kotlin语言。

fun contextIP(context: Context): String {
    val wm: WifiManager = context.getSystemService(Context.WIFI_SERVICE) as WifiManager
    return Formatter.formatIpAddress(wm.connectionInfo.ipAddress)
}

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。

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());

根据我的测试，这是我的建议

import java.net.*;
import java.util.*;

public class hostUtil
{
   public static String HOST_NAME = null;
   public static String HOST_IPADDRESS = null;

   public static String getThisHostName ()
   {
      if (HOST_NAME == null) obtainHostInfo ();
      return HOST_NAME;
   }

   public static String getThisIpAddress ()
   {
      if (HOST_IPADDRESS == null) obtainHostInfo ();
      return HOST_IPADDRESS;
   }

   protected static void obtainHostInfo ()
   {
      HOST_IPADDRESS = "127.0.0.1";
      HOST_NAME = "localhost";

      try
      {
         InetAddress primera = InetAddress.getLocalHost();
         String hostname = InetAddress.getLocalHost().getHostName ();

         if (!primera.isLoopbackAddress () &&
             !hostname.equalsIgnoreCase ("localhost") &&
              primera.getHostAddress ().indexOf (':') == -1)
         {
            // Got it without delay!!
            HOST_IPADDRESS = primera.getHostAddress ();
            HOST_NAME = hostname;
            //System.out.println ("First try! " + HOST_NAME + " IP " + HOST_IPADDRESS);
            return;
         }
         for (Enumeration<NetworkInterface> netArr = NetworkInterface.getNetworkInterfaces(); netArr.hasMoreElements();)
         {
            NetworkInterface netInte = netArr.nextElement ();
            for (Enumeration<InetAddress> addArr = netInte.getInetAddresses (); addArr.hasMoreElements ();)
            {
               InetAddress laAdd = addArr.nextElement ();
               String ipstring = laAdd.getHostAddress ();
               String hostName = laAdd.getHostName ();

               if (laAdd.isLoopbackAddress()) continue;
               if (hostName.equalsIgnoreCase ("localhost")) continue;
               if (ipstring.indexOf (':') >= 0) continue;

               HOST_IPADDRESS = ipstring;
               HOST_NAME = hostName;
               break;
            }
         }
      } catch (Exception ex) {}
   }
}

最近，一个IP地址仍然由getLocalIpAddress()返回，尽管与网络断开连接(没有服务指示器)。说明“设置>关于话机>状态”中显示的IP地址与应用程序想象的不一致。

我之前已经通过添加以下代码实现了一个解决方案:

ConnectivityManager cm = getConnectivityManager();
NetworkInfo net = cm.getActiveNetworkInfo();
if ((null == net) || !net.isConnectedOrConnecting()) {
    return null;
}

有谁听过吗?

这里是@Nilesh和@anargund的kotlin版本

  fun getIpAddress(): String {
    var ip = ""
    try {
        val wm = applicationContext.getSystemService(WIFI_SERVICE) as WifiManager
        ip = Formatter.formatIpAddress(wm.connectionInfo.ipAddress)
    } catch (e: java.lang.Exception) {

    }

    if (ip.isEmpty()) {
        try {
            val en = NetworkInterface.getNetworkInterfaces()
            while (en.hasMoreElements()) {
                val networkInterface = en.nextElement()
                val enumIpAddr = networkInterface.inetAddresses
                while (enumIpAddr.hasMoreElements()) {
                    val inetAddress = enumIpAddr.nextElement()
                    if (!inetAddress.isLoopbackAddress && inetAddress is Inet4Address) {
                        val host = inetAddress.getHostAddress()
                        if (host.isNotEmpty()) {
                            ip =  host
                            break;
                        }
                    }
                }

            }
        } catch (e: java.lang.Exception) {

        }
    }

   if (ip.isEmpty())
      ip = "127.0.0.1"
    return ip
}