Get Nodes,Node Type details within the node of type Sub-process.

Hi Team,
Request your Suggestion on the below requirement.

1. How to get the list of Nodes within the node of type Sub-Process( (Embedded , Adhoc, Reusable ) before the process started.

2. How to place completion condition for adhoc sub-process" as the below mentioned condition reports method not found exception:
getActivityInstanceAttribute(\"numberOfActiveInstances\") == 0"

3. Mapping JASON object to JBPM DO object directly without parsing the JASON message.

Please provide your inputs to proceed further.

Regards,
Sandeep Mouray