Java获取IPv4地址

Question

关于这个链接，使用提供的代码生成IP地址。

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地址的精确代码，但它提供了IPv4和IPv6地址。以下是生成的值。

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

(IPv6地址已隐藏)

我能不能只获取IPv4地址而不是两个地址都获取？

- Fouzy

Answer 1

您可以检查 addr 对象的类型，以确定它是 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);
}

- Alastair McCormack