public static String deletePattern(String a, String b) { if (a==null || b==null) { return a; } char[] bs = b.toCharArray(); StringBuilder as = new StringBuilder(); for (int j = 0; j < bs.length; j++) { for (int i = 0; i < a.length(); i++) { if (a.charAt(i)!=bs[j]) { as.append(a.charAt(i)); } } a = as.toString(); as.setLength(0); // as.delete(0, as.length()); 两种清空方法 } return a; }