You may wish to connect your service-oriented architecture (SOA) application to an existing MQ JMS or 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 MQ JMS or 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 MQ 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 MQ JMS binding by selecting the import and from the contextual menu select Generate Binding > Messaging Binding > MQ 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.
Select if you wish to Configure new messaging provider resources (the default) or Use pre-configured messaging provider resources. If you choose pre-configured, then add the JNDI names for the connection factory and the send destination for a one-way operation, and send and receive destinations for a request-response operation. We chose to configure the messaging resources. With the MQ JMS binding, you must specify the WebSphere MQ queue name for the send destination and receive destination (for request-response operations, which in our case we will be using). The WebSphere MQ queue manager must also be specified. The existing default queue manager is selected by default.
In the Security configuration section, the J2C Authentication Data Entry property lets you specify an authentication alias that should be configured on the server with a userid and password.
You must 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 serialization types provided as listed below. For serialization types beginning Simple JMS, you must have previously created the business objects required (see the Prerequisites section of Generating an MQ JMS import binding for a quick way of creating these business objects).
If the JMS client is expecting a different serialization style than those 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 Service Data Object (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.
Request or response | Connection factory | Send destination | Receive destination | Listener port | Correlation scheme |
---|---|---|---|---|---|
Configuration elements in a request or response | Creates the connection to the messaging provider. | Destination where the message is sent. | Destination where the response message is received. | Port that listens to the response from the WebSphere MQ server | Correlates response messages with request messages in request-response operations. |
Import request | A JNDI name or one created with default settings when the application is deployed. | A JNDI name or the queue name of the WebSphere MQ queue manager. | Not applicable | Not applicable | Adds a request ID to the request message (default) or adds a correlation ID to the request message. |
Import response | Uses the same connection factory as the request or one that is specified by you. | Not applicable | A JNDI name or the queue name of the WebSphere MQ queue manager. | A name is created on deployment or one that is specified by you. | Not applicable |
Select the End-point configuration tab under the Binding tab. Under the Request tab, you can accept the defaults and the tools will create a connection factory when the application is deployed or you can specify a connection factory JNDI name if it has been pre-configured on the messaging provider resource. In our case, we accepted the defaults.
We chose a BINDINGS transport option, which is the default.. With this setting, you do not need to specify host name, channel or port as WebSphere MQ JMS classes will use the Java Native Interface (JNI) to call directly into the existing queue manager API rather than communicating through a network. Bindings is a shared memory protocol and may offer better performance. An alternative is the CLIENT setting, which means you must specify the values for the client configuration including host name, channel and port and optionally the client channel definition table. The WebSphere MQ client connection is used to connect to the queue manager.
Expanding Send Destination Properties , you can specify a JNDI name or you can accept the defaults, in which case the tools create the properties. Specify the appropriate settings to ensure your SOA application is able to communicate to the JMS client. For this task, we accepted the defaults for the settings but provided the send destination, which was specified earlier when we created the bindings. The name contains the WebSphere MQ queue name.