[Java] ipToLong 與 longToIp

1. public class IpToLong { 
2.  
3.    public static long ipToLong(String ip) { 
4.        long result = 0; 
5.        String[] numbers = (ip + ".0.0.0").split("\\."); 
6.  
7.        for (int i = 0; i < 4; i++) { 
8.            result = result << 8; 
9.            result |= Long.parseLong(numbers[i]) & 0xFF; 
10.        } 
11.  
12.        return result; 
13.    } 
14.  
15.  
16.    public static String longToIp(long ip) { 
17.        return (ip >> 24 & 0xFF) + "." + 
18.               (ip >> 16 & 0xFF) + "." + 
19.               (ip >> 8 & 0xFF) + "." + 
20.               (ip & 0xFF); 
21.    } 
22.  
23.  
24.  
25.    public static void main(String[] args) { 
26.  
27.        String[] testList = { 
28.            "0.0.0.0", 
29.            "255.255.255.255", 
30.            "192.168.1.2" 
31.        }; 
32.  
33.        for (String ip : testList) { 
34.            long ipNum = ipToLong(ip); 
35.            System.out.printf( 
36.                "%s | %s | %s\n", ip, longToIp(ipNum), ipNum 
37.            ); 
38.        } 
39.    } 
40. } 

public class IpToLong {

    public static long ipToLong(String ip) {
        long result = 0;
        String[] numbers = (ip + ".0.0.0").split("\\.");

        for (int i = 0; i < 4; i++) {
            result = result << 8;
            result |= Long.parseLong(numbers[i]) & 0xFF;
        }

        return result;
    }


    public static String longToIp(long ip) {
        return (ip >> 24 & 0xFF) + "." +
               (ip >> 16 & 0xFF) + "." +
               (ip >> 8 & 0xFF) + "." +
               (ip & 0xFF);
    }



    public static void main(String[] args) {

        String[] testList = {
            "0.0.0.0",
            "255.255.255.255",
            "192.168.1.2"
        };

        for (String ip : testList) {
            long ipNum = ipToLong(ip);
            System.out.printf(
                "%s | %s | %s\n", ip, longToIp(ipNum), ipNum
            );
        }
    }
}

Output:

1. 0.0.0.0 | 0.0.0.0 | 0 
2. 255.255.255.255 | 255.255.255.255 | 4294967295 
3. 192.168.1.2 | 192.168.1.2 | 3232235778 

0.0.0.0 | 0.0.0.0 | 0
255.255.255.255 | 255.255.255.255 | 4294967295
192.168.1.2 | 192.168.1.2 | 3232235778