Post on 26-Mar-2015
JAVA EE - INTRODUCTION -
Pierre-Johan CHARTRE
pierre-johan.chartre@logica.com
Keywords
Java
JVM
ArrayList
JRE
JDK
J2SE
J2EE
Bytecode
JAR
Main class
Manifest.MF
.class
Javadoc
Object.class
debugger
UML
Object language
Reflection
Keywords
J2EEJSF
@EJBJMS
JPAValidation
CriteriaBuilder
JPQL NativeQuery
Renderer
@MessageDrivenBean
@PersistenceContext
@Inject
@SessionScope
@ManagedBean
@NotNull
Transaction
@TransactionAttributecomponent
@Converter
@ValidatorEntityManager
@Resource
@Stateless
container
JCP JSR
Java
• Java - A technology invented by Sun Microsystem (RIP) and now an Oracle product.• « Write once, run everywhere ».
• JVM – Java Virtual Machine. It abstracts your OS and executes the Java byte code.
•
Java• JRE – Java Runtime Environment . Set of tools aims to execute a
Java program• The virtual machine • The byte code interpreter and converter into native code • The standard Java API
• JDK – Java Standard Development Kit. It’s your toolbox. It allows to write Java source code and compiles it into byte code. • Javac, the java compiler which converts source code (.java) into byte code
(.class) • Jar, the java archiver. It archives a set of class files into a jar file • Javadoc, the documentation generator (abuse it!) • Jdb, the java debugger • A JRE
Java 2 SE• Java Standard Edition. Contains the basics API. It’s
desktop computer oriented. • A set of basics API
• Example: Collections
Java 2 EE• Specifications of standard API
• Different implementation of same API• Example: JPA is implemented by Eclipselink, OpenJPA, Hibernate
• Defined by the Java Community Process (JCP)• Certifications• Architecture pattern
• Large scale• Multi-tiers (Presentation Logic, Business Logic, Persistence)• Scalable• Reliable• Secure
• J2EE = an extension of Java SE to facilitate the development of enterprise applications ?
J2EE architecture
J2EE servers
• ‘’Java EE is a set of specifications implemented by different containers. Containers are Java EE runtime environment that provides certain services to the component they host… ’’
Antonio Goncalves, Beginning Java EE 6 Platform with GlassFish 3
• J2EE server = Web container + J2EE implementation
Runtime Web container
J2EE4
certified
J2EE5
certified
J2EE6
certified
Tomcat Yes
Open EJB Yes Yes
Geronimo = Tomcat + Open EJB
Yes Yes Yes
JBoss AS Yes Yes Yes Yes
IBM Websphere AS Yes Yes Yes Yes >=WAS 8
Glassfish Open source Yes Yes Yes
Oracle Glassfish Yes
Apache TomEE Yes Yes
J2EE APIs• javax.enterprise.inject.*• javax.enterprise.context.*• javax.validation.*• javax.persistence.*• javax.transaction.*• javax.ejb.*• javax.jms.*• javax.resources.*• javax.servlet.* • javax.faces.*• javax.faces.component.*
J2EE APIs – The big picture
Core J2EE Patterns• = J2EE architecture
Design Pattern
To sum up
• J2EE extends J2SE• J2EE is multi-tiers/layered• J2EE is a set of specifications, not a set of implementations
• J2EE server = container + J2EE implementations• A J2EE server host J2EE applications
•