Create Custom functions in OPA

Below is the procedure to create custom functions in OPA (Oracle Policy Automation).

• Copy the determinations-engine.jar file to library path from OPA (the file exists under the path <project>\Release\web-determinations\WEB-INF\lib\)
• Create a java class by extending the class “CustomFunction”. Note that a separate class is required to define for every custom function to be used in OPA
• Overwrite the “evaluate” method which will handle the user request

public Object evaluate(EntityInstance entityInstance, Object[] objects)

• The class would be like below

public class GetLocCountry extends CustomFunction {

    public GetLocCountry() {

        super();

    }

    public Object evaluate(EntityInstance entityInstance, Object[] objects) {

        return null;

    }

}

• Make jar to the class file (or include all the classes created into a single jar file)
• Copy the jar file to the below path of the OPA project

<OPA project>\Development\Extensions\lib\

• Create extension.xml file under Extensions folder. See below sample extension.xml file

<extension>

    <functions>

        <function name="getLocation" return-type="text">

            <arg name="country_name" type="text"/>

            <handler platform="java”     class="cf.services.GetLocCountry"/>

        </function>

    </functions>

</extension>

• Build and Run the OPA project