Using Java in a message map

In the Graphical Data Mapping editor, you can use methods in a Java™ class to define a transformation, to define a conditional expression, or to change the value of an input parameter in another function.

About this task

The following guidelines apply when you use a Java class in a map:

You can use static methods that return the appropriate type for the value of the output elements that they set.
The values of the map input elements that are used as parameters of a static method must have the appropriate type.
Do not define Java methods with data type overloading and then use the methods in a map. The map fails at run time with the following error: IXJXE1039E: [ERR 0786] Multiple methods with the correct arity were found in the class '<class>' when attempting to evaluate a call to the Java extension function '{http://<class>;}<method>' with arity of <N>.
In a Custom Java transform, you can call Java methods that include MbElement data type arguments.
When you define conditional expressions, you cannot use Java methods that include MbElement data type arguments.
When you define conditional expressions, you can use Java methods that use the DOM API. For more information on the supported types, see Custom Java.

Procedure

When you add a Java class to a map, you can use Java methods in any of the following situations:

To use custom Java code in a Custom Java transform. For more information, see Mapping an element by using a Custom Java transform and Processing complex or repeating elements in a Custom Java transform.
To alter the value of an input argument to an XPath function.

You alter the value in the Properties page of the XPath function. You can use content assist in the Value column that is available in the General tab to help you assign the elements of the source schema. For more information, see Built-in XPath transforms
To define a conditional expression. For more information, see Defining a Java conditional expression for a transform.

Note: To define the conditional expression, you can define an XPath expression or a call to a static method on an imported Java class. You can also create a complex expression that includes XPath, Java, and any extension functions such as iib:getUserDefinedProperty("propertyname").

What to do next

Deploy and test the message map. For more information, see Troubleshooting a message map.