Hi Hajer,
Desktop Intelligence documents are partially supported through Report Engines SDKs in XI 3.1. You can only perform the following through Report Engine Java SDKs:
1. Viewing
2. Refreshing
3. Analyzing
For handling Desktop intelligence through Report Engine SDKs, you have to get the Full Client Report Engine services like below:
reportEngine = reportEngines.getService( ReportEngineType.FC_ReportEngine);
The jars are same that you are using for handling Webi documents, as we only have to change the report engine service type for handling the desktop intelligence documents.
Please refer some of the sample codes from the link & developer guide to get an idea how to handle the Desktop intelligence documents & what are the difference in handling the desktop intelligence documents from the Web intelligence document through RE Java SDKs.
The developer guide have all the information to set up the development environment & what jars are needed to setup the build path.
Hope this helps.
Thanks,
Shailendra