code: public void readBlobTo(String key, OutputStream out) throws IOException, KeyNotFoundException {
          InputStreamWithMeta in = getBlob(key);
          if (in == null) {
              throw new IOException("Could not find " + key);
          }
          byte[] buffer = new byte[2048];
          int len = 0;
          try{
              while ((len = in.read(buffer)) > 0) {
                  out.write(buffer, 0, len);
              }
          } finally {
              in.close();
              out.flush();
          }
      }
docs: Reads the blob from the blob store
  and writes it into the output stream.
  @param key Key for the blob.
  @param out Output stream
  privilege for the blob.
  @throws IOException
  @throws KeyNotFoundException