public JSONObject execServiceOperation(String operationName, HashMap<String, Object> input) throws Exception
They have almost the identical function, which is to execute the remote Operation <operationName> at the remote server, which could be specified with <designatedHost>, without a session. You can use KeyedCollection as the input and output data. You can also use HashMap<String, Object>/JSON as the input and output data in the application that is NOT aware of UDTT Context Data.
The <designatedHost> is the id of the field defined at ServiceEngine.Configuration.ServiceURI.
If <designatedHost> is missing, the remote host(Service URI) would be determined by <operationName> at ConfigManager.getServiceURI(operationName) and it would use the default one defined at ServiceEngine.Configuration.ServiceURI by default (the current implementation of ConfigManager).