static Collection < String > columnToAlias ( Settings settings ) { FieldAlias fa = alias ( settings ) ; List < String > columnNames = StringUtils . tokenize ( settings . getProperty ( HiveConstants . COLUMNS ) , "," ) ; // eliminate virtual columns // we can't use virtual columns since some distro don't have this field... for ( String vc : HiveConstants . VIRTUAL_COLUMNS ) { columnNames . remove ( vc ) ; } for ( int i = 0 ; i < columnNames . size ( ) ; i ++ ) { String original = columnNames . get ( i ) ; String alias = fa . toES ( original ) ; if ( alias != null ) { columnNames . set ( i , alias ) ; } } return columnNames ; }
Renders the full collection of field names needed from ES by combining the names of the hive table fields with the user provided name mappings .