Android HttpUrlConnection Url无法在模拟器上运行

2 回答

• 0

  问题是我的计算机上的防病毒/防火墙 . 它阻止了我的连接，这就是为什么它在外部手机而不是模拟器上工作的原因 . 我禁用了我的防病毒/防火墙，它工作正常 . 这里有一个网络限制列表http://developer.android.com/tools/devices/emulator.html#networkinglimitations

  回复于 2024-05-03T04:09:03+08:00
• 1

  我刚刚在我的设备上尝试过该URL，但没有收到任何错误 . 这是我使用的代码 .

  一个返回UI线程的接口

  public interface AsyncResponse<T> {
      void onResponse(T response);
  }
  

  ---

  返回String的通用AsyncTask - 可以随意修改它以解析您的JSON并返回List .

  public class WebDownloadTask extends AsyncTask<String, Void, String> {
  
      private AsyncResponse<String> callback;
  
      public void setCallback(AsyncResponse<String> callback) {
          this.callback = callback;
      }
  
      @Override
      protected String doInBackground(String... params) {
          String url = params[0];
          return readFromUrl(url);
      }
  
      @Override
      protected void onPostExecute(String s) {
          super.onPostExecute(s);
          if (callback != null) {
              callback.onResponse(s);
          } else {
              Log.w(WebDownloadTask.class.getSimpleName(), "The response was ignored");
          }
      }
  
      private String streamToString(InputStream is) throws IOException {
  
          StringBuilder sb = new StringBuilder();
          BufferedReader rd = new BufferedReader(new InputStreamReader(is));
          String line;
          while ((line = rd.readLine()) != null) {
              sb.append(line);
          }
          return sb.toString();
      }
  
      private String readFromUrl(String myWebpage) {
  
          String response = null;
          HttpURLConnection urlConnection = null;
  
          try {
              URL url = new URL(myWebpage);
  
              urlConnection = (HttpURLConnection) url.openConnection();
  
              InputStream inputStream = urlConnection.getInputStream();
              if (inputStream != null) {
                  response = streamToString(inputStream);
                  inputStream.close();
              }
  
          } catch (IOException e) {
              e.printStackTrace();
          } finally {
              if (urlConnection != null) {
                  urlConnection.disconnect();
              }
          }
  
          return response;
      }
  }
  

  ---

  我的Activity部分调用AsyncTask .

  String url = "http://digitalcollections.tcd.ie/home/getMeta.php?pid=MS4418_021";
  
  WebDownloadTask task = new WebDownloadTask();
  task.setCallback(new AsyncResponse<String>() {
      @Override
      public void onResponse(String response) {
          Toast.makeText(getApplicationContext(), response, Toast.LENGTH_SHORT).show();
      }
  });
  task.execute(url);
  

  回复于 2024-05-03T04:09:03+08:00