Thursday 10 April 2014

J2EE

J2EE??
J2EE stands for Java to Enterprise edition.Upto 2013 we wereusing J2EE version 6.But in 2013 sun released new version of J2EE 7 with some blasting features...(will update soon....)


  • J2EE is a platform for delivering enterprise applications. But what does it mean to say that J2EE is a platform? J2EE isn't hardware, although it can run on any hardware with an appropriate JVM. And J2EE isn't software exactly, since many vendors provide J2EE-compatible systems, and even provide their own JVMs. So what sort of a platform is J2EE, since it's neither a hardware platform, nor a specific software product?
  • In the world of software, a platform is a combination of hardware and software necessary to run applications.


 Basic J2EE Overview diagram



  • Business Layer:Any kind of Database interactions done by JPA(Java Persistence API).
  • Different persistence offered by Java--
                   JDBC
                   JDO(Java data object)
                   JPA(POJO based)
                   Entity Beans
  • Service Layer will use JPA to interact with database.
  • Service layer(EJB) deals with all bussiness operations eg.,sending mails,sending messages to message queuesand any business logic...
  • Web Layer is presentation layer with which clients will interact.Weblayer(JSF) will use the business operations in the service layer(EJB) and the service layer will use with Business layer(JPA) to interact with Database(Oracle/Mysql).
Packaging Structure:
  • Web layer which consists of JSP,JSF,Servlets will be packaged as .war file.
  • The business layer and services layer(means JPA and EJB ) will package together as .jar file.
  • Finally the Jar file and war file will bundled together into .ear file.(ear:enterprise archive)

Top Technologies in J2EE6

Web Services Technologies