网络interface参数

您可以访问有关网络interface的网络参数，而不是为其分配的名称和 IP 地址

您可以使用isUP()方法发现网络interface是否“启动”(即正在运行)。下列方法指示网络interface类型：

• isLoopback()指示网络interface是否为回送interface。

• isPointToPoint()表示该interface是否为点对点interface。

• isVirtual()指示interface是否为虚拟interface。

supportsMulticast()方法指示网络interface是否支持多播。 getHardwareAddress()方法返回网络interface的物理硬件地址(通常称为 MAC 地址)(如果可用)。 getMTU()方法返回最大传输单元(MTU)，它是最大的数据包大小。

以下示例通过添加此页面上描述的其他网络参数来扩展列出网络interface地址中的示例：

import java.io.*;
import java.net.*;
import java.util.*;
import static java.lang.System.out;

public class ListNetsEx {

    public static void main(String args[]) throws SocketException {
        Enumeration<NetworkInterface> nets = NetworkInterface.getNetworkInterfaces();
        for (NetworkInterface netint : Collections.list(nets))
            displayInterfaceInformation(netint);
    }

    static void displayInterfaceInformation(NetworkInterface netint) throws SocketException {
        out.printf("Display name: %s\n", netint.getDisplayName());
        out.printf("Name: %s\n", netint.getName());
        Enumeration<InetAddress> inetAddresses = netint.getInetAddresses();
        
        for (InetAddress inetAddress : Collections.list(inetAddresses)) {
            out.printf("InetAddress: %s\n", inetAddress);
        }
       
        out.printf("Up? %s\n", netint.isUp());
        out.printf("Loopback? %s\n", netint.isLoopback());
        out.printf("PointToPoint? %s\n", netint.isPointToPoint());
        out.printf("Supports multicast? %s\n", netint.supportsMulticast());
        out.printf("Virtual? %s\n", netint.isVirtual());
        out.printf("Hardware address: %s\n",
                    Arrays.toString(netint.getHardwareAddress()));
        out.printf("MTU: %s\n", netint.getMTU());
        out.printf("\n");
     }
}

以下是示例程序的输出示例：

Display name: bge0
Name: bge0
InetAddress: /fe80:0:0:0:203:baff:fef2:e99d%2
InetAddress: /129.156.225.59
Up? true
Loopback? false
PointToPoint? false
Supports multicast? false
Virtual? false
Hardware address: [0, 3, 4, 5, 6, 7]
MTU: 1500

Display name: lo0
Name: lo0
InetAddress: /0:0:0:0:0:0:0:1%1
InetAddress: /127.0.0.1
Up? true
Loopback? true
PointToPoint? false
Supports multicast? false
Virtual? false
Hardware address: null
MTU: 8232