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A Brief Introduction to JavaEnterprise Edition Platform(JEE)

Juan Manuel GimenoJosep Maria Rib

{jmgimeno,josepma}@diei.udl.cat

Title:(by-sa.eps)

Creator:Adobe Illustra

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Wat do !e mean b" Platform#

Wen a pro$rammer as to andle collections

%oesn&t start b" developin$ a as table

'ses te ollections API in te tandard Edition of

Java (JE) Wen a pro$rammer needs a transactional*

secure* interoperable* distributed application

%oesn&t start b" developin$ te lo!+level plumbin$ 'ses te Enterprise Edition of Java (JEE)

,ocuses te efforts in te problem not in te lo!+level details

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A little bit of istor"

JEE !as born in Ma" -../ as Pro0ect JPE(Java Professional Edition)

J1EE-21 !as released in %ec -... as an

umbrella specificationconsistin$ on -3 JRs(Java pecification Re4uest)

tartin$ !it J1EE-25 te specification !asdeveloped b" te Java ommunit" Process(JP)

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J1EE-21

,ocus on distributed s"stems

6RBA !as te competitor

Enterprise Java Beans (EJBs)

Remote stateful and stateless service ob0ects

Entit" EJBs (persistence ob0ects) optional

Built on Remote Metod Invocation+Internet Inter

6RB Protocol (RMI+II6P) ervlets and Java erver Pa$es (JP)

JM for messa$in$

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J1EE-25

,irst to be developed b" te Java ommunit"Process (JP) under JR7/

Entit" beans no! are mandator"

8M9 deplo"ment descriptors for EJBs

Introduced local interfaces passin$ ar$umentsb" reference

J1EE onnector Arcitecture (JA) introducedto connect Java EE to EI (EnterpriseInformation "stems)

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J1EE-2:

JR -7-

Added support for Web ervices as EJB12-could be invo;ed over 6AP>P

>imer service created

Better support for

Mana$ement

%eplo"ment

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But tere !ere problems 222

"stems created !it J1EE

>oo complicated

%evelopment time out of proportion

J1EE component model

=eav"+!ei$t

%ifficult to test

%ifficult to deplo" %ifficult to run

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? and alternatives

A ne! !a" o$ developin$ enterpriseapplications usin$ li$t!ei$t frame!or;s

truts

prin$ =ibernate

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Java EE 7

JR 1::

Inspired in open source frame!or;s

Based on a P6J6 (Plain 6ld Java 6b0ect)

pro$rammin$ model

Metadata can be defined b" annotations and8M9 descriptors optional

Java erver ,aces (J,) introduced JA8+W 123 replaced JA8+RP as te 6AP

!eb services API2

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Java EE @

JR 5-@

Annotations* P6J6 pro$rammin$*confi$uration+b"+eception (even for !eb tier)

JPA 123

e! JA8+R -2- (RE>full !eb services)

%eprecation of some APIs (b" prunnin$)

ProfilesC !eb profile

%ependenc" in0ection

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=istor" of te pecification

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Java ommunit" Process (JP)

6pen or$aniDation created in -../ involved inte definition of te future versions and features

Wen te need for a ne! component or API is

identified* te spec lead creates a JR andforms a $roup of eperts

>is $roup as to deliver

A specification A reference implementation (RI)

A >ecnolo$" ompatibilit" it (>)2

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tandards

Java EE is an umbrella specification tatbundles to$eter oter JRs

Java EE standards implemented b"

ommercial () or open+source solutions

o loc;in$ to an implementation

Portable !it minor can$es

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Arcitecture

Java EE is a set of specifications implementedb" diferent containers

ontainers are runtimeenvironments tat

provide certain servicesto te componentste" ost

>e components use !ell+defined contractstocommunicate

!it te Java EE infrastructure

Wit oter components

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Relationsips bet!een containers

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omponents

>e 0ava EE runtime defines four t"pes ofcomponents tat an implementation mustsupport

Application clients and applets are components tatrun on te client

Java ervlets* JP and J, are components tatrun on te server (!eb container)

Enterprise Java Beans EJB are businesscomponents tat run on te server (e0b container)

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ontainers

>e Java EE erver provides underl"in$services in te form of a container for ever"component t"pe

Eac container as a specific role* supports aset of APIs and offer services to components

ecurit"* database access* transaction andlin$*namin$ director"* resource in0ection* ?

Because all tese services are provided* tepro$rammer can concentrate on te businessproblem at and

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lients and servers

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ervices provided b" containers

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Biblio$rap"

A2GonFalves* Be$innin$ Java EE@ Platform!it Glassfis 5H* Apress (133.)

>e Java EE @ >utorial* olume I

http://java.sun.com/javaee/6/docs/tutorial/doc/http://java.sun.com/javaee/6/docs/tutorial/doc/