IBM BPM, V8.0.1, All platforms > Authoring services in Integration Designer > Services and service-related functions > Access external services with messaging systems > WebSphere MQ Java Message Service (MQ JMS) > Create applications with MQ JMS bindings

Create an MQ JMS import to communicate with an MQ JMS or JMS client

You might want 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

For simplicity, we refer to an MQ JMS or JMS client as a JMS client.


Procedure

  1. For your SOA application to communicate to an existing MQ JMS or JMS client, first create a business object and an interface that would represent your JMS client application in an SOA manner. Mapping a message to an SCA interface provides guidance on how to create such a business object and interface.

  2. You must create a component that will enable your existing SOA application to communicate to the existing JMS client application. To do this, create an import and add a binding type of MQ JMS to it.

    There are two main types of information that must 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. Under Outbound Imports, select MQ JMS and drag it to the assembly editor. Select an interface or create one.

    Alternately, select Import under Component on the palette and drag it on to the canvas. An import with no implementation and no interface is created. Right-click the import, select Add Interface from the menu and add the interface created in step 1. Generate the MQ JMS binding by selecting the import and from the menu select Generate Binding > Messaging Binding > MQ JMS Binding.

  3. The Configure WebSphere MQ JMS Import Service window opens.

    You can 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 are that the values for the JMS Destination type will default to use javax.jms.Queue.

    You can change these defaults within the wizard. If your interface contains a request-response operation, the wizard defaults the JMS messaging domain to point-to-point.

    Select if you want 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. Also add the JNDI name for the activation specification (ActivationSpec class), which contains the configuration information for a message end point. 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.

    In the Data format section, select how the data will be serialized between the business object and the JMS message with a data binding. If you intend to use one of the default data bindings beginning Simple JMS, you must have previously created the business objects required (see the Prerequisites section).

    The data binding selection is discussed in JMS, MQ JMS and generic JMS bindings.

    In the Function selector section, if you do not want to use the TargetFunctionName message header property for the default JMS function selector class, clear it.

    The FunctionSelector class provides a valuable service at run time. It selects an operation to start on the component. The operation maps to a function to be performed based on the content of the JMS message.

    For example, the message might contain an employee record and be used to create, update, retrieve, or delete an employee record. The actual operation to invoke is determined from content in the header or body of the JMS message.

    In this task, the JMS client is expecting XML in a JMS text message so we chose the appropriate data format transformation, which is Serialized Java Object (JMS). In addition, because you are communicating with an existing JMS client, you will clear 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.

  4. The MQ JMS binding is created and shown in the properties view when the Binding tab is selected. The following chart provides some guidance for the configuration properties.

    Relationship of request and response to configuration
    Request or response Connection factory Send destination Receive destination Activation specification (ActivationSpec) 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. A class used to activate a message endpoint and associate it with a Message Driven Bean (MDB). 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 might 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.

  5. For the Receive Destination Properties section beneath the Response tab, we accepted the defaults but specified the receive destination, which we entered earlier when creating the binding. It contains the WebSphere MQ queue name. It lists the activation specification (ActivationSpec class) configuration properties.

  6. The existing JMS client might expect certain header properties to be configured. You can specify these under the Method bindings tab. For each business method that represents a corresponding JMS client application method, you can specify unique JMS message header properties required.

    For example, if the existing JMS client application requires the message header JMSType to specify the application method name for which the JMS message is targeted, you will specify it here.

  7. The Message Configuration tab shows the correlation scheme for the response message. Request Message ID to Correlation ID adds a request ID to the request message. It is expected that the reply copies the request ID to the correlation ID field of the response message so that the caller can correlate the reply message with the request message. Request Correlation ID to Correlation ID adds the correlation ID to the request message. It is expected that the reply copies the request correlation ID to the correlation ID field of the response message so that the caller can correlate the reply message with the request message.

  8. Selecting the Summary tab specifies the send and receive destination (in the case of a request-response operation) JNDI names, request and response connection factory JNDI names, listener port name and data binding class name. This is a page you should check to verify the configured resources.


What to do next

The import that will communicate to the existing JMS client application is completed. You should test it before you attach it to your SOA application to ensure it is working as designed. To do this, you can use the test component feature of the integration test client. Once you are certain that it is correct, you can then connect your SOA application to the import you just created.

Create applications with MQ JMS bindings