question: private ManagedSystemInfo lookupManagedSystemInfo ( ISource S ) throws AdeException { ManagedSystemInfo M = null ; final String MANAGED_QUERY = String . format ( "SELECT * FROM MANAGED_SYSTEMS WHERE SOURCE_INTERNAL_ID=%s" , S . getSourceInternalId ( ) ) ; ResultSet R = null ; String osName ; int gmtOffset ; logger . trace ( String . format ( "lookupManagedSystemInfo(%s) -->entry" , S . getSourceId ( ) ) ) ; try { R = executeScrollInsensitiveQuery ( MANAGED_QUERY ) ; if ( R == null ) { final String msg = String . format ( "lookupManagedSystemInfo(%s) - unexpected null (ResultSet)" , S . getSourceId ( ) ) ; logger . error ( msg ) ; throw new AdeInternalException ( msg ) ; } if ( ExtDataStoreUtils . nonemptyQueryResult ( R ) ) { try { R . first ( ) ; gmtOffset = R . getInt ( "GMT_OFFSET" ) ; osName = R . getString ( "OPERATING_SYSTEM" ) ; M = new ManagedSystemInfo ( gmtOffset , osName ) ; } catch ( Throwable t ) { final String msg = String . format ( "lookupManagedSystemInfo(%s) - (ResultSet) extract error" , S . getSourceId ( ) ) ; logger . error ( msg ) ; throw new AdeInternalException ( msg , t ) ; } } } catch ( AdeException e ) { throw e ; } catch ( Throwable t ) { final String msg = String . format ( "lookupManagedSystemInfo(%s) caught unexpected throwable: %s" , S . getSourceId ( ) , t . getMessage ( ) ) ; logger . error ( msg ) ; throw new AdeInternalException ( msg , t ) ; } finally { if ( R != null ) { try { R . close ( ) ; } catch ( SQLException ex ) { logger . error ( "Error encountered closing the ResultSet." , ex ) ; } } } logger . trace ( String . format ( "lookupManagedSystemInfo(%s) <--exit" , S . getSourceId ( ) ) ) ; return M ; }
target:  Query the analytics database to obtain the current managed system-related information for the managed system designated by the input Source.  If there is such information in the database, return a second instance of the current class informed by those values, so that the caller knows that it should pursue a "read and perhaps modify database" logic path, based on comparing "this" instance with "that" (i.e., to determine what, if any, changes are to be made in the database). Of course, there may well be no such information, as this may be driven on a "first encounter", in which case we return a null "that", and the caller knows that it should pursue a "create various database rows" logic path. SPECIAL NOTE:  Practice shows that none of these column values can really be trusted to have content.  These are set/reset by various untrusted parties (e.g., bulk load).  It is imperative that a null value be handled and that a non-null object M be returned so that the caller is not mislead into thinking that they need to do a (erroneous, redundant) database ADD operation when in fact the designated ManagedSystem exists in the database and it is really an UPDATE operation that should be performed. Hence the super-paranoid try catch logic.