My question is: is there any template system for Java Web Service which helps me build HTML document and return it to client? Something that act like a JSP to servlet. I don't like to embed HTML inside web service method this way.
If you are talking about a RESTful web service architecture, why not use JSP?
If you are talking about a SOAP web service - no, you are stuck with the very formal SOAP API for which there are toolkits.