The method you mention for Shared Resources Tool is in it's service class org.lamsfoundation.lams.tool.rsrc.service.IResourceService and its implementation in org.lamsfoundation.lams.tool.rsrc.service.ResourceServiceImpl. If you were using our ToolBuilder, the name "Resource" most probably has been changed to something else (for example "Skype", if your tool is named so). Still, this method should be available even in version 2.1 - I've checked.
You may also get Tool Content ID when a lesson is created. The original Learning Design is copied and tools get new ID.
You can observe it LamsCoreToolService where the method notifyToolToCopyContent() is called which then calls newInstance() method in Resource class (or any other tool's main class). You could get the Content ID then, but there is a catch: this method newInstance() is called in several other occasions like importing and exporting the tool. It might be tricky to detect which situation occurs at the particular moment. So I think it's better to extract this parameter when coping with LearningAction - it's always somewhere there (as a request parameter or in session map).
Good luck!
Posted by Marcin Cieslak