从 Azure Blob 存储读取和写入 excel 文件，无需将其下载到 Java 中的本地文件

Question

我正在使用azure-storage依赖项创建 azure 目录的引用，然后在本地系统中下载文件后，我可以使用poi-ooxml 库进行读写，然后再次在 azure 存储中上传相同的文件。

我只想删除这个本地下载的东西。 有什么方法可以在不下载本地的情况下读取和写入excel文件。

使用的依赖项。

    <dependency>
        <groupId>com.microsoft.azure</groupId>
        <artifactId>azure-storage</artifactId>
        <version>8.4.0</version>
    </dependency>
    
    <dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi</artifactId>
        <version>3.15</version>
    </dependency>
    
    <dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi-ooxml</artifactId>
        <version>3.15</version>
    </dependency>

代码

try {
        CloudStorageAccount storageAccount = CloudStorageAccount.parse(storageConnectionString);
        CloudBlobClient blobClient = storageAccount.createCloudBlobClient();
        CloudBlobContainer container = blobClient.getContainerReference(containerName);
        CloudBlobDirectory downloadDirectory = container.getDirectoryReference(dowloadDirectoryName);

        for(ListBlobItem blobItem: downloadDirectory.listBlobs()) {

            if(blobItem instanceof CloudBlockBlob) {

                CloudBlockBlob cloudBlob = (CloudBlockBlob) blobItem;
                File inputFile = new File(cloudBlob.getName());
                cloudBlob.downloadToFile(inputFile.getAbsolutePath());
                
                FileInputStream inputStream = new FileInputStream(inputFile);
                Workbook workbook = new HSSFWorkbook(inputStream); 
                /*Workbook workbook = WorkbookFactory.create(inputFile);*/
                Sheet sheet = workbook.getSheetAt(0);       
                log.info("Cell No 0 : "+sheet.getRow(0).getCell(0).getStringCellValue());
                for (int i = 1; i <= sheet.getLastRowNum(); i++) {
                    Cell reasonLabel = sheet.getRow(i).createCell(2);
                    reasonLabel.setCellValue("Added one cell");
                }
                
                File outputFile = new File(cloudBlob.getName().split("\\.")[0]+"01.xls");
                FileOutputStream outputStream = new FileOutputStream(outputFile);
                workbook.write(outputStream);
                outputStream.close();
                workbook.close();
                
                CloudBlobDirectory uploadDirectory =  container.getDirectoryReference(uploadDirectoryName);
                CloudBlockBlob uploadBlob = uploadDirectory.getBlockBlobReference(outputFile.getName());
                FileInputStream fileInputStream = new FileInputStream(outputFile);
                uploadBlob.upload(fileInputStream, outputFile.getTotalSpace());
                fileInputStream.close();
                outputFile.delete();
                
            }
        }
    } catch(Exception ex) {
        log.error(ex.getMessage());
        throw ex;
    }

Answer 1

这是我使用 NPOI 从 Azure blob 读取文件的灵魂

foreach (var blob in blobContainer.GetBlobs())
        {
            var blobClient = blobContainer.GetBlobClient(blob.Name);

            using MemoryStream memStream = new();
            blobClient.DownloadTo(memStream);
            memStream.Position = 0;
            var wb = new XSSFWorkbook(memStream);
            sheetName = wb.GetSheetAt(0).SheetName;
            sheet = (XSSFSheet)wb.GetSheet(sheetName);
}