在应用调试过程中，对接的技术人员要求提供一下机顶盒 的外网IP地址，于是打开了盒子上的设置，将IP地址发了过去，对面回复说这是私网IP，要公网IP才可以。
一般情况下，电脑的公网IP地址很好查：打开百度：
但是有些机顶盒上是没有浏览器的，所以就需要通过代码的层面来获取。
通过百度，先找到了如下的方法：
/** * 获取IP地址 * @return * @throws SocketException */ public static String getLocalIPAddress() throws SocketException { for(Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements();){ NetworkInterface intf = en.nextElement(); for(Enumeration<InetAddress> enumIpAddr = intf.getInetAddresses(); enumIpAddr.hasMoreElements();){ InetAddress inetAddress = enumIpAddr.nextElement(); if(!inetAddress.isLoopbackAddress() && (inetAddress instanceof Inet4Address)){ return inetAddress.getHostAddress().toString(); } } } return "null"; }但是获取到的结果和机顶盒设置里的ip一致的，也就是说还是一个私网IP。
后经过查询，可通过如下方式获取公网IP：
/** * 获取外网IP地址 * @return */ public static String GetNetIp(){ String IP = ""; try { String address = "http://ip.taobao.com/service/getIpInfo2.php?ip=myip"; URL url = new URL(address); //URLConnection htpurl=url.openConnection(); HttpURLConnection connection = (HttpURLConnection) url .openConnection(); connection.setUseCaches(false); connection.setRequestMethod("GET"); connection.setRequestProperty("user-agent", "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.7 Safari/537.36"); //设置浏览器ua 保证不出现503 if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) { InputStream in = connection.getInputStream(); // 将流转化为字符串 BufferedReader reader = new BufferedReader( new InputStreamReader(in)); String tmpString = ""; StringBuilder retJSON = new StringBuilder(); while ((tmpString = reader.readLine()) != null) { retJSON.append(tmpString + "n"); } JSONObject jsonObject = new JSONObject(retJSON.toString()); String code = jsonObject.getString("code"); if (code.equals("0")) { JSONObject data = jsonObject.getJSONObject("data"); IP = data.getString("ip") + "(" + data.getString("country") + data.getString("area") + "区" + data.getString("region") + data.getString("city") + data.getString("isp") + ")"; Log.e("提示", "您的IP地址是：" + IP); } else { IP = ""; Log.e("提示", "IP接口异常，无法获取IP地址！"); } } else { IP = ""; Log.e("提示", "网络连接异常，无法获取IP地址！"); } } catch (Exception e) { IP = ""; Log.e("提示", "获取IP地址时出现异常，异常信息是：" + e.toString()); } return IP; }在代码中调用：
try { String localIPAddress = IPutils.getLocalIPAddress(); LogUtil.Log_i("IP地址："+localIPAddress); } catch (SocketException e) { e.printStackTrace(); } new Thread(new Runnable() { @Override public void run() { String s = IPutils.GetNetIp(); LogUtil.Log_i("外网IP："+s); } }).start();获取到的结果：
外网IP：221.220.160.241(中国区北京北京联通)
这说明是成功的。需要注意的是，获取外网IP的方法必须要在子线程中执行。
附完整的工具类：
package com.zyp.river.utils;import android.util.Log;import org.json.JSONObject;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.net.HttpURLConnection;import java.net.Inet4Address;import java.net.InetAddress;import java.net.MalformedURLException;import java.net.NetworkInterface;import java.net.SocketException;import java.net.URL;import java.net.URLConnection;import java.util.Enumeration;/** * Created by ZhangYanPeng on 2018/9/19. */public class IPutils { /** * 获取IP地址 * @return * @throws SocketException */ public static String getLocalIPAddress() throws SocketException { for(Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements();){ NetworkInterface intf = en.nextElement(); for(Enumeration<InetAddress> enumIpAddr = intf.getInetAddresses(); enumIpAddr.hasMoreElements();){ InetAddress inetAddress = enumIpAddr.nextElement(); if(!inetAddress.isLoopbackAddress() && (inetAddress instanceof Inet4Address)){ return inetAddress.getHostAddress().toString(); } } } return "null"; } /** * 获取外网IP地址 * @return */ public static String GetNetIp(){ String IP = ""; try { String address = "http://ip.taobao.com/service/getIpInfo2.php?ip=myip"; URL url = new URL(address); //URLConnection htpurl=url.openConnection(); HttpURLConnection connection = (HttpURLConnection) url .openConnection(); connection.setUseCaches(false); connection.setRequestMethod("GET"); connection.setRequestProperty("user-agent", "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.7 Safari/537.36"); //设置浏览器ua 保证不出现503 if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) { InputStream in = connection.getInputStream(); // 将流转化为字符串 BufferedReader reader = new BufferedReader( new InputStreamReader(in)); String tmpString = ""; StringBuilder retJSON = new StringBuilder(); while ((tmpString = reader.readLine()) != null) { retJSON.append(tmpString + "n"); } JSONObject jsonObject = new JSONObject(retJSON.toString()); String code = jsonObject.getString("code"); if (code.equals("0")) { JSONObject data = jsonObject.getJSONObject("data"); IP = data.getString("ip") + "(" + data.getString("country") + data.getString("area") + "区" + data.getString("region") + data.getString("city") + data.getString("isp") + ")"; Log.e("提示", "您的IP地址是：" + IP); } else { IP = ""; Log.e("提示", "IP接口异常，无法获取IP地址！"); } } else { IP = ""; Log.e("提示", "网络连接异常，无法获取IP地址！"); } } catch (Exception e) { IP = ""; Log.e("提示", "获取IP地址时出现异常，异常信息是：" + e.toString()); } return IP; }}