Overview of J2EE
Enterprise APIs were packaged together as Java 2, Enterprise Edition
The standard JDK (javac, java, etc.) was called Java 2, Standard Edition
J2EE includes the entire set of APIs, but may be used in smaller pieces.
In order to be J2EE certified, a server must pass Sun's
Compatibility Test Suite
Goals of J2EE
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Highly Available
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Secure
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Reliable and Scalable
Sun provides the standard (Platform), the Compatibility Test Suite,
a Reference Implementation (RI), and the J2EE BluePrints, a set of
best practices
J2EE components are also provided by a wide variety of vendors, including
IBM, BEA, Sun, Novell, Oracle, Macromedia, and others.
APIs
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Java Servlets - a simple, consistent mechanism for
extending the functionality of a web server.
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JavaServer Pages (JSP) - a simplified, fast way to create
dynamic web content that is server and platform independent.
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Enterprise JavaBeans Architecture (EJB) - create, deploy and manage
cross-platform, component-based enterprise applications
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JDBC - a uniform interface to a wide range of relational databases.
Comes in two parts, the application level interfac (required) and
the service provider interface to attach a JDBC driver to the J2EE
platform.
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JavaMail a platform independent and protocol independent framework to
build Java-based mail and messaging applications.
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Java Naming and Directory Interface (JNDI) - allows unified access to
multiple naming and directory services across the enterprise.
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Java Message Service (JMS) - a standard Java API for reliable
enterprise messaging services. (point-to-point and publish/subscribe)
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Java Transaction API (JTA) - a high-level transaction management
specification intended for resource managers and transactional
applications in distributed transaction systems.
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Java Transaction Service (JTS) - provides open, standard access
to transaction resources.
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Java Interface Definition Language (IDL) - provides interoperability
with CORBA, the industry standard for heterogeneous computing.
Java programs may invoke external CORBA objects.
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RMI-IIOP - an implementation of the Java RMI API over the
OMG's industry-standard Internet Inter-Orb Protocol (IIOP). Clients
of EJBs are required to use the RMI-IIOP APIs, and containers
are required to allow EJBs to be accessed using IIOP. This allows
EJBs to be protocol independent, and interoperable among containers.
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J2EE Connector - a standard architecture for connecting the
J2EE platform to heterogeneous Enterprise Information Systems.
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JavaBeans Activation Framework (JAF) - provides a framework
for handling data in different MIME types
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Java API for XML Parsing (JAXP) - provides support for both SAX
and DOM parsing of XML documents and XSLT transform engines.
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J2EE Connector Architecture - A J2EE Service Provider Interface (SPI)
that allows Enterprise Information Systems to be plugged into
any J2EE product.
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Java Authentication and Authorization Services (JAAS) - allows
services to authenticate and enforce access control for users
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Web Services, Java API for XML Remote Procedure CALL (JAX-RPC)
uses SOAP/HTTP for RPC. Soap Attachments API for Java (SAAJ) allows
low level messages. Java API for XML Registries (JAXR) provides
client access to XML registry servers.
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Java Management Extensions (JMX) - a special management enterprise
bean to provide standard management of J2EE servers and services.
The J2EE architecture:
(From Sun's J2EE specification v 1.4)
