J2EE Introduction
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This document provides an overview of building web applications with J2EE. It introduces key J2EE concepts and technologies including the J2EE architecture with its layered approach, containers that provide services to components, and common technologies used like EJBs, JSF, XHTML. It also discusses J2EE servers, development lifecycles and tools, and provides an example blog application to demonstrate J2EE concepts in practice. The presentation concludes with a Q&A session.
J2EE Introduction
- 1. Building web applications with J2EE Papapetrou P. Patroklos Software Engineer / Team Leader at OTS SA ( www.ots.gr ) since 1997 Part-time lecturer at City College (MSc) Opensource projects contributor [email protected] http://twitter.com/ppapapetrou76 Computer Science Department
- 2. Overview J2EE Introduction J2EE Technologies J2EE Servers A working example Q&A Session Computer Science Department
- 3. J2EE Introduction What does J2EE stand for? What is its purpose? Why should I learn to develop Web Applications using J2EE technologies? Pros / Cons Differences with other possible solutions Required skills Computer Science Department
- 4. A glance at J2EE architecture Computer Science Department
- 5. A glance at J2EE architecture End-to-End Architecture N-tier Layers Components: handle – Business Logic – Presentation – Persistence Containers – Vendor-specfic Implementations – Strictly follow same rules Computer Science Department
- 6. A glance at J2EE architecture Containers -> work invisible. Provide services for : – Security – Transaction – Persistence – Concurrency – Availability – Life-cycle Management Computer Science Department
- 7. J2EE Development Lifecycle Develop components for – Persistence (Entities) – Business Logic (EJBs) – Presentation (JSF, XHTML) Configure/Prepare deployment descriptors Build Compoments in packages (JARs, WARs, EARs) Deploy packages on Container (J2EE Server) Computer Science Department
- 8. J2EE Development life-cycle - Tools All target to facilitate building documentation and management of (Java) projects Plethora of choices – Maven : stands for Accumulator of Knowledge – Ant – Ivy – Gradle Computer Science Department
- 9. J2EE Technologies Java Persistence API (JPA) Enterprise Java Beans (EJB) eXtended Markup Language (XML) Java Server Faces (JSF) Java API for XML RPC (JAX-RPC) eXtensible HyperText Markup Language (XHTML) Service Oriented Architecture (SOA) Computer Science Department
- 10. Other Related Technologies Cascading Style Sheets (CSS) JavaScript & Jquery Ajax Dependency Injection Frameworks – Google Guice – Spring Source – Jboss Weld ... coming more... Computer Science Department
- 11. EJB Overview What is EJB? A platform for building portable, reusable, and scalable business applications using Java a piece of Java code that executes in a specialized runtime environment called the EJB container EJB is both a component and a framework Computer Science Department
- 12. EJB Overview (cont'd) EJB as a component Persistence Entity Beans Business Logic Session Beans Message-Driven Beans Computer Science Department
- 13. EJB Overview (cont'd) EJB as a framework Out-of-the-box services Available to all components during execution via EJB Container Annotations : The magic wand Specify services, types and behavior Service Oriented Architecture Fast and easy Web Service Creation Computer Science Department
- 14. JSF Overview What is Java Server Faces A component architecture A standard – extendable set of UI Widgets An application infastructure Basic Characteristics Event oriented components Powerful architectures for different Uis (desktop browsers, mobile devices etc.) Flexible Navigation System Computer Science Department
- 15. JSF Overview (cont'd) Basic Characteristics Syncronization with Java Objects through backing beans Internationaliztion Validators & Converters Several popular implementations • RichFaces • IceFaces • PrimeFaces Computer Science Department
- 16. XHTML Overview Why XHTML instead of HTML? A more clean and standard way to write HTML Take advantages of all XML goodies Allows a larger percentage of browsers or code parsers to properly parse pages Use of Templates to facilitate page reusability and “inheritance” Computer Science Department
- 17. XHTML Overview Differences with HTML XHTML elements must be properly nested XHTML elements must always be closed XHTML elements must be in lowercase XHTML documents must have one root element Documents can be validated much easier Computer Science Department
- 18. XHTML Overview Differences with HTML Documents can be transformed via tools like XSLT into other documents for consumption by devices like handhelds Fragments of documents can be retrieved faster Text can be stored more effieciently in object oriented databases Computer Science Department
- 19. J2EE Servers Servers supporting J2EE Oracle/Sun's Glassfish ( http://glassfish.java.net) Apache's Jeronimo ( http://geronimo.apache.org) RedHat's Jboss (http://www.jboss.org ) IBM's Webshpere Oracle's WebLogic Caucho's Resin (http://www.caucho.com) Computer Science Department
- 20. J2EE Servers not for EJBs... Tomcat Jetty not for J2EE... IIS Apache HTTP Can you figure out why?? Computer Science Department
- 21. A working example MyBlog Application MySQL as database layer Entities for persistence layer Session Beans for business logic layer XHTML pages for presentation layer • JSF2 Framework • Extended by PrimeFaces Computer Science Department
- 22. Q&A Session Thank you Time for answers!! Computer Science Department