android擷取ip

step1: 擷取權限 聯網

<uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE" />
    <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
           

String ipAddress2 = Utils.getIPAddress(true); // IPv4
                System.out.println(ipAddress2);
                Utils.getMACAddress("wlan0");
                Utils.getMACAddress("eth0");
                Utils.getIPAddress(true); // IPv4
                Utils.getIPAddress(false); // IPv6
           

package com.example.user.mathgame;

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 "";
    }

}