The JCA SNA LU0 is a standard resource adapter that complies with J2EE Connector Architecture. It can be deployed to application server to enable the J2EE application components to communicate with remote Enterprise Information System (EIS) by SNA LU0 protocol.

The JCA SNA LU0 Connector enables you to deploy these applications into a managed environment in which a J2EE-capable application server such as WebSphere Application Server handles connection pooling, transactions, and security.

The JCA SNA LU0 Connector supports JCA 1.5 specification. In JCA 1.0, only outbound communication is supported. It means that when using the CCI API of JCA 1.0, the application sends message and waits for receiving the reply message synchronously. But in JCA1.5, together with EJB2.1 Message Driven Bean, it can handle the inbound unsolicited message from EIS asynchronously.

See the graphic below for the architecture of JCA SNA and Dummy LU0:

The JCA SNA LU0 Connector implements the system contract between the resource adaptor and the application server to support the JCA feature.

To communicate with remote host by SNA LU0 protocol, the SNA LU0 Connector calls the native API of the communication server by JNI which is implemented by the DLL Library file.

UNICOM^® Digital Transformation Toolkit (UDTT™) also provides a Dummy JCA LU0 Connector besides JCA LU0 Connector. When using the Dummy LU0 Connector, a dummy host emulator in the JCA Connector is responsible for replying and delivering message. There is no SNA communication between JCA adapter and the remote host by Communication Server. The send and reply message's content and format are defined in a response file. The Dummy LU0 Connector is mainly used for BTTSample or learning JCA SNA Connector. When the JCA SNA Dummy LU0 Connector is used, the Communication Server and DLL Library file are not needed.

The JCA SNA LU0 Connector supports both inbound and outbound communication. The outbound communication is implemented through CCI interface and the inbound communication is implemented by supporting the Message Inflow Contract, according to which, the inbound message is delivered from Connector to Message Driven Bean.

Besides the inbound communication support, JCA 1.5 also provides many other new features to make the inbound/outbound communication between J2EE application and EIS more reliable and more efficient. The JCA 1.5 new system contracts supported by Connector are Message Inflow Contract, Lifecycle Management Contract, Work Management Contract.