Hi Chris,
Do you mean passing a value to a BPM from java ?
If so, yes you can do that. While starting the BPM, you can set the values to various input parameters of BPM and start it.
Example below.
Map<String, Object> variables = new HashMap<String, Object>();
variables.put("projectName", "IPEMS");
variables.put("projectLocation", "Hyderabad");
runtimeService.startProcessInstanceByKey(bpmName, variables);