无法读取Andoird O(Android8.0)中OkHttp中的响应

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

private class NetworkTask extends AsyncTask<Void, Void, String> {
    @Override
    protected String doInBackground(Void... params) {
        OkHttpClient client = new OkHttpClient();
        Request request = new Request.Builder()
                .url("http://example.com")
                .build();
        try {
            Response response = client.newCall(request).execute();
            return response.body().string();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(String result) {
        // 处理响应结果
        if (result != null) {
            // 在这里对响应进行处理
        }
    }
}

// 启动异步任务
new NetworkTask().execute();

implementation 'com.squareup.okhttp3:okhttp:版本号'

-dontwarn okhttp3.**
-keep class okhttp3.** { *; }
-dontwarn okio.**
-keep class okio.** { *; }