尝试从newsapi.org获取数据，但最终出现403错误、未找到paramType 2048等

Question

NetworkUtilities.java

公共类NetworkUtilities{

private static final String TAG = NetworkUtilities.class.getSimpleName();

public static URL createUrl(String stringUrl){
    URL url = null;
    try{
        url = new URL(stringUrl);
    }catch (MalformedURLException e){
        Log.v(TAG, "Problem building the Url");
    }
    return url;
}


public static String httpRequest(URL url) throws IOException{
    String jsonResponse = "";
    if(url ==null){
        Log.v(TAG, "Url is null");
        return jsonResponse;
    }
    HttpURLConnection httpURLConnection = null;
    InputStream inputStream = null;
    try{
        httpURLConnection = (HttpURLConnection) url.openConnection();
        httpURLConnection.setReadTimeout(10000);
        httpURLConnection.setConnectTimeout(15000);
        httpURLConnection.setRequestMethod("GET");
        httpURLConnection.connect();

        if(httpURLConnection.getResponseCode() == 200){
            inputStream = httpURLConnection.getInputStream();
            jsonResponse = readFromStream(inputStream);
        }
        else{
            Log.e(TAG, "Error response code" + httpURLConnection.getResponseCode());
        }
    }catch (IOException e){
        Log.v(TAG, "Problem retrieving the json result", e);
    }finally {
        if(httpURLConnection != null){
            httpURLConnection.disconnect();
        }
        if(inputStream != null){
            inputStream.close();
        }
    }
    return jsonResponse;
}

private static String readFromStream(InputStream inputStream) throws IOException{
    StringBuilder output = new StringBuilder();
    if(inputStream != null){
        InputStreamReader in = new InputStreamReader(inputStream, Charset.forName("UTF-8"));
        BufferedReader bf = new BufferedReader(in);
        String line = bf.readLine();
        while(line != null){
            output.append(line);
            line = bf.readLine();
        }
    }
    return output.toString();
}

public static List<String> extractFromJson(String jsonResponse){
    if(TextUtils.isEmpty(jsonResponse)){
        return null;
    }
     List<String> newsStories = new ArrayList<>();
    try{
        JSONObject baseObj = new JSONObject(jsonResponse);
        JSONArray articlesArray = baseObj.getJSONArray("data");
        for(int i=0;i<articlesArray.length();i++){
            JSONObject currentArticle = articlesArray.getJSONObject(i);
            JSONObject source = currentArticle.getJSONObject("source");
            String sourceName = source.getString("name");
            String title = currentArticle.getString("title");
            String description = currentArticle.getString("description");
            String newsStory = "Source" + sourceName + "/n" + title + "/n" + description;
            newsStories.add(newsStory);
        }
    }catch (JSONException e){
        Log.e(TAG, " Problem parsing the json string", e);
    }
    return newsStories;
}

NewsAdapter.java

公共类NewsAdapter扩展RecyclerView.Adapter {

private Context mContext;
private List<String> mNewsArticles;
NewsAdapter(Context context){
    mContext = context;
}

@NonNull
@Override
public NewsViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    View view = LayoutInflater
            .from(mContext)
            .inflate(R.layout.news_list_item,parent, false);
    view.setFocusable(true);
    return new NewsViewHolder(view);
}

@Override
public void onBindViewHolder( NewsViewHolder holder, int position) {
    String currentArticle = mNewsArticles.get(position);
    holder.mTextView.setText(currentArticle);
}

@Override
public int getItemCount() {
    if(mNewsArticles != null){
        return mNewsArticles.size();
    }
    return 0;
}


public class NewsViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
    final TextView mTextView;

    public NewsViewHolder(@NonNull View itemView) {
        super(itemView);
        mTextView = (TextView) itemView.findViewById(R.id.textView);
        itemView.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        Toast.makeText(v.getContext(), "position :" + getLayoutPosition(), Toast.LENGTH_SHORT).show();
    }
}
 public void setNewsData(List<String> newsData){
    mNewsArticles = newsData;
    notifyDataSetChanged();
 }

mainactivity.java

公共类MainActivity扩展AppCompatActivity{

private static final String TAG = MainActivity.class.getSimpleName();
private RecyclerView mRecyclerView;
private NewsAdapter mNewsAdapter;
private static final String BASE_URL = "https://newsapi.org/v2/top-headlines?country=us&apiKey=13f428d687714c33a24f34ad6c5***87";

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

mRecyclerView = (RecyclerView) findViewById(R.id.recycler_view);
mRecyclerView.setLayoutManager(
        new LinearLayoutManager(this,LinearLayoutManager.VERTICAL,false));
mRecyclerView.setHasFixedSize(true);
mNewsAdapter = new NewsAdapter(this);
mRecyclerView.setAdapter(mNewsAdapter);

new FetchNewsArticle().execute(BASE_URL);
}

public class FetchNewsArticle extends AsyncTask<String, Void, List<String>>{

    @Override
    protected List<String> doInBackground(String... strings) {
        String stringUrl = strings[0];
        URL url = NetworkUtilities.createUrl(stringUrl);
        String json = "";
        try{
            json = NetworkUtilities.httpRequest(url);
            List<String> articles = NetworkUtilities.extractFromJson(json);
            return articles;
        }catch (Exception e){
            e.printStackTrace();
            Log.v(TAG, "Problem retrieving data");
            return null;
        }

    }

    @Override
    protected void onPostExecute(List<String> strings) {
        if(strings != null){
         mNewsAdapter.setNewsData(strings);
        }
    }
}

错误

w/zygote：无法打开libbeluga.so：dlopen失败：找不到库“libbeluga.so”。d/networksecurityconfig：未指定网络安全配置，使用平台默认值d/networksecurityconfig：未指定网络安全配置，使用平台默认值w/xample.newsfee：访问隐藏方法landroid/view/view；>ComputeFitSystemWindows（Landroid/Graphics/rect；Landroid/Graphics/rect；）Z（greylist,reflection,allowed）w/xample.newsFeed：访问隐藏方法Landroid/View/ViewGroup；->MakeOptionalFitsSystemWindows（）V（greylist,reflection,allowed）com.example.newsFeed V/NetworkUtilities：检索json结果的问题

java.io.ioException：com.android.okhttp.httpandler$cleartexturlfilter.checkurlpermitt(httpandler.java:127)在com.android.okhttp.internal.huc.httpurlconnectionimpl.execute(httpurlconnectionimpl.java:462)在com.android.okhttp.internal.huc.httpurlconnectionimpl.connect(httpurlconnectionimpl.java:131)在com.example.newsfeed.utils.networkutilities.httprequest（thread.java：923）2021-03-11 22:53:28.124 939 1-9391/com.example.newsfeed w/looper：PerfMonitor looperActivity:package=com.example.newsfeed/.mainactivity time=1ms latency=447ms running=2ms procstate=2 ClientTransaction{callbacks=[android.app.servertransaction.topresumedactivitychangeitem]}historymsgcount=4(msgindex=3 wall=87ms seq=3le.newsfeed I/adrenogles-0:驱动程序路径：/vendor/lib64/egl/libglesv2_adreno.so 2021-03-11 22:53:28.213 939 1-9429/com.example.newsfeed I/adrenogles-0:pfp:0x016EE190,ME:0x00000000 2021-03-11 22:53:28.253 939 1-9429/com.example.newsfeed E/lb：无法打开文件：没有这样的文件或目录

Answer 1

错误似乎是:java.io.IOException：不允许到api.mediastack.com的明文HTTP通信。

从Android 9开始，默认禁用明文http通信。

请查看官方的Android文档，以及这个问题以获取更多的信息。