通过 java MVC 网站的 Azure 存储

Question

我有一个使用 Spring 和 hibernate 框架的 java web 应用程序。我正在 azure 上移动这个网络应用程序。在本地网络应用程序中有一个功能，我首先将图像上传到 C 中的临时文件夹中：然后访问该文件以进行应用程序。上传文件的位置也存储在数据库中以供进一步参考。我已经定义了在属性文件中上传文件并在控制器中通过它访问的基本路径以及用于创建目录、文件名和文件路径的服务层。

谁能告诉我如何使用 azure 存储在 azure 中做同样的事情？任何帮助表示赞赏。

属性文件中的代码：

# Base File Path for Uploading Files 
fileupload.basepath=C:/webApp

创建临时文件夹的代码

    @RequestMapping(value = "/file/upload", method = RequestMethod.POST)
public @ResponseBody
String upload(MultipartHttpServletRequest request,
        HttpServletResponse response) {

    // 0. notice, we have used MultipartHttpServletRequest

    // 1. get the files from the request object
    Iterator<String> itr = request.getFileNames();

    MultipartFile mpf = request.getFile(itr.next());

    if (!CommonUtil.isNull(mpf)) {
        if (mpf.getSize() > ProductCommonConstants.MAX_FILE_UPLOAD_SIZE_IN_BYTES) {
            return CommonConstants.STR_FAILURE;
        }

    }

    long fileName = Calendar.getInstance().getTimeInMillis();

    final String modelImageDirPath = baseUploadFilePath + "/"
            + CommonConstants.TEMP_FILE_NAME;

    // Check for folder existence
    final File modelImageDir = new File(modelImageDirPath);
    if (!modelImageDir.exists()) {
        // Create the directory
        modelImageDir.mkdirs();
    }

    InputStream is = null;
    FileOutputStream fos = null;

    try {
        String contentType = mpf.getContentType();

        if (contentType != null) {

            is = new DataInputStream(mpf.getInputStream());

            // just temporary save file info
            File file = new File(modelImageDirPath + "/" + fileName);

            fos = new FileOutputStream(file);

            // Write to the file
            IOUtils.copy(is, fos);
        }

    } catch (FileNotFoundException ex) {

    } catch (IOException ex) {

    } finally {

        try {
            if (fos != null) {
                fos.close();
            }
            if (is != null) {
                is.close();
            }
        } catch (IOException ignored) {
            // Log the Exception

        }
    }

    // 2. send it back to the client as <img> that calls get method
    // we are using getTimeInMillis to avoid server cached image

    return "/service/common/file/get/" + fileName;

}

}

Answer 1

根据我的经验，您可以使用 Class CloudBlob 的 upload(InputStream sourceStream, long length) 将文件从 Spring MVC MultipartFile 上传到 Azure Blob 存储，请参阅下面从您的代码修改的代码。

@RequestMapping(value = "/file/upload", method = RequestMethod.POST)
public @ResponseBody String upload(MultipartHttpServletRequest request,
        HttpServletResponse response) {
    // 0. notice, we have used MultipartHttpServletRequest
    // 1. get the files from the request object
    Iterator<String> itr = request.getFileNames();
    MultipartFile mpf = request.getFile(itr.next());
    if (!CommonUtil.isNull(mpf)) {
        if (mpf.getSize() > ProductCommonConstants.MAX_FILE_UPLOAD_SIZE_IN_BYTES) {
            return CommonConstants.STR_FAILURE;
        }
    }
    long fileName = Calendar.getInstance().getTimeInMillis();
    // Modified from your code: START
    String storageConnectionString = "DefaultEndpointsProtocol=http;" + "AccountName=your_storage_account;" + "AccountKey=your_storage_account_key";
    CloudStorageAccount storageAccount = CloudStorageAccount.parse(storageConnectionString);
    CloudBlobClient blobClient = storageAccount.createCloudBlobClient();
    CloudBlobContainer container = blobClient.getContainerReference("<blob-container-name>");
    InputStream is = null;
    try {
        String contentType = mpf.getContentType();
        if (contentType != null) {
            is = new DataInputStream(mpf.getInputStream());
            long length = mpf.getSize();
            CloudBlockBlob blob = container.getBlockBlobReference(""+fileName);
            blob.upload(is, length);
        }
    // Modified from your code: END
    } catch (FileNotFoundException ex) {

    } catch (IOException ex) {

    } finally {
        try {
            if (is != null) {
                is.close();
            }
        } catch (IOException ignored) {
            // Log the Exception

        }
    }   
    // 2. send it back to the client as <img> that calls get method
    // we are using getTimeInMillis to avoid server cached image
    return "/service/common/file/get/" + fileName;
}

为了下载或引用blob，您需要将blob的容器名称和blob名称记录到数据库中。

OutputStream os = ...; // get the OutputStream from the HTTP Response
CloudBlobContainer container = blobClient.getContainerReference("<container-name>");
CloudBlob blob = getBlockBlobReference("<blob-name>");
blob.download(os)

有关更多信息，您可以参考 Class CloudBlob http://azure.github.io/azure-storage-java/com/microsoft/azure/storage/blob/CloudBlob.html 的 Javadoc 和 Blob Storage https://azure.microsoft.com/en-us/documentation/articles/storage-java-how-to-use-blob-storage/ 的入门文档。