有效的方法来检查慢速互联网连接，并区分网络连接和Android中的实际互联网连接

2 回答

• 0

  如果您想知道何时有有效的互联网连接，请执行以下操作：

  一些静态变量：

  /**
   * Set the number of retries when reestablishing Internet connection.
   */
  private static int retryConnectionNumber = 0;
  
  /**
   * The maximum number of retries allowed for Internet connection.
   */
  private final static int CONNECTION_RETRY_MAX = 5;
  
  /**
   * The timeout of the HTTP request when checking for Internet connection.
   */
  private final static int REQUEST_TIMEOUT = 2000;
  

  检查网络是否可用的方法：

  private static void isNetworkAvailable(final Handler handler,
              final int timeout) {
          new Thread() {
              private boolean responded = false;
  
              @Override
              public void run() {
                  URL url = null;
                  try {
                      url = new URL("http://your_server_addres.com");
                  } catch (MalformedURLException e1) {
                      e1.printStackTrace();
                  }
                  String host = "";
                  if (null != url) {
                      host = url.getHost();
                  }
  
                  Log.i("NetworkCheck", "[PING] host: " + host);
                  Process process = null;
                  try {
                      process = new ProcessBuilder()
                              .command("/system/bin/ping", "-c 1",
                                      "-w " + (timeout / 1000), "-n", host)
                              .redirectErrorStream(true).start();
                  } catch (IOException e) {
                      e.printStackTrace();
                  }
  
                  InputStream in = process.getInputStream();
                  StringBuilder s = new StringBuilder();
                  int i;
  
                  try {
                      while ((i = in.read()) != -1) {
                          s.append((char) i);
  
                          if ((char) i == '\n') {
                              Log.i("NetworkCheck",
                                      "[PING] log: " + s.toString());
                              if (s.toString().contains("64 bytes from")) {
                                  // If there were a response from the server at
                                  // all, we have Internet access
                                  responded = true;
                              }
                              s.delete(0, s.length());
                          }
                      }
                  } catch (IOException e) {
                      e.printStackTrace();
                  } finally {
                      // Destroy the PING process
                      process.destroy();
  
                      try {
                          // Close the input stream - avoid memory leak
                          in.close();
                      } catch (IOException e) {
                          e.printStackTrace();
                      }
  
                      // Send the response to the handler, 1 for success, 0
                      // otherwise
                      handler.sendEmptyMessage(!responded ? 0 : 1);
                  }
              }
          }.start();
      }
  

  处理程序：

  /**
   * Handler used that receives the connection status for the Internet.
   * If no active Internet connection will retry #CONNECTION_RETRY_MAX times
   */
  private static Handler listenForNetworkAvailability = new Handler() {
      @Override
      public void handleMessage(Message msg) {
          if (msg.what != 1) { // code if not connected
              Log.i("NetworkCheck", "not connected");
  
              if (retryConnectionNumber <= CONNECTION_RETRY_MAX) {
                  Log.i("NetworkCheck", "checking for connectivity");
                  Here you could disable & re-enable your WIFI/3G connection before retry
  
                  // Start the ping process again with delay
                  Handler handler = new Handler();
                  handler.postDelayed(new Runnable() {
                      @Override
                      public void run() {
                          isNetworkAvailable(listenForNetworkAvailability, REQUEST_TIMEOUT);
                      }
                  }, 5000);
                  retryConnectionNumber++;
              } else {
                  Log.i("NetworkCheck", "failed to establish an connection");
                  // code if not connected
              }
          } else {            
              Log.i("NetworkCheck", "connected");
              retryConnectionNumber = 0;
              // code if connected
          }
      }
  }
  

  回复于 2024-04-29T22:30:17+08:00
• 1

  像这样的东西会起作用：

  private boolean haveNetworkConnection() {
          boolean haveConnectedWifi = false;
          boolean haveConnectedMobile = false;
  
          ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
          NetworkInfo[] netInfo = cm.getAllNetworkInfo();
          for (NetworkInfo ni : netInfo) {
              if (ni.getTypeName().equalsIgnoreCase("WIFI"))
                  if (ni.isConnected())
                      haveConnectedWifi = true;
              if (ni.getTypeName().equalsIgnoreCase("MOBILE"))
                  if (ni.isConnected())
                      haveConnectedMobile = true;
          }
          return haveConnectedWifi || haveConnectedMobile;
      }
  

  我已经从here复制了这段代码（我理解代码 - 我只是在这里添加代码，以方便管理员告诉用户你应该这样做，并归功于原帖） . 我个人会把它分成两个功能，一个用于移动，一个用于wifi，但这个选择取决于你 .

  回复于 2024-04-29T22:30:17+08:00