1. A method for classifying a uniform resource locator (URL), the method comprising: configuring a bloom filter to identify a pre-determined set of URL categories; programming the bloom filter with a set of URLs, each URL in the set of URLs belonging to a respectively corresponding URL category of the pre-determined URL categories; extracting a second URL in-line with a data transmission from a network packet stream; determining a set of hash strides for the second URL; querying the bloom filter with each hash stride of the set of hash strides, the querying being performed in a data plane; identifying a sub-set of categories from the pre-determined set of URL categories, the sub-set of categories being URL categories that correspond to the second URL; determining a first URL category based, at least in part, on a programmable mapping table that defines the sub-set of URL categories as the first URL category; and reporting the first URL category as a classification of the second URL in human-readable form.