Unescaping / decoding an email address set in a cookie

I've stored an email address in a cookie, and I'm sending it to a jsp file on google appengine 开发者_如何学Goto be verified. The @ is coming through as %40. I need to get it back to an @, and convert any other special chars that might have been encoded. Are there classes available through appengine that deal with this conversion?

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Look at URLDecoder and URLEncoder:

http://download.oracle.com/javase/6/docs/api/java/net/URLDecoder.html

Looking at the JRE whitelist they are both fine to use.