question: public static boolean isWhitespaceStr ( String str ) { if ( str == null ) { return false ; } str = str . trim ( ) ; for ( int i = 0 ; i < str . length ( ) ; i ++ ) { if ( ! Character . isWhitespace ( str . charAt ( i ) ) ) { return false ; } } return true ; }
target:  Checks if the input String is Whitespace only.