If you want to find out the state of the process, you can get it from the ProcessInstanceLog object.
But may be by state, you mean the current node in the process which is active.
In your code though, how do you get the "wflowProcessInstance" ???
Anyway. You could use the following code.
Process process = kbase.getProcess(processDefId);
for (Node node : ((WorkflowProcessImpl) process).getNodes())
nodeInstanceLogList = JPAProcessInstanceDbLog.findNodeInstances(processInstId, NumberFormat.getNumberInstance().format(node.getId()));
if(nodeInstanceLogList.size() == 1)
//add the node to the list, as there may be more than one node active.