The Crystal Common Classes provide you with tools to retrieve and set properties in a report. The classes provide a definition of the primary report properties, such as parameter fields, fields, and their associated values. The Crystal Common Classes are a subset of the Report Application Server (RAS) SDK, which is part of an enterprise level report creation and modification solution--the Report Application Server. Unlike the RAS SDK, the Crystal Common Classes are not able to make permanent changes to report properties. Any properties that are modified will only be effective for the duration of the session. For more information on how to permanently modify reports or dynamically create reports, see the Crystal Reports for BEA WebLogic Workshop Developer's Guide.

The Crystal Common Classes consist of two packages, {@link com.crystaldecisions.sdk.occa.report.data} and {@link com.crystaldecisions.sdk.occa.report.lib}. The `data` package provides the report definition classes, while the `lib` package provides utility classes that are used by the classes in `data`.