Module 1 Enterprise Java Technologies

Enterprise Java Technologies Topics to be Covered: Environment & Architecture Java EE Platform Specification Java EE Technologies

Enterprise Java Technologies Environment & Architecture

Java Environments Four Major Types of Java Environments –Work Station/Desktop/Server –Personal Java -> CDC (Connected Device Configuration) –Java SE for Embedded –Java Card

Platform Editions Three platform editions –Standard Edition (Java SE) –Enterprise Edition (Java EE) –Micro Edition (Java ME)

Evolution of Java OakJava 1.02 Java 2 SDK, v.1.2, 1.3, … Java 1.1 Embedded JavaPersonal Java Java SEJava EEJava ME CDCCLDC MIDP

Java Technologies and Resources “ The source for Java technology” – Technology Overviews – Java SE erview/index.html – Java EE erview/index.html – Java ME verview/index.html

Object-Oriented Language Small Talk Single inheritance Easy-to-Compile Pascal Semi-compilation C++ Lessons Learned Java

The Java Package Class Methods Properties Package java.awt.*

The Java Package Packages map to the directory structure of host system. Java classes are found using a fully referenced class name –java.lang.Object –com.xyz.net.Socket

The Java Package Socket Root Directory com xyz net Socket

Java’s Key Packages Package NameDescription java.appletApplet classes java.awtHeavyweight GUI classes java.beansJavaBeans support API java.ioInput/Output classes java.langJava Core classes java.mathArbitrary Precision arithmetic java.netNetworking classes java.rmiRemote method invocation java.sqlJDBC classes java.utilUtility classes javax.swingLightweight GUI classes

Definition of Java From The Java Language: A White Paper –Java: A simple, object-oriented, distributed, interpreted, robust, secure, architecture neutral, portable, high performance, multithreaded, network-ready and dynamic language

Definition of Java From The Java Language: A White Paper –Java credo: “Write Once – Run Anywhere” –Java goals: Platform independent, extensible, easy-to-program language that takes advantage of the inherent distributed infrastructure of the Internet.

Portable and Platform Independent ‘Write Once, Run Anywhere” depends on: –A processor or code engine –A uniform run-time environment

Portable and Platform Independent The Java Virtual Machine –Guarantees programs run the same on all platforms –Standardizes data type size –Has stack-based architecture –Is an emulator

Portable and Platform Independent The Java Runtime Environment –Shields platform specific issues –Establishes security mechanism –Loads required classes –Compatibility requirements

Portable and Platform Independent Native OS Java Support Classes JVM Executable Java Runtime Environment

Platform Independent –Bytecode Java sourceBytecode DevelopmentDeployment compiler JRE JVM

Three-Tier Architecture Data management –handles data storage Business logic –implements business rules User presentation –format and Display

Three-Tier architecture The Enterprise User Interface Logic Data Management MotifWindows Telephony Business Rules Business Rules Business Rules Data Service Data Service Data Service

Three-Tier Architecture Advantages –business rules treated as assets –thin client –business logic can be shared –reusable parts –solution for Web-based applications

Web Platform Solution Web application adheres to three-tiered model –user presentation web browser and web server –business logic application server –data management enterprise information system

Web Platform Solution

Java Application Server Presentation & Business Logic Servlet/JSP EJBs, RMI Objects JDBC Internet Browser Web Server

Enterprise Java Technologies Java EE Platform Specification

Java EE Platform Specification Provides all Java SE APIs Requires additional optional packages or standard extensions Four containers supported –application client containers –applet containers –web containers –enterprise bean containers

Application Components Applet Container Applet Java SE Application Client Container Application Client Java SE JDBC JAXP JAAS JMS Database Web Container JSPServlet JMS JAXP JAAS JTA Java Mail JCA JDBC Java SE EJB Container EJB JMS JAXP JAAS JTA Java Mail JCA JDBC Java SE HTTP SSL

Application Components Component Types –Application Client –Applets –Web Components Servlets JSP –Enterprise JavaBeans

Server Support for Application Components Server Support –Complete Dependence Deployment, Management, & Execution – Web Components – EJBs –Partial Dependence Deployment and Management on Server Loaded to and Executed on Client – Applets –Dependence not clearly defined –Application Components

Containers Runtime Support Gateway to Java EE APIs Mediates communication between different application components Transparently provides configuration management through deployment descriptor settings Must provide a Java Compatible Runtime Environment

Java EE Objectives Integrated support for web components and enterprise beans Common naming context (JNDI ENC) Declare resources using XML deployment descriptor JAR packaging technology –.war (Web Archive) –.ear (Enterprise Archive) Access to a common transaction object

Java EE Software Standards Java Database Connectivity (JDBC) –database connectivity Java Remote Method Invocation (RMI) –remote object communications RMI-IIOP RMI-JRMP Java Naming and Directory Interface (JNDI) –naming locator for remote objects Java Transaction API (JTA) –transaction support

Java EE Software Standards Java Message Service (JMS) –message-oriented middleware services HTTP and HTTPS Servlets –server-side request-reply component JavaServer Pages (JSP) –Java embedded in a Web page Java API for XML Parsing (JAXP) Java Connector Architecture (JCA)

Java EE Software Standards Enterprise JavaBeans Architecture (EJB) –Session stateless stateful –Entity Java Persistence API container-managed –Message-driven invoked by a JMS message

Enterprise Java Technologies Java EE Technologies

Java Servlets – Static Content REQUEST REPLY

Java Servlets – Dynamic Content REQUEST REPLY “On the Fly”

Java Servlets Enhances server capability –Perform calculation –Access DBs Component which implements javax.servlet.Servlet interface Managed and invoked by Java EE Servlet container Containers provide session management Incorporate JavaBean components

JavaServer Pages (JSPs) Dynamically generate web content HTML-based text documents with sections of Java code (scriptlets) embedded Servlet generated from JSP on first access Web designers create and manipulate HTML, XML, etc. parts of the page Java developers create and manipulate Java code

JavaServer Pages (JSPs) JSP REQUEST GENERATE HTML JSP 1st REQUEST COMPILE TO SERVLET 10011… … … HTML ALL SUBSEQUENT REQUESTS SERVLET

JavaServer Faces (JSF) Provides a component-based API to build a robust, rich server-side user interface for web applications –HTML: Good set of user interface components –Applets: Better set, but must be downloaded and executed on client –Developer time spent retrieving and validating request parameters, and passing parameters to business logic

JavaServer Faces (JSF) JSF components handle all the complexity of managing the user interface –Developer can focus on business logic –JSF components do not directly generate specific presentation code Custom renderers create client presentation code –JSF components connect to application data sources –JSF connects client-generated events to event handlers on the server

Java Database Connectivity (JDBC) Connect web applications with back-end data sources Common API works with various DBs through a system-specific driver

Enterprise JavaBeans Entity Beans –Model Business Concepts customer piece of equipment an item in inventory Session Beans –Models Business Processes stock market purchase hotel reservation

Enterprise JavaBeans Message-driven Beans –Models Business Processes –Similar in purpose to session beans coordinates tasks receives messages asynchronously

Web Services Endpoints the provide web applications with server-side business rules From World Wide Web Consortium (W3C): A Web service is a software system design to support interoperable machine-to-machine interaction over a network. It has an interface described in a machine-processable format (specifically WSDL). Other systems interact with the Web service in a manner prescribed by its description using SOAP message, typically conveyed using HTTP with an XML serialization in conjunction with other Web-related standards.

Web Services JAXR API (Java API for XML Registries) –Accesses WSDL definitions published by XML Registries JAX-RPC API (Java API for XML-based Remote Procedure Calls) –Allows client application to invoke a Web Service Java EE architecture supports a component model for easily deploying web services (JAX- WS)

Transaction Support and Security Transactions –Set of activities that will collectively succeed or fail –EJB container provides built-in support for managing transactions Security –Authentication –Authorization User roles

Enterprise Java Technologies Topics Covered: Environment & Architecture Java EE Platform Specification Java EE Technologies