17 Oracle Business Rules

17.1 Standalone OC4J Rule Author Installation

To install Rule Author in a Standalone OC4J, do the following:

1. Deploy Rule Author EAR, found in /Disk2/rules/webapps/ruleauthor_s.ear.

2. Create a security group "rule-administrators".

3. Create a Rule Author user, for example, ruleadmin, and add this user to the "rule-administrators" group.

4. Copy the "rules" directory from an installation of Oracle Application Server into the ORACLE_HOME of the Standalone OC4J install.

5. Stop and restart OC4J.

17.2 Multiple Inheritance Exception When Using XML Facts

When using XML Facts, the following error may occur when attempting an assertXPath call:

Oracle Business Rules RL: RL code error
RLRuntimeException: fact class multiple inheritance not supported
at line 1 column 1 in main

caused by

MultipleInheritanceException: fact class 'mypkgname.MyClassNameImpl' cannot extend
both 'mypkgname.MyClassNameType' and 'mypkgname.MyClassName'

This may be caused by the fact class declaration for ObjectFactory appearing before the fact class declaration for the other JAXB classes in the generated RL.

The workaround for this issue is to delete ObjectFactory from the imported XML facts list. There are no known scenarios in which rules will be written using this class, so it is safe to remove.

If this does not resolve the problem, it may be necessary to prevent a fact class declaration for top-level XML Object in the generated RL.

The workaround for this issue is to uncheck the "Support XPath Assertion" for the top-level object. In the case of the previous error message, this would be "mypkgname.MyClassName".

17.3 Deploying Rule Author on Non-Oracle Containers

The documentation in section, C.3 of the Oracle Business Rules User's Guide incorrectly lists the location on the OracleAS Companion CD Disk of the non-Oracle .ear files for the supported non-Oracle containers. For some platforms, these .ear files are found on Disk3 of the OracleAS Companion CD Disk, and not on Disk2, as documented.

17.4 RL serviceDateValidation Error: Fact Class Should Be Declared Earlier

In certain cases, you can receive the following RL generation error:

"Fact class should be declared earlier ...".

For example, with the following generated RL for a data model:

ruleset DM {
 function CreateDataAndTestRules()
 {
 servOrders.ServiceOrderTypeImpl sot = new
servOrders.ServiceOrderTypeImpl();
.
.
.

This causes the implemented Impl class to be autofactclassed before the Type is factclassed. When the Type is then referred to in the rules, the following error is thrown:

ClassName: A syntax error is found. Error:fact class should be declared earlier at line 5 column 3 in serviceDateValidation

To fix this problem:

Classes with complex type hierarchies, for example they both extends a class and implements an interface must have classes referenced in a particular order. If the classes are not referenced in the correct order, then the rules engine cannot correctly determine the class hierarchy.

There are two ways to fix this problem:

• Check "supports XPath" for the ServiceOrderType class; this introduces a slight performance cost.

• Change the code in the CreateDataAndTestRules function. For example, change the instance creation to:

  servOrders.ServiceOrderType sot = new servOrders.ServiceOrderTypeImpl();
  

  This parses in the right order such that the superclass is created before the implementing class.