lang3-StringUtils

        String s = "jdk-nio.步驟.png";
        String s1 = StringUtils.substringAfterLast(s, ".");
        System.out.println(s1);//png

String suffix="jpg";
StringUtils.equalsAnyIgnoreCase(suffix, "bmp", "jpg", "jpeg", "gif", "png")
//suffix是否在後面的字符串中