How to manage content and optimize usign struts2/JSP

I have a forum running on pure struts2/jsp and MySQL on tomcat 6. Here is how it works currently.
- user logs in and clicks on the forum topic
- DB is queried, and posts populated , and shown to the user.
- if user adds a post, same is inserted and page refreshed.
- even for showing old posts, which dont change with time i query DB

I want to optimize performance by somehow converting the forum pages into htmls, so that i don't need to query DB everytime, because the posts once posted don't change.Only while doing a new post, i should be doing a db call.

Are there any known frameworks I should be using. Is there something i can incorporate into my existing app and improve performance ?