Where can I find information about interfacing with JMS Queues

Hi-

I have searched through documentation, etc and see many mentions of using Ensemble / Health Connect along with the Java Gateway to interface with JMS Queues, but see no specific documentation on how to do this.

Does anyone have any information, or a concise example of using the Java Gateway to allow Ensemble / Health Connect to be able to place messages and retrieve messages from a JMS Queue?

Thanks

 

Answers

The high-level steps are:

  1. Create a Java class using the APIs provided by your JMS server (ActiveMQ, RabbitMQ, etc.) and create a JAR file. JMS is a standardized API, not a protocol, so there is not one universal JMS client that will work with all JMS servers.
  2. Use the Java Gateway wizard to generate COS proxy classes for your Java class
  3. Setup a Java Gateway Service in your production. Make sure it points to your custom JAR file and the JAR file provided by the JMS server vendor.
  4. Create a custom business service or operation that calls the COS proxy class methods.
  5. When adding the service or operation to the production, configure it to point to the Java Gateway Service and use the correct Java class

For a Business Operation, you'll just use the usual approach: the message map points to a custom method. The custom method then calls the COS proxy class methods for your Java class. The BO class should extend Ens.BusinessOperation and use the adapter EnsLib.JavaGateway.OutboundAdapter.

For a Business Service, there's an out of the box adapter, EnsLib.JavaGateway.InboundAdapter. You just need to create a custom Operation that extends Ens.Business service and uses EnsLib.JavaGateway.InboundAdapter as it's adapter. This is quite nice, because EnsLib.JavaGateway.InboundAdapter handles most everything automatically. Your Java class just needs to implement a set of methods defined by the Inbound Adapter. See the class reference for EnsLib.JavaGateway.InboundAdapter for more details:
 *             .Connect(pJGClientConnectSpec,pTimeout,pInbound)
 *             .Disconnect(pInbound)
 *             .IsConnected(pInbound)
 *             .getErrorText() [returns empty string if no error on previous method call]
 *             .ReceiveMessage(pTimeout) [inbound only; pMsgIn return needs not be populated if timed out]
 *             .SendResponse(pMsgOut) [inbound only, optional-needed if OnProcessInput will return an object]
 *             .SendMessage(pMsgOut,pGetReply,pResponseTimeout) [outbound only; pMsgIn return needs not be populated if no responses are anticipated]

I've created some sample code including a production and Java classes. It includes a generic class that implements most of the necessary methods using standard JMS API methods and provides an ActiveMQ-specific subclass that uses the ActiveMQ proprietary methods to initiate the connection.

As always, this is sample code for demonstration purposes only and is not production ready.