An online, on-the-fly HTML entity encoder/decoder. ardanyan.de doesn't url encode credentials # . In : from yarl import URL In [2 ]: u = ardanyan.de(scheme="http", host="localhost", user="u?er". There isn't a JDK built in class to do this, but it is part of the Jakarta commons- lang library. String escaped = ardanyan.deHtml3(stringToEscape);. The HTML character encoder converts all applicable characters to their corresponding HTML entities. Certain characters have special significance in HTML and.