question: public static String trim ( String list , String delimiter , int [ ] removeInfo , boolean multiCharacterDelimiter ) { if ( list . length ( ) == 0 ) return "" ; if ( multiCharacterDelimiter && delimiter . length ( ) > 1 ) { int from = 0 ; while ( list . length ( ) >= from + delimiter . length ( ) ) { if ( list . indexOf ( delimiter , from ) == from ) { from += delimiter . length ( ) ; removeInfo [ 0 ] ++ ; continue ; } break ; } if ( from > 0 ) list = list . substring ( from ) ; while ( list . length ( ) >= delimiter . length ( ) ) { if ( list . lastIndexOf ( delimiter ) == list . length ( ) - delimiter . length ( ) ) { removeInfo [ 1 ] ++ ; list = list . substring ( 0 , list . length ( ) - delimiter . length ( ) ) ; continue ; } break ; } return list ; } if ( list . length ( ) == 0 ) return "" ; int from = 0 ; int to = list . length ( ) ; char [ ] del = delimiter . toCharArray ( ) ; char c ; outer : while ( list . length ( ) > from ) { c = list . charAt ( from ) ; for ( int i = 0 ; i < del . length ; i ++ ) { if ( c == del [ i ] ) { from ++ ; removeInfo [ 0 ] ++ ; continue outer ; } } break ; } outer : while ( to > from ) { c = list . charAt ( to - 1 ) ; for ( int i = 0 ; i < del . length ; i ++ ) { if ( c == del [ i ] ) { to -- ; removeInfo [ 1 ] ++ ; continue outer ; } } break ; } int newLen = to - from ; if ( newLen < list . length ( ) ) { return list . substring ( from , to ) ; } return list ; }
target:  trims a string list, remove all empty delimiter at start and the end