无法使用AsyncTask从html获取数据

<uses-permission android:name="android.permission.INTERNET"/>

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;

public class NetworkUtils {
    private ExecutorService executorService = Executors.newSingleThreadExecutor();

    public Future<String> fetchHtmlData(String urlString) {
        return executorService.submit(() -> {
            URL url = new URL(urlString);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("GET");

            BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            String inputLine;
            StringBuilder content = new StringBuilder();
            while ((inputLine = in.readLine()) != null) {
                content.append(inputLine);
            }
            in.close();
            connection.disconnect();
            return content.toString();
        });
    }

    public void shutdown() {
        executorService.shutdown();
    }
}

NetworkUtils networkUtils = new NetworkUtils();
Future<String> futureHtmlData = networkUtils.fetchHtmlData("http://example.com");

// 在 UI 线程中处理结果
new Thread(() -> {
    try {
        String htmlData = futureHtmlData.get();
        // 更新 UI
    } catch (Exception e) {
        e.printStackTrace();
    }
}).start();