ResultSet.getInt()

[Thomas Vatter]

I have a problem using ResultSet.getInt() method, each call returns an 
exception:
org.apache.derby.client.am.SqlException: Invalid operation:
wasNull() called with no data retrieved
       at org.apache.derby.client.am.ResultSet.wasNull(Unknown Source)
The code is
       ResultSetMetaData RSMD = RS.getMetaData();
       int INTcols = RSMD.getColumnCount();
       String STRtemp = null;
       while(RS.next())
       {
           String STRvalue = new String();           
           for(int INTcol = 1; INTcol <= INTcols; INTcol++)
           {
               int INTdummy = RSMD.getColumnType(INTcol);              
               switch((int)RSMD.getColumnType(INTcol))
               {
                       if(!RS.wasNull()) // raises exception
                       
{                                                                                                    

                           STRvalue = "" + 
RSaktuelles.getInt(INTcol);                                              
                       } 
       ...
       }
        }
   }

what can I do to avoid this exception

tom