TCP/IP HL7 V2 Adapter Collaborations

This section describes the inbound Collaboration (jcdHL7Inbound) and the outbound Collaboration (jcdHL7Outbound), provided within the standard sample Projects for inbound and outbound HL7 V2 messaging. These Collaborations are designed to work as is for HL7 V2 compliant interfaces, and can be configured for your specific needs using only the property configuration files. If an interface requires special functionality, the Collaboration's Java code is easily accessible for modification, much of which can be created graphically using the Collaboration Editor's Business Rules Designer.

The Collaborations contain a number of Message Libraries that extend functionality for HL7 V2 message handling, logging, error messaging, journaling, and sequence numbering. These include both generic HL7 Message Libraries for HL7 ACK/NAK generation or verification, and the Resource Adapter that communicates to the external system and offers services to the application server. The Collaborations control messaging protocol and all business logic.

The Collaborations are designed to target one unit of work at a time, meaning the resolution of one message at a time. The basic structure of both Collaborations is a state machine implemented in a Java switch statement. The state machine keeps track of the messaging protocol so when a Collaboration is invoked, it can retrieve the state of the connection just handed to it by the RA, and then execute the proper actions based on the state machine.

At the end of each action, the state is set for the next execution of the Collaboration. There are three main states:

• To Establish: A new or reset connection needs to have an HL7 session established. If sequence numbering is used, the sequence numbers need to be negotiated.

• Messaging: This is where the exchange of messages and ACKs takes place.

• Shutdown: This is where any cleanup can happen before the connection is closed, or to close the connection.

Additional Collaborations can be added to a Project to increase message flow.

The TCP/IP HL7 V2 inbound Collaboration publishes received data as a Byte message in JMS using the sendBytes() method. However, the HL7 V2 outbound Collaboration expects a Text message from JMS. The adapter is not designed for the HL7 V2 outbound Collaboration to subscribe to a JMS data queue created by the HL7 V2 inbound Collaboration directly. HL7 V2 inbound and outbound Collaborations are designed to communicate through an HL7 V2 TCP/IP adapter connection.