You may wish to connect your service-oriented architecture (SOA) application to an existing JMS client. In this task, we will take you step by step through the steps necessary to do this.
Prerequisite: The JMS administered objects are configured for the JMS Client and known. In addition, there should be a module that contains your service-oriented architecture application. The message format expected by the JMS client is also known
There are two main types of information that need to be captured by the JMS binding. One set of information is needed by the Service Component Architecture (SCA). This includes information such as the interface, which we discussed earlier, and the serialization type, which we will discuss later. The other set of information is the configuration needed to communicate using JMS such as the specification of JMS destination objects, which we will also discuss later.
Open the assembly editor of your module. From the import group on the palette, select an import and drag it on to the canvas. An import with no implementation and no interface is created. Right-click the component, select Add Interface from the contextual menu and add the interface created in step 1. Generate the JMS skeleton binding by selecting the import and from the contextual menu select Generate Binding > Messaging Binding > JMS Binding.
You may select the JMS messaging domain as either Publish-Subscribe or Point-to-Point. The consequences of selecting publish-subscribe is that the values for the JMS Destination type will default to use javax.jms.Topic. Similarly, the consequences of selecting point-to-point is that the values for the JMS Destination type will be default to use javax.jms.Queue. You may change these defaults within the wizard. If your interface contains a request-response operation, the wizard will default the JMS messaging domain to point-to-point.
You can also choose the serialization type that is expected by the JMS client application. The serialization type is used to map between the business object used in your SOA application and the message format expected by the JMS client application. There are several default serialization types provided. For serialization types beginning Simple JMS, you must have previously created the business objects required (see the Prerequisites section of Generating a JMS import binding for a quick way of creating these business objects).
If the JMS client is expecting a different serialization style other than the two above, select User Defined and specify the appropriate data binding implementation. An example of this different serialization would be if the JMS client is expecting a JavaBean as the payload of a JMS object message, then a user-supplied data binding implementation would be used that would map between the SDO and the JavaBean. See Creating a user-defined JMS data binding for an illustration on how this would be done.
For more information on JMS data bindings, see JMS and MQ JMS data bindings.
Lastly, you must specify if you wish to generate the TargetFunctionName message header property for the default function selector class. Checking this box causes a header property to be generated, which is expected by the default function selector implementation. If this is the desired behavior, keep it checked, otherwise uncheck the box. See JMS and MQ JMS function selector for more information.
In this task, the JMS client is expecting XML in a JMS text message so we chose the appropriate serialization type Business Object XML using JMS TextMessage. In addition, because you are communicating with an existing JMS client, you will uncheck the Generate "TargetFunctionName" message header property for default JMS Function Selector because the JMS client would not know how to handle the custom JMS header tag that would have been generated if it were checked.
Usage and configuration | Managed connection factory | Send destination | Receive destination | Callback destination |
---|---|---|---|---|
Usage | A factory used to create the connection to the messaging provider. | The destination where the message would be sent. | The destination where the response message would be received. This value is specified in the JMSReplyTo field of the sent message. | A destination used for internal purposes. |
Configuration | If your administrator provided an administered connection
factory object, use the JNDI name. If you do not use a JNDI name, a new connection factory will be created using the default settings when the SOA application is deployed. Your administrator should check that the connections resulting from this factory is appropriate to connect to the messaging provider. |
If your administrator provided an administered destination
object where messages should be sent to the JMS client, use the JNDI name. If you do not use a JNDI name, a new destination would be created when the SOA application is deployed and this would be used as the destination for the sent message. Your administrator should then pass this JNDI name to the JMS client. |
If your administrator provided an administered destination
object where messages should be received (if any), use the JNDI name. If you do not use a JNDI name, a new destination would be created when the SOA application is deployed and this would be used as the destination for the receive message (if any). Your administrator should then pass this JNDI name to the JMS client. Note: The SCA application will be listening
to messages on the Receive Destination using a specific correlation scheme.
The received message is expected to have the sent message's message id.
That is, the receive message needs to have its message header property JMSCorrelationID to
match the sent message header property JMSMessageID. The
JMS client must ensure that response messages it sends to the SOA application
have the message header property JMSCorrelationID specified
correctly, otherwise the SOA application will not receive the message.
|
You may specify a JNDI name of an existing administered
destination object for performance reasons. If you do not specify a JNDI name, a new destination would be created each time the SOA application is deployed. |
To specify the administered objects, select the Endpoint configuration tab under the Binding tab. Under the Connection tab, you can specify a bound connection factory class to connect to the WebSphere Process Server default JMS provider. You could also accept the defaults, in which case the tools would create a connection factory when the application is deployed on the server. Because the connection factory that would be created with the default settings is sufficient for this task, you will accept the defaults.
Under the JMS Destinations tab, you can specify the administered destination objects to send and receive messages or you can accept the defaults, in which case the tools would create them. Specify the appropriate settings to ensure your SOA application is able to communicate to the JMS client. For this task, the administrator provided JNDI names for the bound destination objects to send and receive a message to the existing JMS client and so you will specify the JNDI names for them. For the Send Destination Properties section, select the radio button Specify JNDI name for pre-configured messaging provider resource. Specify the JNDI name of the bound destination where you want to send your messages. Similarly, for the Receive Destination Properties section, select the radio button of Specify JNDI name for pre-configured messaging provider resource. Specify the JNDI name of the bound destination where you are to receive your messages.