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WebSphere Message Brokers
File: aa40220_
Writer: Cerys Giddings


This build: July 31, 2007 21:15:59

How do I program message flows?

New users: use the links in this topic to get information on the concepts and tasks associated with programming message flows.

How do I use message mappings?

Message mappings use a drag-and-drop interface to create and transform messages. You can use conditional logic, ESQL functions, and XPath functions to create complex mappings and transformations. You can also use message mapping to select and manipulate data in database tables. You must create a message definition for any messages that you include in a message mapping. Message map files are stored in message flow projects.
  • How do I create a message map file?

    Get instructions on how to create a message map from the Broker Development view. You can also create a message map from the nodes that support message mapping including:
  • What does the Message Mapping editor look like?

    You create and modify message mappings in the Message Mapping editor. Use this link to find out about the Message Mapping editor.
  • How do I configure message mappings?

    When you configure message mappings you can drag content from a source to a target. The source can be a message, a database, or both, and the target can be messages, database tables, or both. If your target is a database, you can select the database operation insert, update, or delete that you want to perform on the table. You can set the value for your target to be a constant, or you can use a function or expression to produce the value. Additionally, you can configure conditional mappings to set different values for targets based on the content of the sources, and to handle repeating elements in sources and targets. Follow this link to find out more about message mappings.
  • Message mapping syntax

    When you use an expression to set the value of a target in a message map, the expression must be in XPath format.
  • How do I create and call submaps and routines?

    You can reuse message maps between different message flows and message flow projects using a submap. You can also use a submap to create message mappings for a wildcard source so that you can select replacement elements, for example to select the appropriate body element from a SOAP message. In addition to calling a submap from a message map, you can call a submap from ESQL. You can also call ESQL routines from a message map. Use this link to find more information about creating and using submaps and ESQL routines.

How do I use ESQL?

Extended Structured Query Language (ESQL) is a programming language based on Structured Query Language (SQL), which is commonly used with relational databases such as DB2®. ESQL extends the constructs of the SQL language to provide support for you to work with both message and database content. ESQL can be used with the Compute, Database, and Filter nodes. Many of the WebSphere Message Broker Samples demonstrate how to use ESQL in message flows. You can view samples only when you use the information center that is integrated with the Message Brokers Toolkit. The following samples contain example ESQL code: Use the following links to find out how to use ESQL in your message flows.

How do I use Java?

You can create a Java™ class file for a JavaCompute node and code Java functions to tailor the behavior of the node. You can add any valid Java code to your JavaCompute nodes and use the Java user-defined node API to process messages. Java files are managed through the Java perspective.

The JavaCompute Node sample provides a collection of message flows that demonstrate how to use the JavaCompute node. You can view samples only when you use the information center that is integrated with the Message Brokers Toolkit.
  • How do I use a JavaCompute node?

    You can use the JavaCompute node to examine the content of an input message, transform a message, and build new messages. Follow this link to find out how to use and configure the JavaCompute node in your message flows.
  • How do I create Java code for a JavaCompute node?

    Find out how to create a Java class file using the JavaCompute node wizard. The JavaCompute node wizard creates a Java class with skeleton Java code that is based on the options that you select in the wizard. You can then modify the skeleton code to perform your own processing.
  • How do I open an existing Java file?

    You can modify existing Java code that you have created in a Java Project.
  • How do I save a Java file?

    Find out how to save your Java file.
  • How do I write Java for message flow applications?

    Get introductory information about writing Java code for your message flow applications, including how to manipulate the message tree, access databases, handle errors, and access broker properties.
  • What views and editors do I use when programming Java?

    Get a list of concept, task, and reference topics that relate to editors and views for working with Java. This link works only if you are accessing the information center from the Message Brokers Toolkit.

  • Where can I get assistance when programming Java?

    You can use code assist to provide a list of available command completions that you can select to insert into the editor. You can also use command assist to access Javadoc information about code in the Java editor. This link works only if you are accessing the information center from the Message Brokers Toolkit.

  • How do I add Java code dependencies?

    Find out how to include references to other Java projects and JAR files in your JavaCompute node code.
  • Where can I find the Java user-defined node API?

    Follow this link to the Java API for the WebSphere Message Broker classes for creating a Java user-defined node, which you can also use to code your JavaCompute node.

How do I use XML transformations?

You can use the XSLTransform node to transform an XML message into another form of XML according to the rules provided by an XSL (eXtensible Stylesheet Language) stylesheet. You can specify the location of the stylesheet to apply to this transformation in three ways:
  • Use the content of the XML data within the message itself, which transforms the message according to a stylesheet that the message itself defines.
  • Set a value within the LocalEnvironment folder.
  • Use node properties, which ensures that the transformation that is defined by this single stylesheet is applied to every message that is processed by this node.
You can find links to information on using XML transformation in this section.
  • Where can I find a sample application that demonstrates XML transformations?

    If you have the Message Brokers Toolkit installed, you can use this link to display the XMLT sample in the Samples Gallery. The XMLT sample is a message flow sample application that shows how to use a message flow to transform an XML message to another form of XML message according to the rules provided by an XSL stylesheet.You can view samples only when you use the information center that is integrated with the Message Brokers Toolkit.
  • How do I use the XSLTransform node?

    Follow this link to find out how to use and configure the XSLTransform node to transform an XML message into another form of XML.
  • Where can I find out more about XSL Transformations?

    To find out more about XML Transformations follow this link to the W3C specification of the syntax and semantics of the XSL Transformations language for transforming XML documents into other XML documents.
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This build: July 31, 2007 21:15:59

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