核心原理
可以通过给
https://ipinfo.io/ip
发送一个请求，这个会解析请求头里的数据，并将其ip解析出来返回到body数据里，这样前端页面拿到这个数据显示出来就可以知道自己设备联网的公网ip地址了。
Android客户端代码
引入okhttp的依赖
implementation 'com.squareup.okhttp3:okhttp:4.9.1'
Java代码
import android.annotation.SuppressLint;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.text.TextUtils;
import android.util.Log;
import android.view.View;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;public class MainActivity extends AppCompatActivity {private TextView ipTextView;private Handler mainHandler;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);ipTextView = findViewById(R.id.ipTextView);// 创建一个主线程的 Handler，接收并处理子线程发送的消息mainHandler = new Handler(Looper.getMainLooper()) {@Overridepublic void handleMessage(Message msg) {super.handleMessage(msg);// 处理消息if (msg.what == 1) {String publicIp = (String) msg.obj; // 获取传递过来的公网 IPipTextView.setText("Public IP: " + publicIp); // 更新 UI}}};findViewById(R.id.btnGetPublicIP).setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {// 启动子线程进行网络请求new Thread(new Runnable() {@SuppressLint("SetTextI18n")@Overridepublic void run() {String ip = getIp();if (!TextUtils.isEmpty(ip)) {// 子线程发送消息到主线程Message msg = mainHandler.obtainMessage();msg.what = 1; // 消息标识msg.obj = ip; // 传递结果mainHandler.sendMessage(msg); // 发送消息到主线程}}}).start();}});}public String getIp() {String ip = "";OkHttpClient okHttpClient = new OkHttpClient();Request request = new Request.Builder().url("https://ipinfo.io/ip").build();try {Response response = okHttpClient.newCall(request).execute();if (response.isSuccessful()) {if (response.body() != null) {String requestBody = response.body().string();Log.i("MainActivity", "requestBody length is " + requestBody.length());ip = requestBody;return ip;}}} catch (Exception e) {Log.e("MainActivity", "ipAddress is null exception is " + e);}return ip;}
}
引入布局文件
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"android:layout_width="match_parent"android:layout_height="match_parent"android:padding="16dp"><Buttonandroid:id="@+id/btnGetPublicIP"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="Get Public IP"android:layout_alignParentTop="true"/><TextViewandroid:id="@+id/ipTextView"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="Public IP will be shown here"android:layout_below="@id/btnGetPublicIP"android:layout_marginTop="16dp"/>
</RelativeLayout>
运行结果
