question: private static String formatList ( String [ ] stringList , String listPattern , String listCompositionPattern ) { if ( listPattern == null || listCompositionPattern == null ) { StringBuilder result = new StringBuilder ( ) ; for ( int i = 0 ; i < stringList . length ; ++ i ) { if ( i > 0 ) { result . append ( ',' ) ; } result . append ( stringList [ i ] ) ; } return result . toString ( ) ; } if ( stringList . length > 3 ) { MessageFormat format = new MessageFormat ( listCompositionPattern ) ; stringList = composeList ( format , stringList ) ; } Object [ ] args = new Object [ stringList . length + 1 ] ; System . arraycopy ( stringList , 0 , args , 1 , stringList . length ) ; args [ 0 ] = new Integer ( stringList . length ) ; MessageFormat format = new MessageFormat ( listPattern ) ; return format . format ( args ) ; }
target:  Format a list using given pattern strings. If either of the patterns is null, then a the list is formatted by concatenation with the delimiter ','.