Datasheet

Chapter 1

J2EE API Description

Java Transaction API (JTA) JTA enables a web application to gracefully handle

failures in one or more of its components by

establishing transactions. During a transaction,

multiple events can occur, and if any one of them

fails, the state of the application can be rolled back

to how it was before the transaction began. This

technology provides the robustness of relational

database transactional technology across an entire

distributed application.

CORBA CORBA technology in Java enables J2EE web

applications to communicate with distributed

components written in other languages that support

the language-independent CORBA standard.

JDBC

JDBC enables Java programs to communicate with

relational databases.

Connector

The Connector API enables Java programs to create

an abstraction layer for connecting with legacy

systems that don't implement other J2EE-supported

technologies.

JavaMail JavaMail provides the ability to send and receive e-

mail via the industry standard POP/SMTP/IMAP

protocols.

Java XML Parser (JAXP) JAXP gives J2EE applications the ability to

speak XML.

Note that the J2EE APIs are not designed to help developers write their own server software. Rather,

they are to designed to work with a special kind of server, called a J2EE application server (app server).

J2EE app servers are available on many operating systems, including Windows, Linux, Solaris, and Mac

OS X. To be considered an official J2EE app server, the app server vendor must show that the app

server complies with the J2EE standards and then purchase a J2EE license. Such vendors are referred to

as J2EE licensees.

Agree On Standards, Compete On Implementation

If developers follow the J2EE standards, they can use a compliant, licensed J2EE app server from any

vendor and it is guaranteed to work with their application. This flexibility is intended to help companies

avoid vendor lock-in problems, and thus they can enjoy the benefits of a competitive marketplace. The

Java slogan along these lines is "Agree on standards, compete on implementation," meaning that the

vendors all cooperate on establishing universal J2EE standards and then work hard to create the best

app server that supports those standards.