Using the CA Rule Engine › Construction of Java Client Applications › Using the WrapperMaker Tool

Using the WrapperMaker Tool

The WrapperMaker tool facilitates the generation of Java classes that wrap the rule engine classes for an existing rulebase. The WrapperMaker tool takes either a rulebase file (RDL or binary) or a rulebase App Interface document file (see Rulebase Structures) and perform the following tasks:

• For any class defined at the rulebase level, the tool generates a corresponding Java class that wraps the rulebase class. The generated classes satisfy all requirements specified in Rules for Constructing Java Classes. In addition, each generated class also provides a second constructor that takes instance name as an argument, and methods equals(), hashcode(), and toString().
• The tool generates a template session Java class that declares all static instances defined at the rulebase level as private static members of the session class. The template session Java class also defines the getRuleServiceProvider() function (which wraps CA Rule Engine specific initializations for JSR-94) to facilitate the obtaining of the RuleServiceProvider.

The user can add rule session logic to the template session Java class to perform inference tasks.

For ease of invocation of the WrapperMaker tool, the wrappermaker batch or script files have been supplied in the /bin folder in the CA Rule Engine distribution. The syntax for invoking the tool is:

wrappermaker rulebase/APIfile [JavaPackageName [rootOutputFolder]]

where the user can also optionally specify the Java package name for the generated Java class files and the root folder to which the hierarchy of classes will be written. If a rulebase file is supplied as the first parameter, an App Interface document file will also be generated. When optional parameters are not supplied, the generated Java classes will be in the default package and files will be written to the same folder where the rulebase file or App Interface document file resides.

The WrapperMaker tool script also supports drag and drop operation if drag and drop is supported by the OS GUI. When a rulebase file or an App Interface document file is dropped onto the WrapperMaker tool script icon, it is equivalent to invoke the script with the name of that file as the first parameter. Since a Java IDE such as Eclipse can automatically adjust package names when a new Java source file is added to a project, drag and drop operation may be the simplest method for invoking the WrapperMaker tool.

For more information

Acquire the RuleExecutionSet and RuleSession