There are no predifined samples available for BI 4.0. However apart from webi reports all other samples work for BI 4.0 as well.
Refer to the below link to find the relavant samples
Crystal reports:
http://wiki.scn.sap.com/wiki/display/BOBJ/Java+RAS+SDK+Samples
Webi Reports:
http://scn.sap.com/docs/DOC-51447
SAP has moved Web Intelligence(Report Engine) SDK to RESTful WebSerices starting 4.0 SP6 and 4.1. Many of the eatures have been deprectaed from the Report Engine sdks in BI 4.x and have been introduced in Rest sdks.
To knopw what is still supported by Report Engine SDKs for webi, you can download the Web Intelligence Report Engine Java SDK Developer Guide for BI 4.0 SP 4 available here.
In the developer guide, refer to section "6.4 Viewing reports - Overview".
This section discusses how to use ReportEngine SDK to view Web Intelligence reports.
Refer to the guides available at help.sap.com for any referrences.
Thanks,
Prithvi