question: public List < Map < String , String > > list ( Database conn ) throws SQLException { ResultSet rs = null ; Statement statement = conn . createStatement ( ) ; List < Map < String , String > > shardToChannels = new ArrayList < Map < String , String > > ( ) ; try { rs = statement . executeQuery ( select ) ; while ( rs . next ( ) ) { Map < String , String > shard = new HashMap < String , String > ( ) ; shard . put ( ShardChannelTable . SHARD_ID_COL , rs . getString ( ShardChannelTable . SHARD_ID_COL ) ) ; shard . put ( ShardChannelTable . CHANNEL_COL , rs . getString ( ShardChannelTable . CHANNEL_COL ) ) ; shardToChannels . add ( shard ) ; } } finally { close ( rs ) ; close ( statement ) ; } return shardToChannels ; }
target:  Return a list of currently known shard/channel assignments.