SSM框架使用poi导入导出Excel的详细方法

  <!--POI-->
    <dependency>
      <groupId>org.apache.poi</groupId>
      <artifactId>poi-ooxml-schemas</artifactId>
      <version>3.14-beta1</version>
    </dependency>

     <!--文件上传依赖-->
    <dependency>
      <groupId>commons-fileupload</groupId>
      <artifactId>commons-fileupload</artifactId>
      <version>1.2.2</version>
    </dependency>
    <dependency>
      <groupId>commons-io</groupId>
      <artifactId>commons-io</artifactId>
      <version>2.4</version>
    </dependency>  

 <!-- 配置文件上传解析器 -->
  <!-- id 的值是固定的-->
  <bean id="multipartResolver"
     class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
    <!-- 设置上传文件的最大尺寸为 5MB -->
    <property name="maxUploadSize">
      <value>5242880</value>
    </property>
  </bean>

<!-- excel文件导出 -->
<p><a href="User/exportExcel.do" rel="external nofollow" >导出</a>
<!-- excel文件导入 -->
<form action="User/importExcel.do" method="post" enctype="multipart/form-data">
  <input type="file" name="userExcel" />
  <input type="submit" value="导入">
</form>

public class User {
  private Integer id;
  private String username;
  private String password;
  /* get 和 set */
  }

 /**
   * 导出Excel
   * @param request
   * @param response
   */
  @RequestMapping("/exportExcel")
  @ResponseBody
  public void exportExcel(HttpServletRequest request, HttpServletResponse response){
    try {
      //获取数据源
      List<User> userList = service.queryUserAll();
      //导出excel
      response.setHeader("Content-Disposition","attachment;filename="+new String("用户信息.xls".getBytes(),"ISO-8859-1"));
      response.setContentType("application/x-excel;charset=UTF-8");
      OutputStream outputStream = response.getOutputStream();
      //导出
      service.exportExcel(userList,outputStream);
      outputStream.close();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }

/**
   * 导入exc
   * @param userExcel
   * @param request
   * @param session
   * @return
   */

  @RequestMapping("/importExcel")
  @ResponseBody
  public String importExcel(MultipartFile userExcel, HttpServletRequest request, HttpSession session) throws IOException, InvalidFormatException {
    if(userExcel == null){
      session.setAttribute("excelName", "未上传文件，上传失败！");
      return null;
    }
    String userExcelFileName = userExcel.getOriginalFilename();
    if(!userExcelFileName.matches("^.+\\.(?i)((xls)|(xlsx))$")){
      session.setAttribute("excelName", "文件格式不正确！请使用.xls或.xlsx后缀的文档，导入失败！");
      return null;
    }
    //导入
      service.importExcel(userExcel);
      session.setAttribute("excelName", "导入成功！");
      return "redirect:queryUserAll.do";
  }