Patterns: Implementing Self-Service in an SOA Environment

Chapter 6. Technology options 127

6.3.10 Additional enterprise Java APIs

The J2EE specification defines a set of related APIs that work together. Here are

the remainder not discussed so far:

򐂰 JNDI: Java Naming and Directory Interface™

This package provides a common API to a directory service independent of

any directory access protocol. This allows for easy migration to new directory

services. Through this interface, component providers can store and retrieve

Java object instances by name. Service provider implementations include

those for JDBC data sources, LDAP directories, RMI, and CORBA object

registries. Sample uses of JNDI include:

– Accessing a user profile from an LDAP directory

– Locating and accessing an EJB home

– Locating a driver-specific data source

򐂰 RMI-IIOP: Remote Method Invocation (RMI) and RMI over IIOP

These methods are part of the EJB specification as the access method for

clients to access EJB services. From the component provider point of view,

these calls are local. The EJB container takes care of calling the remote

methods and receiving the response. To use this API, component providers

create an IDL description of the EJB interface and then compile it to generate

the client-side and server-side stubs. The stubs connect the object

implementations with the Object Request Broker (ORB). ORBs communicate

with each other through the Internet Inter-ORB Protocol (IIOP). RMI can also

be used to implement limited-function Java servers.

򐂰 JTA: Java Transaction API

This Java API for working with transaction services is based on the XA

standard. With the availability of EJB servers, you are less likely to use this

API directly.

򐂰 JAF: JavaBeans Activation Framework

This API is not intended for typical application use, but it is required by the

JavaMail™ API.

򐂰 JavaMail

This is a set of classes for supporting e-mail. Functionally it provides APIs for

reading, sending, and composing Internet mail. This API models a mail

delivery system and requires the SMTP for sending mail and POP3 or IMAP

for receiving mail. Special data wrapper classes are provided to view and edit

data in the mail content. Support for MIME data is delegated to the JAF-aware

beans.

򐂰 JAXP is an API for parsing and transforming XML documents.

򐂰 JAAS is the Java Authentication and Authorization Service.