使用ByteArrayOutputStream实现将数据写入本地文件

//测试-将表格导入本地文件
        FileOutputStream fileOutputStream = null;
        try {
            fileOutputStream = new FileOutputStream("C:\\Users\\Administrator.DESKTOP-SFAEOA8\\Desktop\\consistencyCheckCommodityRuleTemplate.xlsx");
            fileOutputStream.write(byteArrayOutputStream.toByteArray());
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

public void uploadExcel() {
 
        //获取校验数据
        List<DTO> consistencyCheck = getConsistencyCheck();
 
        //创建模板信息
        DataModel dataModel = setDataModel();
        ......（此处省略一万字)
 
        //创建ExcelData
        ExcelData excelData = setExcelData();
        ......（此处也省略一万字)
 
        //创建日志数据
        ConsistencyCheckLog consistencyCheckLog = setConsistencyCheckLog();
        ......（此处又省略一万字)
 
        //创建excel
        ByteArrayOutputStream  byteArrayOutputStream = createExcel(dataModel, excelData);
 
        //测试-将表格导入本地文件
        FileOutputStream fileOutputStream = null;
        try {
            fileOutputStream = new FileOutputStream("C:\\Users\\Administrator.DESKTOP-SFAEOA8\\Desktop\\consistencyCheckCommodityRuleTemplate.xlsx");
            fileOutputStream.write(byteArrayOutputStream.toByteArray());
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
 
        //上传excel（无法上传 先注掉好了）
        //uploadFileToDfs(consistencyCheckLog, byteArrayOutputStream);
    }

 // 把读取的结果写入到ByteByteArrayOutputStream
 public static void main(String[] args) throws IOException {
  // TODO Auto-generated method stub
  String s = "C:\\a.txt";
  int len = 0;
  FileInputStream stream = new FileInputStream(s);
  ByteArrayOutputStream stream2 = new ByteArrayOutputStream();
  byte[] buffer = new byte[5];
  //先读后写,循环读写
  while ((len = stream.read(buffer)) != -1) {
   stream2.write(buffer, 0, len);
  }
  byte[] data = stream2.toByteArray();
  System.out.println(new String(data));
 }