Object Storage Service:Streaming download (Android SDK)

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

Synchronous call:

// Create a request to download an object.
// Specify the bucket name, for example, examplebucket, and the full path of the object, for example, exampledir/exampleobject.txt. The full path of the object cannot contain the bucket name.
GetObjectRequest get = new GetObjectRequest("examplebucket", "exampledir/exampleobject.txt");

// Set the 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 {
    // Synchronously execute the download request and return the result.
    GetObjectResult getResult = oss.getObject(get);

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

    // Get 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, such as displaying an image or writing the data to a file.
    }

    // After the download, you can view the object metadata.
    ObjectMetadata metadata = getResult.getMetadata();
    Log.d("ContentType", metadata.getContentType());


} catch (ClientException e) {
    // Handle local 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();
}

Asynchronous invocation:

// Create a request to download an object.
// Specify the bucket name, for example, examplebucket, and the object's full path, for example, exampledir/exampleobject.txt.
// The object's full path cannot contain the bucket name.
GetObjectRequest get = new GetObjectRequest("examplebucket", "exampledir/exampleobject.txt");

// Set the 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 local 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.