Check node

Attention: The Check node is deprecated in WebSphere Message Broker Version 6.0. Although message flows that contain a Check node remain valid in WebSphere Message Broker Version 6.0, where possible redesign your message flows so that any Check node is replaced by a Validate node.

This topic contains the following sections:

Purpose

Use the Check node to compare the structure of a message arriving on its input terminal with a message structure definition that you supply when you configure the Check node. The message structure definition comprises the message domain; if the message domain is MRM, you can also specify any combination of message set and message type. The Check node checks only the message structure definition; it does not check the message body.

The domain, set, and type of the message are collectively called the message template. The domain defines the parser that is used for the message. The set is the message set to which the message belongs. The type is the structure of the message itself. You can check the incoming message against one or more of these properties. The message property is checked only if you select its corresponding Check property, which means that a message property containing a null string can be compared.

If the message properties match the specification, the message is propagated through the match terminal of the node. If the message properties do not match the specification, the message is propagated through the failure output terminal. If the failure terminal is not connected to some failure handling processing, an exception is thrown.

The Check node is represented in the workbench by the following icon:

Check node icon

Using this node in a message flow

You can use the Check node to ensure that the message is routed appropriately through the message flow. For example, you can configure it to direct a message that requests stock purchases through a different route from that required for a message that requests stock sales.

Another example of this node's use is the receipt of electronic messages from your staff at your head office. These messages are used for multiple purposes, for example to request technical support or stationery, or to advise you about new customer leads. These messages can be processed automatically because your staff fill in a standard form. If you want these messages to be processed separately from other messages received, use the Check node to ensure that only staff messages that have a specific message type are processed by this message flow.

Configuring the Check node

When you have put an instance of the Check node into a message flow, you can configure it. Right-click the node in the editor view and click Properties. The node's basic properties are displayed.

All mandatory properties for which you must enter a value (those that do not have a default value defined) are marked with an asterisk on the properties dialog.

Configure the Check node as follows:

  1. To check the parser to be used for the incoming message, select the box Check Domain and enter one of the following values (in uppercase) in the Domain field:
    • MRM
    • XML
    • XMLNS
    • JMSMap
    • JMSStream
    • IDOC
    • MIME
    • BLOB

    Use this option to check that a message belongs to a particular domain.

  2. If you are using the MRM or IDOC parser, check that the incoming message belongs to a particular message set by selecting the box Check Set and entering the identifier of the message set in Set. This identifier can be found in the properties of the message set when you view it in the editor. WebSphere Message Broker generates the identifier when you create the message set; it is something like DHHJEQC06U001. You must enter the identifier exactly as shown in the message set properties.

    Leave Set clear for the XML, JMS, MIME, and BLOB parsers.

    Use this option to check that a message belongs to a particular message set.

  3. If you are using the MRM parser, check that the incoming message is a particular message type by selecting the box Check Type and entering the identifier of the message in Type.

    This identifier can be found in the properties of the message when you view the message in the editor. You specify the message identifier when you create the message. You must enter the identifier exactly as shown in the message properties.

    Leave Type clear for the XML, JMS, IDOC, MIME, and BLOB parsers.

    Use this option to check that a message matches a particular definition.

  4. Select Description in the properties dialog navigator to enter a short description, a long description, or both.
  5. Click Apply to make the changes to the Check node without closing the properties dialog. Click OK to apply the changes and close the properties dialog.

    Click Cancel to close the dialog and discard all the changes that you have made to the properties.

Terminals and properties

The Check node terminals are described in the following table.

Terminal Description
In The input terminal that accepts a message for processing by the node.
Failure The output terminal to which the message is routed if the incoming message does not match the specified properties.
Match The output terminal to which the message is routed if the incoming message matches the specified properties.

The following tables describe the node properties; the column headed M indicates whether the property is mandatory (marked with an asterisk on the properties dialog if you must enter a value when no default is defined), the column headed C indicates whether the property is configurable (you can change the value when you add the message flow to the bar file to deploy it).

The Check node Basic properties are described in the following table.

Property M C Default Description
Domain No No   The name of the domain.
Check Domain Yes No Cleared Whether to check the incoming message against the Domain property. If you select the check box, this action is performed.
Set No No   The message set to which the incoming message belongs.
Check Set Yes No Cleared Whether to check the incoming message against the Set property. If you select the check box, this action is performed.
Type No No   The message identifier.
Check Type Yes No Cleared Whether to check the incoming message against the Type property. If you select the check box, this action is performed.

The Check node Description properties are described in the following table.

Property M C Default Description
Short Description No No   A brief description of the node.
Long Description No No   Text that describes the purpose of the node in the message flow.
Related reference
Validate node