J2EE Introduction

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 ppapapetrou76@gmail.com 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 atJ2EE architecture Computer Science Department
• 5.
  A glance atJ2EE 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 atJ2EE 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) EJBas 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 isJava 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) BasicCharacteristics  Syncronization with Java Objects through backing beans  Internationaliztion  Validators & Converters  Several popular implementations • RichFaces • IceFaces • PrimeFaces Computer Science Department
• 16.
  XHTML Overview Why XHTMLinstead 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 withHTML  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 withHTML  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 supportingJ2EE  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 forEJBs...  Tomcat  Jetty not for J2EE...  IIS  Apache HTTP Can you figure out why?? Computer Science Department
• 21.
  A working example MyBlogApplication  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