user manual

Chapter 26: VisiConnect overview 273
System Contracts
A Resource Adapter is a system-level driver specific to an EIS, which provides
access to that EIS. To put it simply, a Resource Adapter is analogous to a
JDBC driver. The interface between a Resource Adapter and the EIS is
specific to the EIS. It can be either a Java interface or a native interface.
The Connectors consists of three main components:
■
System Contracts that provide the integration between the Resource
Adapter and the application server (Borland Enterprise Server).
■
Common Client Interface that provides a standard client API for Java
applications, frameworks, and development tools to interact with the
Resource Adapter.
■
Packaging and Deployment that provides the capacity for various
Resource Adapters to plug into J2EE applications in a modular manner.
The following diagram illustrates the Connectors architecture:
A Resource Adapter and its collateral serve as the Connector. VisiConnect
supports Resource Adapters developed by EIS vendors and third-party
application developers written to the Connectors 1.0 standard. Resource
Adapters contain the components - Java, and if necessary, native code -
required to interact with the specific EIS.
System Contracts
The Connectors specification defines a set of system level contracts between
the application server and an EIS-specific Resource Adapter. This
collaboration keeps all system-level mechanism transparent from the
application components. Thus, the application component provider focuses on
the development of business and presentation logic, and need not delve into