Follow Action problem updated from RTC3.0.1 To RTC4.0.6

Now I met some problem when I update my server from RTC3.0.1 to RTC4.0.6.

I have some precondition and follow action written which runs well for RTC3.0.1.But last day, I update all my RTC-SDK and RTC client and RTC Servet to  4.0.6. The error occured.

First problem, I still can press 'build all' button in update site project to build the old  plug-in project without error in RTC 4.0.6  developping enviroment, but when the follow action is triggered after deploying in server side, the error message with "No method found occur". I don't know why it happened after compile correctly.

Second, I can not found com.ibm.team.repository.common in the dependencies tab page. It can be found in the RTC3.0.1. So,what's happy?which plug-in replaced it?

Third problem, it seems that the error occured on findWorkspaces api of SCMQueryService class. No this method found.Is the method deprecated? Please tell me which API should I used to to search a stream to fit my original logic.

ItemQueryResult result= scmQuery.findWorkspaces(searchExistingStreams, Integer.MAX_VALUE, null);
for (Object stream : result.getItemHandles()) {
 if (stream instanceof IWorkspaceHandle) {
  wsHandleList.add((IWorkspaceHandle)stream);
 }
}.

below is the original API for RTC3.0.1 :
public List<IWorkspaceHandle> findWorkspacesHandleByStreamNamePrefix(String streamNamePrefix) throws TeamRepositoryException {
 List<IWorkspaceHandle> wsHandleList = new ArrayList<IWorkspaceHandle>();
 IWorkspaceSearchCriteria searchExistingStreams= IWorkspaceSearchCriteria.FACTORY.newInstance();
 searchExistingStreams.setKind(IWorkspaceSearchCriteria.STREAMS);
 searchExistingStreams.setPartialOwnerName("%_DEV");
 searchExistingStreams.setPartialName(streamNamePrefix);
 ItemQueryResult result= scmQuery.findWorkspaces(searchExistingStreams, Integer.MAX_VALUE, null);
 for (Object stream : result.getItemHandles()) {
  if (stream instanceof IWorkspaceHandle) {
   wsHandleList.add((IWorkspaceHandle)stream);
  }
 }
 return wsHandleList;
}