private Optional < Instant > calcLastMod ( ) { Instant globalLastMod = null ; for ( final ChannelInformation ci : this . channelService . list ( ) ) { final Optional < Instant > lastMod = ofNullable ( ci . getState ( ) . getModificationTimestamp ( ) ) ; if ( globalLastMod == null || lastMod . get ( ) . isAfter ( globalLastMod ) ) { globalLastMod = lastMod . get ( ) ; } } return Optional . ofNullable ( globalLastMod ) ; }
Find the last modification timestamp of all channels