The Windows Azure Blob Service allows metadata and properties to be associated with a blob. The metadata comprises a sequence of developer-defined, name-value pairs. The properties comprise HTTP request headers including: Cache-Control, Content-Encoding, Content-MD5, and Content-Type. The Blob service also supports metadata and properties for blob containers. Requesting a download of the blob attributes—its metadata and properties—is an efficient way of checking blob existence as only a small amount of data is downloaded.
The Blob service uses the Content-MD5 property to validate blob upload. When specified, the Content-MD5 property must be set to the base64-encoded value of the MD5 hash of the blob data. The Blob service returns an error if this value does not match the value it calculates from the uploaded blob content.
In this recipe, we will learn how to set and get blob properties and metadata. We will also learn how to calculate the Content...