Java EE is mainly used for the development of Web Application and as we know there are number of other things apart from only java lines are coming into picture for eg : session Management,Security of Transaction,Concurrent behavior of transaction,Work in distributed environment,persistence,locking,ratio to serve request per hit of URL many more ...... and for that Using Java EE we can achieve that as having various different opensource technologies are available
Spring Framework,
EJB
Struts
Hibernate(ORM framework)
iBaties
JSF
jsp+Servlet
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Many other technologies can be helpful to develop web application.