阿里巴巴EasyExcel文件下载代码示例

阿里巴巴开源了一个文件导出的工具easyexcel，可以做文件的上传和下载，简化了复杂的编码工作，下面介绍使如何使用easyexcel下载excel。

一、引入maven依赖

    com.alibaba
    easyexcel
    1.1.2-beat1

二、定义excel表单内容实体

1. 实体继承BaseRowModel
2. 属性增加@ExcelProperty(value = "ID", index = 0)注解，value是excel文件的表头，index是列的序号

示例如下：

@Getter
@Setter
@ToString
public class QuestionExcelData extends BaseRowModel {

    @ExcelProperty(value = "ID", index = 0)
    private Long id;
    /**
     * 模块
     */
    @ExcelProperty(value = "模块", index = 1)
    private String system;
    /**
     * 具体问题
     */
    @ExcelProperty(value = "反馈问题", index = 2)
    private String question;
    /**
     * 问题是否已解决
     */
    @ExcelProperty(value = "是否修复", index = 4)
    private String repaired;
}

三、controller层响应流式下载

@RequestMapping("/export")
public void exporExcel() throws IOException {

  log.info("反馈问题导出 -> 开始");
  ExcelWriter writer = null;
  OutputStream outputStream = response.getOutputStream();
  try {
    //添加响应头信息
    String fileName = "商羚反馈问题列表-" + LocalDate.now().format(DateTimeFormatter.BASIC_ISO_DATE) +".xls";
    response.setHeader("Content-disposition", "attachment; filename=" + new String(fileName.getBytes(StandardCharsets.UTF_8),"ISO8859-1"));
    response.setContentType("application/msexcel;charset=UTF-8");//设置类型
    response.setHeader("Pragma", "No-cache");//设置头
    response.setHeader("Cache-Control", "no-cache");//设置头
    response.setDateHeader("Expires", 0);//设置日期头

    //实例化 ExcelWriter
    writer = new ExcelWriter(outputStream, ExcelTypeEnum.XLS, true);

    //实例化表单
    Sheet sheet = new Sheet(1, 0, QuestionExcelData.class);
    sheet.setSheetName("反馈问题");

    //获取数据
    List questionExcelDataList = fetchExcelData();
    //输出
    writer.write(questionExcelDataList, sheet);
    writer.finish();
    outputStream.flush();
    log.info("反馈问题导出 -> 完成");
  } catch (IOException e) {
    e.printStackTrace();
  } finally {
    try {
      response.getOutputStream().close();
    } catch (IOException e) {
      e.printStackTrace();
      //TODO 异常处理
    }
  }
}

/**
     * 获取填充数据
     * @return
     */
private List fetchExcelData() {
  List dutyQuestionList = questionService.queryQuestion(null);
  List questionExcelDataList = BeanCopierUtil.convertList(dutyQuestionList, QuestionExcelData.class);
  log.info("反馈问题导出 -> 查询到数据:{}", JSON.toJSONString(questionExcelDataList));
  return questionExcelDataList;
}