java在linux获得ip地址和mac

以前在linux下获取ip和mac一般使用jni，调用linux的ioctl。当然也有使用shell获取的。
发现在jdk 6下已经实现了，java.net.NetworkInterface上面有静态方法可以获取到所有本地网卡信息。注意的是用Java的InetAddress.getLocalHost()方法在Linux下只能得到127.0.0.1，只能在Windows下获取正确的ip地址.
代码如下
package test;

import java.io.*;
import java.net.*;
import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import static java.lang.System.out;

public class ListNIFs
{
    public static void main(String args[]) throws SocketException {
        Enumeration nets = NetworkInterface.getNetworkInterfaces();
        
        for (NetworkInterface netIf : Collections.list(nets)) {
            String name =  netIf.getDisplayName();
            if(name.equals("eth0"))
            {
            out.printf("Display name: %s\n", netIf.getDisplayName());
            out.printf("Name: %s\n", netIf.getName());
            byte [] mac = netIf.getHardwareAddress();
            String macs =Hex.encodeHexStr(mac);
            out.printf("Name: %s\n", macs);
            //displaySubInterfaces(netIf);
            out.printf("\n");
            }
            
        }
        printHardwareAddresses();
    }
static void printHardwareAddresses() throws SocketException {
    if (System.getProperty("os.name").equals("Linux")) {

        // Read all available device names
        List devices = new ArrayList<>();
        Pattern pattern = Pattern.compile("^ *(.*):");
        try (FileReader reader = new FileReader("/proc/net/dev")) {
            BufferedReader in = new BufferedReader(reader);
            String line = null;
            while( (line = in.readLine()) != null) {
                Matcher m = pattern.matcher(line);
                if (m.find()) {
                    devices.add(m.group(1));
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }

        // read the hardware address for each device
        for (String device : devices) {
            try (FileReader reader = new FileReader("/sys/class/net/" + device + "/address")) {
                BufferedReader in = new BufferedReader(reader);
                String addr = in.readLine();

                System.out.println(String.format("%5s: %s", device, addr));
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

    } else {
        // use standard API for Windows & Others (need to test on each platform, though!!)
      
    }
}