JSP and JS are completely unrelated. JS (javascript) runs on the client side in browsers and on the server side in NodeJS and one of the Java scripting JSRs. JSP, or Java server pages, are based on a language called Java (not the same as Javascript).
However, consider
bitcoinj. If you have hosting that doesn't overly restrict you and you can open arbitrary network connections (both outbound and inbound) and store files to the filesystem, you should be able to use it. It will actually perform block and txn verification, and can operate in SPV mode (no need to download entire blockchain, but slightly less secure). I have some experience with it, so I can help if needed.
However, I would advise not trying to do bitcoinj stuff in JSPs. Use a ServletContextListener to start bitcoinj's network and verification threads to perform tasks asynchronously.
