java 判断IP地址是否合法，是IPV4，还是IPV6

    /**
     * 判断所有的IP地址
     * @param IP
     * @return
     */
    public String validIPAddressAll(String IP) {

        if (!IP.contains(".") && !IP.contains(":")) {
            return "Neither";
        }
        //如果是IPV4
        if (IP.contains(".")) {
            if (IP.endsWith(".")) {
                return "Neither";
            }
            String[] arr = IP.split("\\.");
            if (arr.length != 4) {
                return "Neither";
            }

            for (int i = 0; i < 4; i++) {
                if (arr[i].length() == 0 || arr[i].length() > 3) {
                    return "Neither";
                }
                for (int j = 0; j < arr[i].length(); j++) {
                    if (arr[i].charAt(j) >= '0' && arr[i].charAt(j) <= '9') {
                        continue;
                    }
                    return "Neither";
                }
                if (Integer.valueOf(arr[i]) > 255 || (arr[i].length() >= 2 && String.valueOf(arr[i]).startsWith("0"))) {
                    return "Neither";
                }
            }
            return "IPv4";
        }//如果是IPV4

        //如果是IPV6
        if (IP.contains(":")) {
            if (IP.endsWith(":") && !IP.endsWith("::")) {
                return "Neither";
            }
            //如果包含多个“::”，一个IPv6地址中只能出现一个“::”
            if (IP.indexOf("::") != -1 && IP.indexOf("::", IP.indexOf("::") + 2) != -1) {
                return "Neither";
            }

            //如果含有一个“::”
            if (IP.contains("::")) {
                String[] arr = IP.split(":");
                if (arr.length > 7 || arr.length < 1) {//"1::"是最短的字符串
                    return "Neither";
                }
                for (int i = 0; i < arr.length; i++) {
                    if (arr[i].equals("")) {
                        continue;
                    }
                    if (arr[i].length() > 4) {
                        return "Neither";
                    }
                    for (int j = 0; j < arr[i].length(); j++) {
                        if ((arr[i].charAt(j) >= '0' && arr[i].charAt(j) <= '9') || (arr[i].charAt(j) >= 'A' && arr[i].charAt(j) <= 'F')
                                || (arr[i].charAt(j) >= 'a' && arr[i].charAt(j) <= 'f')) {
                            continue;
                        }
                        return "Neither";
                    }
                }
                return "IPv6";
            }

            //如果不含有“::”
            if (!IP.contains("::")) {
                String[] arr = IP.split(":");
                if (arr.length != 8) {
                    return "Neither";
                }
                for (int i = 0; i < arr.length; i++) {
                    if (arr[i].length() > 4) {
                        return "Neither";
                    }
                    for (int j = 0; j < arr[i].length(); j++) {
                        if ((arr[i].charAt(j) >= '0' && arr[i].charAt(j) <= '9') || (arr[i].charAt(j) >= 'A' && arr[i].charAt(j) <= 'F')
                                || (arr[i].charAt(j) >= 'a' && arr[i].charAt(j) <= 'f')) {
                            continue;
                        }
                        return "Neither";
                    }
                }
                return "IPv6";
            }
        }//如果是IPV6
        return "Neither";
    }

        System.out.println(object.validIPAddressAll("172.16.254.1"));//IPv4
        System.out.println(object.validIPAddressAll("1e1.4.5.6"));//Neither
        System.out.println(object.validIPAddressAll("12..33.4"));//Neither
        System.out.println(object.validIPAddressAll("1212.132123.33434.41221"));//Neither
        System.out.println(object.validIPAddressAll("2001:0db8:85a3:0:0:8A2E:0370:7334:"));//Neither
        System.out.println(object.validIPAddressAll("2001:0db8:85a3:000:0:8A2E:0370:7334"));//IPv6
        System.out.println(object.validIPAddressAll("2001:0db8:85a3:000:0:8A2E:0370:73d34"));//Neither
        System.out.println(object.validIPAddressAll("::"));//Neither
        System.out.println(object.validIPAddressAll("::1"));//IPv6
        System.out.println(object.validIPAddressAll("：：1"));//Neither
        System.out.println(object.validIPAddressAll("123::566::ae4"));//Neither
        System.out.println(object.validIPAddressAll("2001:0db8:85a3:000:0:8A2E::"));//IPv6
        System.out.println(object.validIPAddressAll("2001:0db8:85a3:vcsd:0:8A2E::"));//Neither

以上基于jdk1.8

更多可见：java正则表达式 判断字符串是否含有字母

java，String.split用法

当然如果用正则表达式应该也可以。