Object Storage Service:Streaming download

Usage notes

• Before you run the sample code in this topic, you must create an OSSClient instance by using methods such as using a custom domain name or Security Token Service (STS). For more information, see Initialization.

Examples

The following sample code provides an example on how to synchronously perform streaming download:

// Construct an object download request. 
// Specify the name of the bucket and the full path of the object. In this example, the bucket name is examplebucket and the full path of the object is exampledir/exampleobject.txt. Do not include the bucket name in the full path of the object. 
GetObjectRequest get = new GetObjectRequest("examplebucket", "exampledir/exampleobject.txt");

// Configure a download progress callback. 
get.setProgressListener(new OSSProgressCallback<GetObjectRequest>() {
            @Override
            public void onProgress(GetObjectRequest request, long currentSize, long totalSize) {
                OSSLog.logDebug("getobj_progress: " + currentSize+"  total_size: " + totalSize, false);
            }
        });

try {
    // Process the download request synchronously and obtain the result. 
    GetObjectResult getResult = oss.getObject(get);

    Log.d("Content-Length", "" + getResult.getContentLength());

    // Obtain the input stream of the object. 
    InputStream inputStream = getResult.getObjectContent();

    byte[] buffer = new byte[2048];
    int len;

    while ((len = inputStream.read(buffer)) != -1) {
        // Process the downloaded data. For example, display the image or perform a write operation on the object. 
    }

    // View the object metadata. 
    ObjectMetadata metadata = getResult.getMetadata();
    Log.d("ContentType", metadata.getContentType());


} catch (ClientException e) {
    // Handle client exceptions, such as network exceptions. 
    e.printStackTrace();
} catch (ServiceException e) {
    // Handle service exceptions. 
    Log.e("RequestId", e.getRequestId());
    Log.e("ErrorCode", e.getErrorCode());
    Log.e("HostId", e.getHostId());
    Log.e("RawMessage", e.getRawMessage());
} catch (IOException e) {
    e.printStackTrace();
}

The following sample code provides an example on how to asynchronously perform streaming download:

// Construct an object download request. 
// Specify the name of the bucket and the full path of the object. In this example, the bucket name is examplebucket and the full path of the object is exampledir/exampleobject.txt. 
// Do not include the bucket name in the full path of the object. 
GetObjectRequest get = new GetObjectRequest("examplebucket", "exampledir/exampleobject.txt");

// Configure a download progress callback. 
get.setProgressListener(new OSSProgressCallback<GetObjectRequest>() {
            @Override
            public void onProgress(GetObjectRequest request, long currentSize, long totalSize) {
                OSSLog.logDebug("getobj_progress: " + currentSize+"  total_size: " + totalSize, false);
            }
        });
OSSAsyncTask task = oss.asyncGetObject(get, new OSSCompletedCallback<GetObjectRequest, GetObjectResult>() {
    @Override
    public void onSuccess(GetObjectRequest request, GetObjectResult result) {
        // The request is successful. 
        InputStream inputStream = result.getObjectContent();

        byte[] buffer = new byte[2048];
        int len;

        try {
            while ((len = inputStream.read(buffer)) != -1) {
                // Process the downloaded data. 
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onFailure(GetObjectRequest request, ClientException clientExcepion, ServiceException serviceException) {
        // Handle request exceptions. 
        if (clientExcepion != null) {
            // Handle client exceptions, such as network exceptions. 
            clientExcepion.printStackTrace();
        }
        if (serviceException != null) {
            // Handle service exceptions. 
            Log.e("ErrorCode", serviceException.getErrorCode());
            Log.e("RequestId", serviceException.getRequestId());
            Log.e("HostId", serviceException.getHostId());
            Log.e("RawMessage", serviceException.getRawMessage());
        }
    }
});

References

• For the complete sample code for streaming download, visit GitHub.

• For more information about the API operation that you can call to perform streaming download, see GetObject.

• For more information about how to initialize an OSSClient instance, see Initialization.