Task 1: Using automatic exception handling

You import the start projects for the tutorial, and run the decision service.

1. Start Rule Designer on your computer in the en_US (American English) locale.
2. Close the Eclipse welcome page if it open.
3. Open the Rule perspective if it is not open. Click Window > Open Perspective > Other > Rule to open the perspective.
4. Import the start project that you downloaded from GitHub:
   1. In the Rule perspective, click File > Import.
   2. In the Import wizard, expand General > Existing Projects into Workspace, and click Next.
   3. Choose Select root directory, and browse to <InstallDir>/start. InstallDir is the name of the directory to which you downloaded the start project from GitHub.
   4. Click Select All, and in Options, click Copy projects into workspace.
   5. Click Finish.

   The Rule Explorer displays six projects:

   

   The Java™™ project loan-validation-xom defines an execution object model (XOM) for rule execution. The main decision service, Loan Validation Service, references the other projects.

5. From the Run menu, select Run Configurations.
6. Expand Decision Operation, and select the run loan validation configuration:
   
7. Click Run.
   The Console view shows the results, which include an exception error.

Because the exception occurs in a rule condition, you decide to try to fix it by using automatic exception handling.

1. In the Rule Explorer, right-click Loan Validation Service.
2. In the pop-up menu, click Properties, and select Rule Engine in the left column of the Properties dialog.
3. Select Automatic exception handling in conditions, and then click OK:
   
4. Run the run configuration that is shown in step 1 of this task.
   The results no longer show an exception error. The decision engine automatically handles the exception. To determine where the exception takes place, you add more logging information to the results.

You add additional logging information to determine where the decision engine automatically handles the exception error. First, you look at the Loan Validation Service/logging.properties file, and set it as the logging configuration file. Then, you set the Java VM parameter of the run configuration to declare the path to the logging configuration file.

1. In the Rule Explorer, double-click Loan Validation Service/logging.properties.
   The file sets the Console as a logging handler:

   handlers = java.util.logging.ConsoleHandler

   It also sets the log level for the automatic exception handling to FINE.

2. Open Run > Run Configurations, and select the run loan validation configuration.
3. Open the Parameters and Arguments tab, and add the following VM argument:

   -Djava.util.logging.config.file="${workspace_loc}/Loan Validation Service/logging.properties"

4. Click Apply, and then click Run.

   The Console shows the results, which include a log message for the automatic exception handling. The results tell you that the exception takes place in a condition in the checkZipcode rule.