如何检查Android手机未连接到互联网？

Question

I'm developing an application in android which fetches data from the database. I have developed the code to find whether the WIFI or Mobile data is ON or OFF like this:

protected boolean isNetworkAvailable()
{
    boolean connection=true;
    ConnectivityManager connectivityManager=(ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo[] activeNetworkInfo=connectivityManager.getAllNetworkInfo();
    for(NetworkInfo ni:activeNetworkInfo)
    {
        if(ni.getTypeName().equalsIgnoreCase("WIFI"))
            if(ni.isConnected())    
                haveConnectedWifi=true;
        if(ni.getTypeName().equalsIgnoreCase("MOBILE"))
            if(ni.isConnected())
                haveConnectedMobile=true;

    }
    if(haveConnectedWifi==false && haveConnectedMobile==false)
    {

    connection=false;
    }
        return connection;

    }

Now suppose that my WIFI or Mobile Data network is ON but I'm not connected to internet at all(WIFI not connected to any access point).How can i show this in android?

Thanks,

Answer 1

you can simply use this:

public boolean isNetworkAvailable() {
    ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo networkInfo = cm.getActiveNetworkInfo();
    // if no network is available networkInfo will be null
    // otherwise check if we are connected
    if (networkInfo != null && networkInfo.isConnected()) {
        return true;
    }
    return false;
}

Answer 2

This class is pretty complete :

public class ConnexionDetector extends BroadcastReceiver {
    /**
     * ATTRIBUTES
     */
    private Context         _context;
    private boolean         _noConnectivity;
    private String          _reason;
    private boolean         _isFailover;
    private static boolean  _isConnected        = false;
    private static boolean  _isConnectivityGood = true;

    public ConnexionDetector(Context context) {

        this._context = context;
    }

public void registerReceivers() {

    _context.registerReceiver(this, new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION));
}

public boolean isConnectingToInternet() {

    ConnectivityManager connectivity = (ConnectivityManager) _context.getSystemService(Context.CONNECTIVITY_SERVICE);
    if (connectivity != null) {
        NetworkInfo[] info = connectivity.getAllNetworkInfo();
        if (info != null)
            for (int i = 0; i < info.length; i++)
                if (info[i].getState() == NetworkInfo.State.CONNECTED) {
                    return true;
                }
    }
    return false;
}

public static NetworkInfo getNetworkInfo(Context context) {

    ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    return cm.getActiveNetworkInfo();
}

public static boolean isConnected(Context context) {

    NetworkInfo info = getNetworkInfo(context);
    return (info != null && info.isConnected());
}

public static boolean isConnectedWifi(Context context) {

    NetworkInfo info = getNetworkInfo(context);
    return (info != null && info.isConnected() && info.getType() == ConnectivityManager.TYPE_WIFI);
}

public static boolean isConnectedMobile(Context context) {

    NetworkInfo info = getNetworkInfo(context);
    return (info != null && info.isConnected() && info.getType() == ConnectivityManager.TYPE_MOBILE);
}

public static boolean isConnectedFast(Context context) {

    NetworkInfo info = getNetworkInfo(context);
    return (info != null && info.isConnected() && isConnectionFast(info.getType(), info.getSubtype()));
}

private static boolean isConnectionFast(int type, int subType) {

    if (type == ConnectivityManager.TYPE_WIFI) {
        return true;
    }
    else if (type == ConnectivityManager.TYPE_MOBILE) {
        switch (subType) {
            case TelephonyManager.NETWORK_TYPE_1xRTT:
                return false; // ~ 50-100 kbps
            case TelephonyManager.NETWORK_TYPE_CDMA:
                return false; // ~ 14-64 kbps
            case TelephonyManager.NETWORK_TYPE_EDGE:
                return false; // ~ 50-100 kbps
            case TelephonyManager.NETWORK_TYPE_EVDO_0:
                return true; // ~ 400-1000 kbps
            case TelephonyManager.NETWORK_TYPE_EVDO_A:
                return true; // ~ 600-1400 kbps
            case TelephonyManager.NETWORK_TYPE_GPRS:
                return false; // ~ 100 kbps
            case TelephonyManager.NETWORK_TYPE_HSDPA:
                return true; // ~ 2-14 Mbps
            case TelephonyManager.NETWORK_TYPE_HSPA:
                return true; // ~ 700-1700 kbps
            case TelephonyManager.NETWORK_TYPE_HSUPA:
                return true; // ~ 1-23 Mbps
            case TelephonyManager.NETWORK_TYPE_UMTS:
                return true; // ~ 400-7000 kbps
            case TelephonyManager.NETWORK_TYPE_UNKNOWN:
            default:
                return false;
        }
    }
    else {
        return false;
    }
}

@Override
public void onReceive(Context context, Intent intent) {

    _noConnectivity = intent.getBooleanExtra(ConnectivityManager.EXTRA_NO_CONNECTIVITY, false);
    _reason = intent.getStringExtra(ConnectivityManager.EXTRA_REASON);
    _isFailover = intent.getBooleanExtra(ConnectivityManager.EXTRA_IS_FAILOVER, false);
    //
    if (_noConnectivity) {
        _isConnected = false;
    }
    else {
        if (isConnectedFast(_context)) {
            _isConnectivityGood = true;
        }
        else {
            _isConnectivityGood = false;
        }
        _isConnected = true;
    }
}
}

Answer 3

Try this,

ConnectivityManager connec = (ConnectivityManager) c.getSystemService(Context.CONNECTIVITY_SERVICE);
        try {
            android.net.NetworkInfo wifi = connec.getNetworkInfo(ConnectivityManager.TYPE_WIFI);

        android.net.NetworkInfo mobile = connec.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);

        if (wifi.isConnected()||mobile.isConnected())  
            return true;
        else if (wifi.isConnected() && mobile.isConnected())  
            return true;
        else  
            return false;

    } catch (NullPointerException e) {
        Log.d("ConStatus", "No Active Connection");
        return false;
    }

Answer 4

This code might help you.

ConnectivityManager cn= (ConnectivityManager) getActivity().getSystemService(Context.CONNECTIVITY_SERVICE);


    NetworkInfo networkInfo = cn.getNetworkInfo(ConnectivityManager.TYPE_WIFI); 
    testwifi=networkInfo.isConnected();
    if(!testwifi)
        tv1.setText("wifi is off");
    else
        tv1.setText("wifi is on");

Answer 5

Try this:

public static void isNetworkAvailable(Context context){
    HttpGet httpGet = new HttpGet("http://www.google.com");
    HttpParams httpParameters = new BasicHttpParams();
    // Set the timeout in milliseconds until a connection is established.
    // The default value is zero, that means the timeout is not used.
    int timeoutConnection = 3000;
    HttpConnectionParams.setConnectionTimeout(httpParameters, timeoutConnection);
    // Set the default socket timeout (SO_TIMEOUT)
    // in milliseconds which is the timeout for waiting for data.
    int timeoutSocket = 5000;
    HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);

    DefaultHttpClient httpClient = new DefaultHttpClient(httpParameters);
    try{
        Log.d(TAG, "Checking network connection...");
        httpClient.execute(httpGet);
        Log.d(TAG, "Connection OK");
        return;
    }
    catch(ClientProtocolException e){
        e.printStackTrace();
    }
    catch(IOException e){
        e.printStackTrace();
    }

    Log.d(TAG, "Connection unavailable");
}

Source: Check for Active internet connection Android

Answer 6

call the isConnectingToInternet function of this class to check the internet connection where u want to check internet connectivity .

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;

public class ConnectionDetector {

private Context _context;

public ConnectionDetector(Context context) {
    this._context = context;
}

/**
 * Checking for all possible internet providers
 * **/
public boolean isConnectingToInternet() {
    ConnectivityManager connectivity = (ConnectivityManager) _context
            .getSystemService(Context.CONNECTIVITY_SERVICE);
    if (connectivity != null) {
        NetworkInfo[] info = connectivity.getAllNetworkInfo();
        if (info != null)
            for (int i = 0; i < info.length; i++)
                if (info[i].getState() == NetworkInfo.State.CONNECTED) {
                    return true;
                }

    }
    return false;
}
}

Answer 7

To ensure that actual internet is available or not need to ping any global url eg www.google.com

This will work 100%

public static boolean isNetwokReachable() {
        final ConnectivityManager connMgr = (ConnectivityManager) mSmartAndroidActivity.getSystemService(Context.CONNECTIVITY_SERVICE);
        final NetworkInfo netInfo = connMgr.getActiveNetworkInfo();

        if (netInfo != null && netInfo.isConnected()) {
            try {
                URL url = new URL("http://www.google.com");
                HttpURLConnection urlc = (HttpURLConnection) url.openConnection();
                urlc.setRequestProperty("User-Agent", "Android Application");
                urlc.setRequestProperty("Connection", "close");
                urlc.setConnectTimeout(10 * 1000);
                urlc.connect();
                if (urlc.getResponseCode() == 200) {
                    return true;
                } else {
                    return false;
                }
            } catch (Throwable e) {
                return false;
            }
        } else {
            return false;
        }
    }

Answer 8

i was searching this question's answer also then i do this in my code and it works . don't know , it is good or not .if there is something wrong please tell me about that.

Step : 1 Make a BaseActivity class and extends AppCompatActivity class and write code in this for network check and show message to user if there is no network connection :

import android.content.Context
import android.net.ConnectivityManager
import android.net.Network
import android.net.NetworkRequest
import android.os.Bundle
import android.util.Log
import android.view.View
import android.view.ViewGroup
import androidx.appcompat.app.AppCompatActivity
import com.google.android.material.snackbar.Snackbar

open class BaseActivity : AppCompatActivity() {

    private var cManager: ConnectivityManager? = null
    private var mCallback: ConnectivityManager.NetworkCallback? = null
    private var request : NetworkRequest? = null
    private var view: View? = null
    private var mSnackBar: Snackbar? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        cManager = getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
        request = NetworkRequest.Builder().build()

        // get root view where we want to show message
        view = window.decorView.rootView

        mCallback = object : ConnectivityManager.NetworkCallback() {
            override fun onLost(network: Network) {
                super.onLost(network)

                mSnackBar = Snackbar.make(view!!, "No Network connection", Snackbar.LENGTH_LONG)
                mSnackBar!!.duration = Snackbar.LENGTH_INDEFINITE
                mSnackBar!!.show()
            }

            override fun onAvailable(network: Network) {
                super.onAvailable(network)
                if (mSnackBar != null){
                    mSnackBar!!.dismiss()
                }
            }
        }
        cManager!!.registerNetworkCallback(request!!, mCallback!!)
    }
    override fun onStop() {
        super.onStop()
        cManager!!.unregisterNetworkCallback(mCallback!!)    
    }
}

Step 2:

Now in MainActivity class , extends this BaseActivity class.

class MainActivity : BaseActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

    }
}

step 3 : Don't forget to add this in AndroidManifest File

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

now run and check your application. :)