Report viewing is done primarily through the HTML report viewer included with the Crystal Reports Java Reporting Component. This report viewer is a control that runs inside a JSP or servlet. Its job is to get the information the report engine produces for a given page of a report and render that data to HTML format into the page's response stream.
The programmatic entry point to the report viewer is a class called CrystalReportViewer. This class is found in the com.crystaldecisions.report.web.viewer package. It can be instantiated as follows:
CrystalReportViewer viewer = new CrystalReportsViewer();
Make sure you add the class's package name in the import attribute of the page clause like this:
<%@ page ...