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;
}