J2 ee architecture
- 1. Introduction to J2EE
- 2. Enterprise Architecture types Enterprise Architecture can be broken into 3 fundamental layers • User Interface • Processing • Data Storage and access 2
- 3. Types of enterprise architecture 1. Single Tier All 3 layers of enterprise architecture exist on the same system 2.Two Tier Architecture - All 3 layers distributed between 2 tiers - Generally UI and business logic reside on FE and Data Access on Back end 3
- 4. 3. Three tier architecture - All 3 layers separated logically - Physical separation depends on the application - User Interface- client end Processing – Middle / Business Tier(Apps server) Database - Back end 4
- 5. 4. n.Tier Architecture - 2nd layer can be broken into multiple layers User Interface Business model Business rules Business object to data source mapping Data Access 5
- 6. Advantages of n tier 1. Improved maintainablity : Applications can be easily maintained 2. Consistency: In terms of component design 3. Interoperability: Supports component design in any layer and by any technology 4. Flexibility : Freedom to design any type of component 5. Scalability: Addition of new components… 6
- 7. Goals of an Enterprise Architecture • Robust • Performance & Scalability • Capitalize adv of OO Design Priniciple • Avoid complexity • Maintainable and Extensible • Ease of testing • Reuse of application • Support multiple client types • Product delivery on time 7
- 8. What is J2EE?? • Platform used for n tier application development • Compliant with goals of enterprise architecture • Based on Java 2 Platform , standard edition 8
- 9. Benefits of J2EE 1. Simple Architecture - Provision of a variety of ways to configure architecture of an application - supports component based design ( updation, replacement and addition of new functionality can be wired into existing app easily) ( Member with specific skill set develops components under his/her skill area leading to developmental modularization) 9
- 10. 2. Easy association with existing Information system - includes industry accepted APIs thereby enabling to access existing Information systems(J2SE based systems) - Wiring to existing system through a) J2EE connector architecture b) JDBC API c) JNDI d) Java Mail 10
- 11. 3. Freedom of server ,tool and component choice - Organisations have plethora of choices in terms of vendors, hardware, OS,server configuration.( This has created market for servers for J2EE platform) - Component support ensures standardized, packged and reused components.Vendors will be able to provide solutions which will be easily compatible to the current system. 11
- 12. 4. Scalabilty - component design support has improved the scalabilty factor in these application 5. Security model - EJB and Servlet provide programmatic security mechanisms - user based security offered by application at deployment time 12
- 13. Features of JEE • Platform Independence • Managed Objects through containers • Reusability • Modularity • Easy development • Simplified EJB technology • Enhanced Web services • Support for web2.0 • Ease of Application packaging • Light weight JPA(POJO based) 13
- 14. JEE Runtime Infrastructure 14
- 15. • Run time infrastructure is used for managing and hosting applications • Services to manage applications are provided by runtime infrastructure.(platform level) • Services- messaging,security and distributed transactions • JEE accesses the APIs that provide services through containers • J2SE provides core APIs for devloping a JEE application 15
- 16. APIs in JEE 1. Enterprise Java Beans (EJB3.0) - Server side code for business logic - types – session beans & message driven beans - Session bean – conversation with client - message driven bean – session bean + message listener(asynchronous) - Entity beans have been replaced by JPA. 16
- 17. 2. Java Servlet Technology 2.5 - Extends the capability of servers - Commonly used to extend applications hosted by Web servers 3. Java Server Pages Technology 2.1 - Text document – HTML+WML+JSP elements - Construction of Dynamic content 17
- 18. 4. Java Server Pages Standard Tag Library 1.1 - JSTL - Provides standard set of JSP tags instead of mixing multiple tags by multiple vendors - iterator and Conditional tags – control flow in XML documents - Database access tags using SQL - Uses JSP container 18
- 19. 5. Java Server Faces 1.2 - Simplifies UI build process - server side UI building framework - Provides a set of reusable UIs from which new UIs cn be constructed. 6. Java Message Servics 1.1 - JMS - Componnts to send , receive and read Messages - Lossely coupled and Asynchronous. 19
- 20. 7.Java Transaction API1.1 - JTA – interface for transactions - default auto commit and rollbacks 8. Java mail 1.4 - email notifications - 2 types – application level interface & Service provider level interface - Java mail + service provider= Internet email 20
- 21. 9. JavaBeans Activation Framework1.1 - JAF - provides service for data identification access encapsulation operation identification JavaBean creation for identification 21
- 22. 10. Java API for XML processing1.4(JAXP) - Supports XML document processing using DOM,Simple API for XML, and Extensible style sheet Language Transformation(XSLT). 11. Java API for XML web services(JAX-WS) -provides web services 12. Java Architecture for XML binding(JAXB) - convienient bind between XML schema and Java language programs 22
- 23. 13. SOAP with attachments API (SAAJ) - Standard way to send XML documents over internet. 14. Streaming API for XML(StAX) - Alternative to DOM,Simple API for XML, TrAX . 15. Java API for XML registeries(JAXR) - provides access to business and general purpose regiters over web 23
- 24. 16. J2EE Connector Architecture - Provides solutions for connectivity between Application servers and EIS. 17. JDBC API - Supports SQL commands in Java programing language 18. Java Persistence API (JPA) - Uses ORM approach to bridge gap between Object oriented model and Relational database 24
- 25. 19. Java Naming and Directory Interface(JNDI) - provides naming and directory functionality - enables access to multiple naming and directory services 20. Java Authentication and Authorization(JAAS) - Authenticates and Authorizes users for JEE application. 25
- 26. Architecture of JEE 5 Client Tier Client M/c App HTML Client Pages JSP Web Tier JEE Server EJB EJB Business Tier EIS Tier Data BaSe Server Server 26
- 27. Java EE Containers • JEE provides services in the form of a container for every component • Containers are interfaces between components and Low level platform specific functionality • Components should be deployed in the container before use. 27
- 28. Container Types 1.EJB Container - provides an environment in which one or more Enterprise bean will run - Combination of classes and interfaces - Provides EJB component with lifecycle , state management , naming services, security mechanisms and persistence management. 28
- 29. 2. Web Container - Manages JSP and Servlet - Runtime environment for web application - Web container is always in a web server - provides context and lifecycle management 3. Application client Container - Manages execution of application client components. 4. Applet Conatainer - Manages the lifecycle of applets 29
- 30. Developing Java EE 5 Application Steps to develop a JEE application are 1. Develop application component 2. Compose application components into modules 3. Compose modules into application 4. Deploy application 30
- 31. Developing Application component - All the functional units (components) are designed in this phase - component – a class / collection of classes and interfaces - 5 types of components EJB,servlets, JSP , applets, application client, connectors. - 31
- 32. Compose application components into modules - process of bundling/wiring of components -3 types of modules can be designed 1. EJB module- -packaged and deployed as ejb-jar.xml - contains class files for ejbs,deployment descriptor - may contain classes and interfaces for ejbs not included in J2EE platform 32
- 33. 2. Web module- - Packaged and deployed in web.xml file - Contains class for servlets,JSP,Static documents , class for applet, web deployment descriptor. 3. Application client module - Packaged into jar files - Contains class for client, application client deployment descriptor 33
- 34. 3. Composition of modules into application - Java EE application is delivered as enterprise archive(ear) file. - JEE application packages the modules and their corresponding deployment descriptors. - application.xml is required as deployment descriptor of the entire application 34
- 35. JEE application (ear file) application.xml Ejb module Web module Java module Ejb module Web module Java module (jar) (jar) (jar) Ejb-jar.xml web.xml Application client.xml ejb jsp Java ejb servlet Java 35
- 36. 4. Application Deployment - Involves 2 steps 1. Installation of the application – the deployer copies the ear to the application server , generates additional container specific classes and interfaces 2. Configuration of the application- resolves all external dependencies and follow the application assembly instruction 36
- 37. Probable Architectures • Applet Client with JSP and Database presentation – Applet Business - JSP Database - JDBC • Application Client with EJB presentation – JFC/Console application Business - EJB Database - JDBC 37
- 38. • JSP Client with EJB presentation – Web Browser Web tier - JSP Business - EJB Database - JDBC • Web Services for application integration presentation – C# application Web tier - Web Services Business - EJB Database - JDBC 38