A custom method is used to call a function from a custom Java class in a package. It is declared and used globally for all target elements. 

To use a custom method in a mapping activity, you need to map it to a target element. This will successfully execute the custom method when you execute the mapping activity in the process flow. 

Prerequisites

Declaring a Custom Method 

  1. Ensure that the source and target schemas are loaded and all their elements are listed under their respective nodes.
  2. Click the Global tab displayed in the Mapping Graph Area. All tabs of the Global tab are displayed.

  3. Click the Custom Methods tab. 

  4. Click the Add New Method (  ) button to add a Custom Method. A row is inserted with the listed columns.

  5. The value 'java' is automatically displayed in the Alias column. This is a read-only field.
  6. Click Alias field and then press Enter or Tab key to activate the Class (PKG) field.
  7. Enter the fully qualified name of the Java class in the Class (PKG) field and press Enter or Tab key to activate the Method field.
  8. Enter the name of the custom method in the Method column and press Enter or Tab key to activate the #Parameter field.

  9. Enter the number of arguments taken by Method in the #Parameter column. A custom method can take any number of arguments. However, if you enter a value greater than 4, then a warning message appears.

  10. Click OK to close the message. This saves the custom method and displays it under Custom Methods in the Parameters Panel.

To remove a custom method, select the custom method and click the Remove selected method () button.

Alternately, you can edit or delete a custom method from the Parameters Panel itself. For details, refer to the   Managing a Global Variable from Parameter Panel section.

Map Custom Method to Target Element
Once you have created a custom method, you can map it to a target element. To map:

  1. Ensure that the source and target schemas are loaded and all their elements are listed under their respective nodes.
  2. Click the Node tab displayed in the Mapping Graph Area. All tabs of the Node tab are displayed. Click Mapping Rules tab.
  3. Select a target element. This displays the selected target element node in the Mapping Graph Area.

  4. Double-click the required custom method under Custom Methods in the Parameters Panel. The selected method node is displayed in the Mapping Graph Area.


    If the custom method is defined with more than 4 parameters, then double-clicking the custom method will display the warning message. Once you click OK, you need to define the mapping using Textual Rules.

  5. Click two source elements. The selected source nodes are displayed in the Mapping Graph Area.
  6. Create a link from the output of the first source element to the first input of the custom method node.
  7. Create a link from the output of the second source element to the second input of the custom method node.

  8. Create a link from the output of the custom method node to the input of the target element.

  9. Click the Apply Mapping (  ) button. This maps the custom method to the target element.

  10. Save the mapping activity and exit the Data Mapper.

     

    You can view and validate the generated mapping XSL,  view the target XML and,  view and validate mapping output, before saving the mapping activity.