public static void main(String[] args) {

        StringBuffer str = new StringBuffer("Java Oracle");

        System.out.println("원본 문자열 : " + str);

        System.out.println(str.delete(4, 8));

        System.out.println(str.deleteCharAt(1));

        System.out.println("deleteCharAt() 메소드 호출 후 원본 문자열 : " + str);

    }

}