如何检查Android上的互联网接入?InetAddress从不超时

我得到了一个AsyncTask，应该检查对主机名的网络访问。但是doInBackground()永远不会超时。有人知道吗?

public class HostAvailabilityTask extends AsyncTask<String, Void, Boolean> {

    private Main main;

    public HostAvailabilityTask(Main main) {
        this.main = main;
    }

    protected Boolean doInBackground(String... params) {
        Main.Log("doInBackground() isHostAvailable():"+params[0]);

        try {
            return InetAddress.getByName(params[0]).isReachable(30); 
        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return false;       
    }

    protected void onPostExecute(Boolean... result) {
        Main.Log("onPostExecute()");

        if(result[0] == false) {
            main.setContentView(R.layout.splash);
            return;
        }

        main.continueAfterHostCheck();
    }   
}

当前回答

Jetpack组成/芬兰湾的科特林

根据Levite的回答，我们可以在Jetpack Compose中使用这个组合:

val DNS_SERVERS = listOf("8.8.8.8", "1.1.1.1", "4.2.2.4")
const val INTERNET_CHECK_DELAY = 3000L
@Composable
fun InternetAwareComposable(
    dnsServers: List<String> = DNS_SERVERS,
    delay: Long = INTERNET_CHECK_DELAY,
    successContent: (@Composable () -> Unit)? = null,
    errorContent: (@Composable () -> Unit)? = null,
    onlineChanged: ((Boolean) -> Unit)? = null
) {
    suspend fun dnsAccessible(
        dnsServer: String
    ) = try {
        withContext(Dispatchers.IO) {
            Runtime.getRuntime().exec("/system/bin/ping -c 1 $dnsServer").waitFor()
        } == 0
    } catch (e: Exception) {
        false
    }

    var isOnline by remember { mutableStateOf(false) }
    LaunchedEffect(Unit) {
        while (true) {
            isOnline = dnsServers.any { dnsAccessible(it) }
            onlineChanged?.invoke(isOnline)
            delay(delay)
        }
    }
    if (isOnline) successContent?.invoke()
    else errorContent?.invoke()
}

2022-11-10 18:46:36

其他回答

使用这个Kotlin扩展:

/**
 * Check whether network is available
 *
 * @param context
 * @return Whether device is connected to Network.
 */
fun Context.isNetworkAvailable(): Boolean {
    with(getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            //Device is running on Marshmallow or later Android OS.
            with(getNetworkCapabilities(activeNetwork)) {
                return hasTransport(NetworkCapabilities.TRANSPORT_WIFI) || hasTransport(
                    NetworkCapabilities.TRANSPORT_CELLULAR
                )
            }
        } else {
            activeNetworkInfo?.let {
                // connected to the internet
                @Suppress("DEPRECATION")
                return listOf(ConnectivityManager.TYPE_WIFI, ConnectivityManager.TYPE_MOBILE).contains(it.type)
            }
        }
    }
    return false
}

2019-12-25 14:14:42

public boolean isNetworkAvailable(Context context) {
    ConnectivityManager connectivityManager
            = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
    return activeNetworkInfo != null && activeNetworkInfo.isConnected();
}

以下是您需要的许可:

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

2016-08-17 13:56:42

你也可以用下面的代码上网查看:

 public class CheckInternetConnection {
        public Context context = null;

        public CheckInternetConnection(Context ctx) {
            this.context = ctx;
        }

        public boolean CheckInternet() {
            return isOnline();
        }
        public Boolean isOnline() 
        {
            try {
                if(isNetAvailable(context))
                    return true;
                else
                {
                    try {
                        URL url = new URL("http://www.google.com");
                        HttpURLConnection urlc = (HttpURLConnection) url
                                .openConnection();
                        urlc.setRequestProperty("User-Agent", "Test");
                        urlc.setRequestProperty("Connection", "close");
                        urlc.setConnectTimeout(3000); // This is time limit if the
                        // connection time limit
                        try {
                            urlc.connect();
                            Log.e("TAG", " urlc ----------" + urlc.getResponseCode());
                            if (urlc.getResponseCode() == 200) {
                                return true;
                            }
                        }catch (Exception e){
                            e.printStackTrace();
                        }
                    } catch (MalformedURLException e1) {
                        e1.printStackTrace();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }catch (Exception e){
                e.printStackTrace();
            }

            return false;        
        }

         public synchronized static boolean isNetAvailable(Context context){

             try{
             boolean isNetAvailable=false;
             if ( context != null )
             {
                 ConnectivityManager mgr = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
                 if ( mgr != null )
                 {
                     boolean mobileNetwork = false;
                     boolean wifiNetwork = false;
                     boolean wiMaxNetwork = false;

                     boolean mobileNetworkConnecetd = false;
                     boolean wifiNetworkConnecetd = false;
                     boolean wiMaxNetworkConnected = false;

                     NetworkInfo mobileInfo = mgr.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
                     NetworkInfo wifiInfo = mgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
                     NetworkInfo wiMaxInfo = mgr.getNetworkInfo(ConnectivityManager.TYPE_WIMAX);

                     if ( mobileInfo != null )
                         mobileNetwork = mobileInfo.isAvailable();                   

                     if ( wifiInfo != null )
                         wifiNetwork = wifiInfo.isAvailable();

                     if(wiMaxInfo != null)
                         wiMaxNetwork = wiMaxInfo.isAvailable();

                     if(wifiNetwork == true)
                         wifiNetworkConnecetd = wifiInfo.isConnectedOrConnecting();
                     if(mobileNetwork == true)
                         mobileNetworkConnecetd = mobileInfo.isConnectedOrConnecting();
                     if(wiMaxNetwork == true)
                         wiMaxNetworkConnected = wiMaxInfo.isConnectedOrConnecting();

                     isNetAvailable = ( mobileNetworkConnecetd || wifiNetworkConnecetd || wiMaxNetworkConnected );
                 }
             }
             return isNetAvailable;
             }catch(NullPointerException e)
             {
                 return false;
             }catch(Exception e)
             {
                 return false;
             }
         }


    }

2016-08-17 14:00:17

不要检查WIFI连接或移动数据连接，试着点击任何托管域。以便您可以检查WIFI/Mobile连接是否具有连接公共互联网的能力。

如果您的移动设备能够连接到所提供的公共域，则将返回以下内容。

boolean isReachable()
        {
            boolean connected = false;
            String instanceURL = "Your trusted domain name";
            Socket socket;
            try {
                socket = new Socket();
                SocketAddress socketAddress = new InetSocketAddress(instanceURL, 80);
                socket.connect(socketAddress, 5000);
                if (socket.isConnected()) {
                    connected = true;
                    socket.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                socket = null;
            }
            return connected;
        }

希望对大家有所帮助。

2017-02-21 11:54:21

我已经尝试了近5+不同的android方法，发现这是谷歌提供的最佳解决方案，特别是android:

  try {
  HttpURLConnection urlConnection = (HttpURLConnection)
  (new URL("http://clients3.google.com/generate_204")
  .openConnection());
  urlConnection.setRequestProperty("User-Agent", "Android");
  urlConnection.setRequestProperty("Connection", "close");
  urlConnection.setConnectTimeout(1500);
  urlConnection.connect();
  if (urlConnection.getResponseCode() == 204 &&
  urlConnection.getContentLength() == 0) {
  Log.d("Network Checker", "Successfully connected to internet");
  return true;
  }
  } catch (IOException e) {
  Log.e("Network Checker", "Error checking internet connection", e);
  }

它比任何其他可用的解决方案都更快、高效和准确。

2016-09-29 09:27:16

如何检查Android上的互联网接入?InetAddress从不超时

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