Java获取IPv4地址

Question

关于使用提供的代码生成IP地址的链接。

String ip;
    try {
       Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
        while (interfaces.hasMoreElements()) {
            NetworkInterface iface = interfaces.nextElement();
            // filters out 127.0.0.1 and inactive interfaces
            if (iface.isLoopback() || !iface.isUp())
                continue;

            Enumeration<InetAddress> addresses = iface.getInetAddresses();
            while(addresses.hasMoreElements()) {
                InetAddress addr = addresses.nextElement();
                ip = addr.getHostAddress();
                System.out.println(iface.getDisplayName() + " " + ip);
            }
        }
    } catch (SocketException e) {
        throw new RuntimeException(e);
    }

我已经实现了获取IP地址的确切代码，但它同时提供了IPv4和IPv6地址。下面是产生的价值。

Qualcomm Atheros AR5BWB222 Wireless Network Adapter 192.168.1.5
Qualcomm Atheros AR5BWB222 Wireless Network Adapter fe80:0:0:0:a874:xxxx:xxxx:9150%wlan0

（已编辑IPv6地址）

有没有办法只获取IPv4值而不同时获取两者？

Answer 1

您可以检查addr对象的类型，查看它是Inet4Address还是Inet6Address实例。

例如：

String ip;
try {
    Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
    while (interfaces.hasMoreElements()) {
        NetworkInterface iface = interfaces.nextElement();
        // filters out 127.0.0.1 and inactive interfaces
        if (iface.isLoopback() || !iface.isUp())
            continue;

        Enumeration<InetAddress> addresses = iface.getInetAddresses();
        while(addresses.hasMoreElements()) {
            InetAddress addr = addresses.nextElement();

            // *EDIT*
            if (addr instanceof Inet6Address) continue;

            ip = addr.getHostAddress();
            System.out.println(iface.getDisplayName() + " " + ip);
        }
    }
} catch (SocketException e) {
    throw new RuntimeException(e);
}