Semantic Layer java SDKs is for (.unx) universes.
You should be able to find the samples available with your BI 4.x installation.
Guides are available at
navigate to Analytics--> SAP BusinessObjects Business Intelligence Platform--> Select your Product version and navigate to development information to find all the SDK related documents.
Refer to the developers guide to find out the location to samples and all the relavent information about what is ossible using the Semantic layer SDKs.
There are many new features added in Semantic Layer SDKs from BI 4.0 to 4.1. All the information is available in the dev guides.
Below is the link to BI 4.1 SP6 guide
BI Semantic Layer Java SDK Developer Guide
Thanks.