Overview j2ee6

8/13/2019 Overview j2ee6

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What's New withJava EE 6?

Agenda Java EE 6 Overview

Servlet 3.0

JavaServer Faces 2.0

EJB 3.1

Web Beans 1.0 (formly) JSR-299

Overall goal for Java EE 6

Make the platform

Easier to use, Easier to learn. Easier ExtensibilityMore ways to integrate frameworks.

Easier to EvolveThe size and wideness of the Java EE has made itdifficult to evolve. Profiles and Pruning should take care of that.

SOABetter support for SOA is also defired as a goal of the newspec.


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Java SE 6 Timeline

Java EE 6 Timeline

Java EE: Past & Present


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Major new features Profiles

Pruning

Extensibility Ease of development.

Profiles

Profiles are targeted bundles of technologies

(Simple) rules set by platform spec.

Profiles can be subsets, super sets or overlapping.

Decoupling of specs to allow more combinations

Two profiles available:

Full profile (including all technologies)

Web profile (including a subset of technologies)

Web Profile Much discussion in the expert group and outside it

Latest proposal: a fully functional mid-sized profile

Accepted:

Servlet 3.0, JSP 2.1, JSR-45 (Debugging), EL 1.2, JSTL 1.2,

JSF 2.0

EJB Lite 3.1, JTA 1.1, JPA 2.0, JSR-250 (Annotations)

Controversial:

JAX-RS 1.1, Web Beans 1.0, JSR-303 Bean Validation


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Pruning Make some technologies optional

A component marked pruned at the current version may

become optional in the next version. Pruned technologies will be marked in the javadocs.

Current Pruning list:

JAX-RPCReplaced by JAX-WS

EJB Entity BeanReplaced by JPA

JAXRAPI for XML Registr ies, never widely adopted.

JSR 88Deployment API, never widely adopted

Extensibility Embrace open source libraries and frameworks.

Zero-configuration, drag-and-drop for web frameworks.

Servlet, servlet filters, context listeners for a framework getdiscovered and registered automatically.

Completely general solution using web fragments.

Scripting languages can use the same mechanism.

Ease of development Ongoing concern

This time focus is the web tier Lots of opportunities in other areas, e.g. EJB

General principles:

Annotation-based programming model.

Traditional API for advanced users

Reduce or eliminate need for deployment descriptors

Get technologies to work together well.


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Ease of development (cont.)

Proposed components(1)Full JSRs

EJB 3.1(JSR-318)

JPA 2.0 (JSR-317)

Servlet 3.0 (JSR-315)

JSF 2.0 (JSR-314)

JAX-RS 1.0 (JSR-311)

Connectors 1.6 (JSR-322)

Web Beans 1.0 (JSR-299)

Bean Validation 1.0 (JSR-303)

Proposed components(2)

Maintenance Releases

JAXB 2.2 JAX-WS 2.2

JAX-RS 1.1

EL 1.2

JSP 2.2

Others

Authentication SPI (JSR-196)

Concurrency utilities for Java EE (JSR-236)


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Servlet 3 0

Servlet 3.0 highlight Annotation-based programming model

@WebServlet, @ServletFilter, etc.

Modular web.xml descriptor:

WEB-INF/lib/mylibrary.jar

META-INF/web-fragment.xml

Annotations and web fragments are merged.

Programmatic API for dynamic registration of servlets.

Servlet 3.0 async API Useful for Comet, chat rooms, long waits.

Must declare @ WebServlet(asyncSupported=true) The call:

AsyncContext ctx=ServletRequest.startAsync(req,res);

AsyncContext can then either:

dispatch(String path)

start(Runnable action)

Must be paired with

Complete()


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JavaServer Faces 2 0

JavaServer Faces 2.0 HighlightsTop Five Goals:

Make custom components much easier to develop

Ajax support

Page description language (PDL)

Reduce the configuration burden

Provide for better compatibility between JSF component

libraries from different vendors

Ingredients of a JavaServer FacesComponent+Ajax solution Resource Delivery Mechanism

Partial Tree Traversal Partial Page Update

Ajaxification Capability

Ajax Enabled Components

In JSF 2.0 Spec

In Component Library


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EJB 3 1

EJB 3.1 Highlights Ease-of-use improvements

No-interface view

Once source file per bean

EJB inside web applications

No ejb-jar

Use WEB-INF/classes

Shared component environment

Portable JNDI

EJB 3.1 Highlights (cont.) Singleton beans: @Singleton

Shared state One instance per bean per JVM

Container/Bean managed security@ConcurrencyManagement

Lightweight asynchronicity

Async business methods@Asynchronous

Methods must return void or Future


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EJB 3.1 Highlights (cont.)

Enhanced EJB Timer Service

Cron-like scheduling

Initialization-time timer creation

@Schedule(dayOfWeek=Mon/Wed)

Embeddable EJB Container

Use in JavaSE environments

Bootstrapping API

EJBContainer

EJB 3.1 Lite Session beans (stateless, stateful, singletons)

Transactions

Security

Interceptors

Ejb-jar.xml

Embeddable container API: EJBContainer

OK to bootstrap on Java SE

Beans looked up by global JNDI name

EJB 3.1 lite vs EJB 3.1 full EJB 3.1 lite => Java EE 6 web profile

EJB 3.1 full => Java EE 6 full profile


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Additional Features Java Persistence Architecture 2.0

Improve object/relational mapping

Java Contexts & Dependency Injection (AKA - Web

Beans)

Java Server Faces 2.0

AJAX

Simplified component creation

JAX-RS 1.1RESTful services

Web Beans 1.0 Adds contextual services to the platform

Unifies JSF managed-beans and EJB components

Dependency-injection

@LoggedIn User user;

Binding types to select among alternatives

Scopes (session, singleton, conversation,)

Deployment types to select fami lies of beans(e.g. mocks)

Programmatic API: Manager, Bean, Context,..

Summary Smaller, more agile platform: profiles, pruning, extensibility

Ease of development still a major focus area Component specs ready for public review

Open source implementation in GlassFishV3


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References

http://jcp.org/en/jsr/results?id=4821

http://jcp.org/en/jsr/results?id=4821

http://weblogs.java.net/blog/robc/

https://glassfish.dev.java.net/

http://blogs.sun.com/theaquarium

http://wiki.glassfish.java.nethttp://jcp.org/en/jsr/results?id

=4821

Overview j2ee6

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