Java RMI and Threading

Hi,

We are using threading and RMI in my application. Its a continuously runing application and run it as service, We are reading some packet from the server. The issues are, 1. But some data are missing while running this. 2. When we compare string values with hashtable values it is not properl working

sample code is

Hashtable hash_modeChange   = new Hashtable();
Hashtable hash_statusChange = new Hashtable();          
if ((hash_statusChange.get(intersectionName) !=  failureType) || (hash_modeChange.get(intersectionName)!= modeOfOperation)) {                                   
                    Statement in_statusMode = con.createStatement();
                    in_statusMode.executeUpdate("INSERT INTO status_mode_history (time,intersection_name,status_flag_value,mode_of_operation) values ('" + currentTime + "','" + intersectionName + "','"+objIntersection.Status+"','"+modeOfOperation+"')");
                     hash_modeChange.put(intersectionName,modeOfOperation);
                     hash_statusChange.put(intersectionName,failureType);
 }