();
        }
        IoUtil.close(out);
    }
 
}