There are two kinds of hosting companies in Iran, Those who have their server in iran (obviusly the relieablity is awfull) and those who resell the hosting plans of other companies. (mostly canadian companies) which add comission fee to the original price of the hosting plan. If you have access to credit card or can find somone who accepts to pay for you, it will be cheaper, more reliable and with beter costumer support.
lunarpages.com is one of the best hosting companies that supports JSP/Servlet and ASP with Resin web server (instead of tomcat) but not EJB.(
4java.ca in another one with resonable price and good support. (I have used both)
By the way I have a list of hostings with their prices and services that I gathered 2 years ago, I can send it if you need it.