java判断ipv6 在同一网段函数

以下是一个判断IPv6在同一网段的函数示例，使用Java语言实现：

import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.UnknownHostException;

public class IPv6Utils {

    public static boolean isInSameSubnet(String ip1, String ip2, int prefixLength) {
        try {
            InetAddress inetAddress1 = InetAddress.getByName(ip1);
            InetAddress inetAddress2 = InetAddress.getByName(ip2);
            
            if (inetAddress1 instanceof Inet6Address && inetAddress2 instanceof Inet6Address) {
                byte[] bytes1 = inetAddress1.getAddress();
                byte[] bytes2 = inetAddress2.getAddress();
                
                // 检查前缀长度是否合法
                if (prefixLength <= 0 || prefixLength > bytes1.length * 8) {
                    return false;
                }
                
                // 计算需要比较的字节数
                int byteCount = prefixLength / 8;
                int bitCount = prefixLength % 8;
                if (bitCount > 0) {
                    byteCount++;
                }
                
                // 比较前缀部分
                for (int i = 0; i < byteCount; i++) {
                    if (bytes1[i] != bytes2[i]) {
                        return false;
                    }
                }
                
                return true;
            }
        } catch (UnknownHostException e) {
            e.printStackTrace();
        }
        
        return false;
    }

}

使用示例：

String ip1 = "2001:db8:abcd:1234::1";
String ip2 = "2001:db8:abcd:1234::2";
int prefixLength = 64;
boolean result = IPv6Utils.isInSameSubnet(ip1, ip2, prefixLength);
System.out.println(result); // 输出 true

在此示例中，IPv6地址`2001:db8:abcd:1234::1`和`2001:db8:abcd:1234::2`具有相同的前64位，因此它们在同一网络中。函数返回`true`表示它们在同一子网中。