手机无法解析域名

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.Network;
import android.net.NetworkCapabilities;
import android.net.NetworkRequest;
import android.os.Bundle;
import android.util.Log;
import androidx.appcompat.app.AppCompatActivity;
import java.net.InetAddress;
import java.net.UnknownHostException;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // 设置DNS服务器
        setDnsServer("8.8.8.8");

        // 测试DNS解析
        testDnsResolution("www.example.com");
    }

    private void setDnsServer(String dnsServer) {
        try {
            InetAddress inetAddress = InetAddress.getByName(dnsServer);
            ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkRequest.Builder builder = new NetworkRequest.Builder();
            connectivityManager.registerNetworkCallback(builder.build(), new ConnectivityManager.NetworkCallback() {
                @Override
                public void onAvailable(Network network) {
                    super.onAvailable(network);
                    Log.d("DNS", "Network available");
                }
            });
        } catch (UnknownHostException e) {
            Log.e("DNS", "Invalid DNS server address", e);
        }
    }

    private void testDnsResolution(String domain) {
        new Thread(() -> {
            try {
                InetAddress[] addresses = InetAddress.getAllByName(domain);
                for (InetAddress address : addresses) {
                    Log.d("DNS", "Resolved IP: " + address.getHostAddress());
                }
            } catch (UnknownHostException e) {
                Log.e("DNS", "DNS resolution failed", e);
            }
        }).start();
    }
}