I saw some people use URLRewriting or URLEncoding and observed that sometimes the URL includes some funny things like %20.. or things like that(after I clicked submit button). It seems some char were changed. If I use "getParameter" to retrieve input value, will this method return me the original input value or such funny modified chars ?
The "funny modified characters" are URL-encoded versions of special characters used within URLs such as =, &, ? and so on. Without encoding, they'll be assumed to be delimiters rather than parts of parameter names or values.