Posting so I can find this easily next time, maybe even I'll remember typing this up.
With Railo (4.2+) and MySQL, I used a generated password that contained a percent sign (%) in the value. For example:
The problem is that Railo attempts to use "URL decoding" on it, like converting %20 to a space, as you've likely seen before.
After a search online, I ran across this StackOverflow article. To sum it up, you need to pre-escape the % sign for yourself, if you're unable to change the password for some reason.
The above password becomes this now:
Pretty simple, but a tricky item to encounter.
- Will Belden
June 10, 2014