260

Container 

component

contracts

Application 

Container

Component

Connection

pool manager

Transaction

Application

manager

contract

Security

Message

System

service manager

pluggability

contracts

Resource

manager

Adapter

Lifecycle

Work

manager

manager

EIS specific

interface

Enterprise

J2EE Application Server

Information

System

Figure 6.3

Connector Architecture System and Contracts

The earlier version of the Connector architecture focused on synchronous

integration with EISs, while the current version that is part of J2EE 1.4 extends

this core functionality to support asynchronous integration. That is, it supports

both outbound and inbound message driven integration that is protocol

independent.

A 

resource adapter

 is a J2EE component that implements the Connector API

for a specific EIS. Communication between a J2EE application and an EIS occurs

through this resource adapter. In a sense, think of a resource adapter as analogous

to a JDBC driver, since it provides a standard API for access between the J2EE

server and the external resource. 

The J2EE Connector architecture, through its contracts, establishes a set of

rules for EIS integration. The J2EE application server and an EIS resource adapter

collaborate, through a set of system level contracts, to keep security, transaction,

and connection mechanisms transparent to the application components. Applica 

tion components and resource adapters rely on the application level contract for

their communication.