SocketTimeoutException等待但不被拋出？

Question

我正在寫一個接收服務器數據的Android應用程序。理論上可能沒有互聯網連接，所以我嘗試通過捕獲SocketTimeoutException來顯示錯誤消息，重試屏幕或其他內容來捕獲此案例。不幸的是，這個異常不會被拋出。至少它不會跳入catch子句。我究竟做錯了什麼？

public class HttpConnector { 

    private String urlString; 
    private int connectionTimeout = 5000; //milliseconds 

    public HttpConnector(String urlString) { 
     this.urlString = urlString; 
    } 

    public String receiveData() throws PolizeiwarnungException { 
     URL url = null; 
     HttpURLConnection urlConnection = null; 
     StringBuffer b = new StringBuffer(); 

     try { 
      url = new URL(urlString); 
      urlConnection = (HttpURLConnection) url.openConnection(); 
      urlConnection.setReadTimeout(connectionTimeout); 
      BufferedReader reader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream())); //Here it gets stuck if there is no connection to the server 

      String str; 
      while ((str = reader.readLine()) != null) { 
       b.append(str + "\n"); 
      } 
     } 
     catch (SocketTimeoutException e) { 
      //TODO 
      e.printStackTrace(); 
     } 
     catch (IOException e) { 
      throw new PolizeiwarnungException(e); 
     } 
     finally { 
      if (urlConnection != null) { 
       urlConnection.disconnect(); 
      } 
     } 

     return b.toString(); 
    } 

    public void sendData(String data) { 
     //TODO 
    } 
} 

Answer 1

您還需要設置連接超時。 Please see this documentation.

由於終點不存在，所以沒有設置連接超時，連接永遠不會超時。

setConnectTimeout（INT超時）設置建立由 此URLConnection實例指出了資源的連接毫秒 的超時值。