这是我的助手util读取IP和MAC地址。实现是纯java，但我在getMACAddress()中有一个注释块，可以从特殊的Linux(Android)文件读取值。我只在少数设备和模拟器上运行了这段代码，但如果你发现奇怪的结果，请告诉我。

// AndroidManifest.xml permissions
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

// test functions
Utils.getMACAddress("wlan0");
Utils.getMACAddress("eth0");
Utils.getIPAddress(true); // IPv4
Utils.getIPAddress(false); // IPv6 

Utils.java

import java.io.*;
import java.net.*;
import java.util.*;   
//import org.apache.http.conn.util.InetAddressUtils;

public class Utils {

    /**
     * Convert byte array to hex string
     * @param bytes toConvert
     * @return hexValue
     */
    public static String bytesToHex(byte[] bytes) {
        StringBuilder sbuf = new StringBuilder();
        for(int idx=0; idx < bytes.length; idx++) {
            int intVal = bytes[idx] & 0xff;
            if (intVal < 0x10) sbuf.append("0");
            sbuf.append(Integer.toHexString(intVal).toUpperCase());
        }
        return sbuf.toString();
    }

    /**
     * Get utf8 byte array.
     * @param str which to be converted
     * @return  array of NULL if error was found
     */
    public static byte[] getUTF8Bytes(String str) {
        try { return str.getBytes("UTF-8"); } catch (Exception ex) { return null; }
    }

    /**
     * Load UTF8withBOM or any ansi text file.
     * @param filename which to be converted to string
     * @return String value of File
     * @throws java.io.IOException if error occurs
     */
    public static String loadFileAsString(String filename) throws java.io.IOException {
        final int BUFLEN=1024;
        BufferedInputStream is = new BufferedInputStream(new FileInputStream(filename), BUFLEN);
        try {
            ByteArrayOutputStream baos = new ByteArrayOutputStream(BUFLEN);
            byte[] bytes = new byte[BUFLEN];
            boolean isUTF8=false;
            int read,count=0;           
            while((read=is.read(bytes)) != -1) {
                if (count==0 && bytes[0]==(byte)0xEF && bytes[1]==(byte)0xBB && bytes[2]==(byte)0xBF ) {
                    isUTF8=true;
                    baos.write(bytes, 3, read-3); // drop UTF8 bom marker
                } else {
                    baos.write(bytes, 0, read);
                }
                count+=read;
            }
            return isUTF8 ? new String(baos.toByteArray(), "UTF-8") : new String(baos.toByteArray());
        } finally {
            try{ is.close(); } catch(Exception ignored){} 
        }
    }

    /**
     * Returns MAC address of the given interface name.
     * @param interfaceName eth0, wlan0 or NULL=use first interface 
     * @return  mac address or empty string
     */
    public static String getMACAddress(String interfaceName) {
        try {
            List<NetworkInterface> interfaces = Collections.list(NetworkInterface.getNetworkInterfaces());
            for (NetworkInterface intf : interfaces) {
                if (interfaceName != null) {
                    if (!intf.getName().equalsIgnoreCase(interfaceName)) continue;
                }
                byte[] mac = intf.getHardwareAddress();
                if (mac==null) return "";
                StringBuilder buf = new StringBuilder();
                for (byte aMac : mac) buf.append(String.format("%02X:",aMac));  
                if (buf.length()>0) buf.deleteCharAt(buf.length()-1);
                return buf.toString();
            }
        } catch (Exception ignored) { } // for now eat exceptions
        return "";
        /*try {
            // this is so Linux hack
            return loadFileAsString("/sys/class/net/" +interfaceName + "/address").toUpperCase().trim();
        } catch (IOException ex) {
            return null;
        }*/
    }

    /**
     * Get IP address from first non-localhost interface
     * @param useIPv4   true=return ipv4, false=return ipv6
     * @return  address or empty string
     */
    public static String getIPAddress(boolean useIPv4) {
        try {
            List<NetworkInterface> interfaces = Collections.list(NetworkInterface.getNetworkInterfaces());
            for (NetworkInterface intf : interfaces) {
                List<InetAddress> addrs = Collections.list(intf.getInetAddresses());
                for (InetAddress addr : addrs) {
                    if (!addr.isLoopbackAddress()) {
                        String sAddr = addr.getHostAddress();
                        //boolean isIPv4 = InetAddressUtils.isIPv4Address(sAddr);
                        boolean isIPv4 = sAddr.indexOf(':')<0;

                        if (useIPv4) {
                            if (isIPv4) 
                                return sAddr;
                        } else {
                            if (!isIPv4) {
                                int delim = sAddr.indexOf('%'); // drop ip6 zone suffix
                                return delim<0 ? sAddr.toUpperCase() : sAddr.substring(0, delim).toUpperCase();
                            }
                        }
                    }
                }
            }
        } catch (Exception ignored) { } // for now eat exceptions
        return "";
    }

}

免责声明:这个Utils类的想法和示例代码来自 几个SO帖子和谷歌。我已经清理和合并了所有的例子。

Kotlin极简版

fun getIpv4HostAddress(): String {
    NetworkInterface.getNetworkInterfaces()?.toList()?.map { networkInterface ->
        networkInterface.inetAddresses?.toList()?.find {
            !it.isLoopbackAddress && it is Inet4Address
        }?.let { return it.hostAddress }
    }
    return ""
}

这是这个答案的返工，去掉了不相关的信息，添加了有用的评论，更清楚地命名变量，并改进了逻辑。

不要忘记包含以下权限:

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

InternetHelper.java:

public class InternetHelper {

    /**
     * Get IP address from first non-localhost interface
     *
     * @param useIPv4 true=return ipv4, false=return ipv6
     * @return address or empty string
     */
    public static String getIPAddress(boolean useIPv4) {
        try {
            List<NetworkInterface> interfaces =
                    Collections.list(NetworkInterface.getNetworkInterfaces());

            for (NetworkInterface interface_ : interfaces) {

                for (InetAddress inetAddress :
                        Collections.list(interface_.getInetAddresses())) {

                    /* a loopback address would be something like 127.0.0.1 (the device
                       itself). we want to return the first non-loopback address. */
                    if (!inetAddress.isLoopbackAddress()) {
                        String ipAddr = inetAddress.getHostAddress();
                        boolean isIPv4 = ipAddr.indexOf(':') < 0;

                        if (isIPv4 && !useIPv4) {
                            continue;
                        }
                        if (useIPv4 && !isIPv4) {
                            int delim = ipAddr.indexOf('%'); // drop ip6 zone suffix
                            ipAddr = delim < 0 ? ipAddr.toUpperCase() :
                                    ipAddr.substring(0, delim).toUpperCase();
                        }
                        return ipAddr;
                    }
                }

            }
        } catch (Exception ignored) { } // if we can't connect, just return empty string
        return "";
    }

    /**
     * Get IPv4 address from first non-localhost interface
     *
     * @return address or empty string
     */
    public static String getIPAddress() {
        return getIPAddress(true);
    }

}

如果你有一个壳;Ifconfig eth0也适用于x86设备

在Kotlin中，没有Formatter

private fun getIPAddress(useIPv4 : Boolean): String {
    try {
        var interfaces = Collections.list(NetworkInterface.getNetworkInterfaces())
        for (intf in interfaces) {
            var addrs = Collections.list(intf.getInetAddresses());
            for (addr in addrs) {
                if (!addr.isLoopbackAddress()) {
                    var sAddr = addr.getHostAddress();
                    var isIPv4: Boolean
                    isIPv4 = sAddr.indexOf(':')<0
                    if (useIPv4) {
                        if (isIPv4)
                            return sAddr;
                    } else {
                        if (!isIPv4) {
                            var delim = sAddr.indexOf('%') // drop ip6 zone suffix
                            if (delim < 0) {
                                return sAddr.toUpperCase()
                            }
                            else {
                                return sAddr.substring(0, delim).toUpperCase()
                            }
                        }
                    }
                }
            }
        }
    } catch (e: java.lang.Exception) { }
    return ""
}

在AndroidManifest.xml中声明ACCESS_WIFI_STATE权限:

<uses-permission
    android:name="android.permission.ACCESS_WIFI_STATE"/>

可以通过WifiManager获取IP地址:

Context context = requireContext().getApplicationContext();
WifiManager wm = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
String ip = Formatter.formatIpAddress(wm.getConnectionInfo().getIpAddress());