GuilinDev

Lc0468

05 August 2008

468 Validate IP Address

验证是否IPv4和IPv6

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84

class Solution {
    private boolean isIPv4(String IP) {
        int cnt = 0;
        for (char ch : IP.toCharArray()) {
            if (ch == '.') {
                cnt++;
            }
        }

        if (cnt != 3) {
            return false;
        }

        String[] fields = IP.split("\\.");
        if (fields.length != 4) {
            return false;
        }

        for (String field : fields) {
            if (field.isEmpty() || field.length() > 3) {
                return false;
            }

            int sz = field.length();
            for (int i = 0; i < sz; ++i) {
                if (!Character.isDigit(field.charAt(i))) {
                    return false;
                }
            }

            int num = Integer.valueOf(field);
            if (!String.valueOf(num).equals(field) || num < 0 || num > 255) {
                return false;
            }
        }

        return true;
    }

    private boolean isIPv6(String IP) {
        int cnt = 0;
        for (char ch : IP.toCharArray()) {
            if (ch == ':') {
                cnt++;
            }
        }

        if (cnt != 7) {
            return false;
        }

        String[] fields = IP.split(":");
        if (fields.length != 8) {
            return false;
        }

        for (String field : fields) {
            if (field.isEmpty() || field.length() > 4) {
                return false;
            }

            int sz = field.length();
            for (int i = 0; i < sz; ++i) {
                if (!Character.isDigit(field.charAt(i)) && (field.charAt(i) < 'A' || field.charAt(i) > 'F')) {
                    return false;
                }
            }
        }

        return true;
    }

    public String validIPAddress(String IP) {
        if (isIPv4(IP)) {
            return "IPv4";
        }

        if (isIPv6(IP.toUpperCase())) {
            return "IPv6";
        }

        return "Neither";
    }
}

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

public static String validIPAddress(String IP) {
        String[] ipv4 = IP.split("\\.",-1);
        String[] ipv6 = IP.split("\\:",-1);
        if(IP.chars().filter(ch -> ch == '.').count() == 3){
            for(String s : ipv4) if(isIPv4(s)) continue;else return "Neither"; return "IPv4";
        }
        if(IP.chars().filter(ch -> ch == ':').count() == 7){
            for(String s : ipv6) if(isIPv6(s)) continue;else return "Neither";return "IPv6";
        }
        return "Neither";
    }
    public static boolean isIPv4 (String s){
         try{ return String.valueOf(Integer.valueOf(s)).equals(s) && Integer.parseInt(s) >= 0 && Integer.parseInt(s) <= 255;}
         catch (NumberFormatException e){return false;}
    }
    public static boolean isIPv6 (String s){
        if (s.length() > 4) return false;
        try {return Integer.parseInt(s, 16) >= 0  && s.charAt(0) != '-';}
        catch (NumberFormatException e){return false;}
    }
This site is open source. Improve this page.