but another way instead of set email address comes from SSO login page at webapp3 in CATALINA_HOME/conf/web.xml. it may be good idea as all application has access of it,
With all due respect, it is a terrible idea, for multiple reasons; let's just forget about it.
If you can suggest different approach please suggest..
I already suggested a REST service for communicating between web apps. Another approach might be a shared database. But it still sounds as if the SSO subsystem should be able to handle any number of web apps. Or are you saying that the web app that needs this data is NOT governed by the SSO solution? Or that the user will not actually log into the web app that needs this data?
As you have gone an edited your previous posts to be nonsense, it's impossible to offer any further aid. I'm closing this topic. Please open a new topic with the information needed to answer your question, and please do not remove that information at a later time.