Java Programming IP address and number conversion code example
- 2020-12-05 17:10:24
- OfStack
Until recently, converting ip addresses to base 10, base 8, and base 106 also made it possible to visit a website.
IP converted to numbers (algorithm 2. Move left, by bit, or by implementation. More efficient.) :
public long ipToLong(String ipAddress) {
long result = 0;
String[] ipAddressInArray = ipAddress.split("\\.");
for (int i = 3; i >= 0; i--) {
long ip = Long.parseLong(ipAddressInArray[3 - i]);
//left shifting 24,16,8,0 and bitwise OR
//1. 192 << 24
//1. 168 << 16
//1. 1 << 8
//1. 2 << 0
result |= ip << (i * 8);
}
return result;
}
When the number is converted to IP, both algorithms are similar:
//ip = 3232235778
public String longToIp(long ip) {
StringBuilder result = new StringBuilder(15);
for (int i = 0; i < 4; i++) {
result.insert(0,Long.toString(ip & 0xff));
if (i < 3) {
result.insert(0,'.');
}
ip = ip >> 8;
}
return result.toString();
}
//ip = 3232235778
public String longToIp2(long ip) {
return ((ip >> 24) & 0xFF) + "."
+ ((ip >> 16) & 0xFF) + "."
+ ((ip >> 8) & 0xFF) + "."
+ (ip & 0xFF);
}
Complete code:
public class JavaBitwiseExample {
public static void main(String[] args) {
JavaBitwiseExample obj = new JavaBitwiseExample();
System.out.println("iptoLong : " + obj.ipToLong("192.168.1.2"));
System.out.println("iptoLong2 : " + obj.ipToLong2("192.168.1.2"));
System.out.println("longToIp : " + obj.longToIp(3232235778L));
System.out.println("longToIp2 : " + obj.longToIp2(3232235778L));
}
// example : 192.168.1.2
public long ipToLong(String ipAddress) {
// ipAddressInArray[0] = 192
String[] ipAddressInArray = ipAddress.split("\\.");
long result = 0;
for (int i = 0; i < ipAddressInArray.length; i++) {
int power = 3 - i;
int ip = Integer.parseInt(ipAddressInArray[i]);
// 1. 192 * 256^3
// 2. 168 * 256^2
// 3. 1 * 256^1
// 4. 2 * 256^0
result += ip * Math.pow(256, power);
}
return result;
}
public long ipToLong2(String ipAddress) {
long result = 0;
String[] ipAddressInArray = ipAddress.split("\\.");
for (int i = 3; i >= 0; i--) {
long ip = Long.parseLong(ipAddressInArray[3 - i]);
// left shifting 24,16,8,0 and bitwise OR
// 1. 192 << 24
// 1. 168 << 16
// 1. 1 << 8
// 1. 2 << 0
result |= ip << (i * 8);
}
return result;
}
public String longToIp(long i) {
return ((i >> 24) & 0xFF) +
"." + ((i >> 16) & 0xFF) +
"." + ((i >> 8) & 0xFF) +
"." + (i & 0xFF);
}
public String longToIp2(long ip) {
StringBuilder sb = new StringBuilder(15);
for (int i = 0; i < 4; i++) {
// 1. 2
// 2. 1
// 3. 168
// 4. 192
sb.insert(0, Long.toString(ip & 0xff));
if (i < 3) {
sb.insert(0, '.');
}
// 1. 192.168.1.2
// 2. 192.168.1
// 3. 192.168
// 4. 192
ip = ip >> 8;
}
return sb.toString();
}
}
conclusion
That is the end of this article on Java programming IP address and number conversion code examples, I hope to help you. Interested friends can continue to refer to other relevant topics in this site, if there is any deficiency, welcome to leave a message!