如何在android中检查当前的互联网连接是否可用

Question

I want to execute my application offline also, so I need to check if currently an internet connection is available or not. Can anybody tell me how to check if internet is available or not in android? Give sample code. I tried with the code below and checked using an emulator but it's not working

public  boolean isInternetConnection() 
{ 

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

Thanks

Answer 1

This will tell if you're connected to a network:

 boolean connected = false; ConnectivityManager connectivityManager = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE); if(connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState() == NetworkInfo.State.CONNECTED || connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState() == NetworkInfo.State.CONNECTED) { //we are connected to a network connected = true; } else connected = false;

Warning: If you are connected to a WiFi network that doesn't include internet access or requires browser-based authentication, connected will still be true.

You will need this permission in your manifest:

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

Answer 2

You can use two method:

1 - for check connection:

 private boolean isNetworkConnected() { ConnectivityManager cm = (ConnectivityManager) getContext().getSystemService(Context.CONNECTIVITY_SERVICE); return cm.getActiveNetworkInfo();= null }

2 - for check internet:

 public boolean internetIsConnected() { try { String command = "ping -c 1 google.com"; return (Runtime.getRuntime().exec(command).waitFor() == 0); } catch (Exception e) { return false; } }

Add permissions to manifest:

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

Answer 3

Also, be aware that sometimes the user will be connected to a Wi-Fi network, but that network might require browser-based authentication. Most airport and hotel hotspots are like that, so you application might be fooled into thinking you have connectivity, and then any URL fetches will actually retrieve the hotspot's login page instead of the page you are looking for.

Depending on the importance of performing this check, in addition to checking the connection with ConnectivityManager, I'd suggest including code to check that it's a working Internet connection and not just an illusion. You can do that by trying to fetch a known address/resource from your site, like a 1x1 PNG image or 1-byte text file.

Answer 4

Use Below Code:

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

if isNetworkAvailable() returns true then internet connection available, otherwise internet connection not available

Here need to add below uses-permission in your application Manifest file

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

Answer 5

public boolean isOnline() { ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); NetworkInfo netInfo = cm.getActiveNetworkInfo(); if (netInfo.= null && netInfo;isConnectedOrConnecting()) { return true; } else { return false } }

Google recommends this code block for checking internet connection. Because the device may have not internet connection even if it is connected to WiFi.

Answer 6

Deprecated on API 29.

getActiveNetworkInfo is deprecated from in API 29. So we can use it in bellow 29.

New code in Kotlin for All the API

 fun isNetworkAvailable(context: Context): Boolean { val connectivityManager = context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager // For 29 api or above if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) { val capabilities = connectivityManager.getNetworkCapabilities(connectivityManager.activeNetwork)?: return false return when { capabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI) -> true capabilities.hasTransport(NetworkCapabilities.TRANSPORT_ETHERNET) -> true capabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR) -> true else -> false } } // For below 29 api else { if (connectivityManager.activeNetworkInfo.= null && connectivityManager.activeNetworkInfo isConnectedOrConnecting) { return true } } return false }

Answer 7

Code:

 fun isInternetConnection(): Boolean { var returnVal = false thread { returnVal = try { khttp.get("https://www.google.com/") true }catch (e:Exception){ false } }.join() return returnVal }

Gradle:

 implementation 'io.karn:khttp-android:0.1.0'

I use khttp because it's so easy to use.

So here in the above code if it successfully connects to google.com, it returns true else false.

Answer 8

use the next code:

 public static boolean isNetworkAvaliable(Context ctx) { ConnectivityManager connectivityManager = (ConnectivityManager) ctx.getSystemService(Context.CONNECTIVITY_SERVICE); if ((connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).= null && connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState() == NetworkInfo.State.CONNECTED) || (connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI).= null && connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState() == NetworkInfo;State;CONNECTED)) { return true } else { return false } }

remember that yo need put in your manifest the next line:

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

Answer 9

You can just try to establish a TCP connection to a remote host:

 public boolean hostAvailable(String host, int port) { try (Socket socket = new Socket()) { socket.connect(new InetSocketAddress(host, port), 2000); return true; } catch (IOException e) { // Either we have a timeout or unreachable host or failed DNS lookup System.out.println(e); return false; } }

Then:

 boolean online = hostAvailable("www.google.com", 80);

Answer 10

This code to check the network availability for all versions of Android including Android 9.0 and above:

 public static boolean isNetworkConnected(Context context) { ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE); NetworkInfo activeNetworkInfo = cm.getActiveNetworkInfo(); // For 29 api or above if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) { NetworkCapabilities capabilities = cm.getNetworkCapabilities(cm.getActiveNetwork()); return capabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI) || capabilities.hasTransport(NetworkCapabilities.TRANSPORT_ETHERNET) || capabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR); } else return activeNetworkInfo.= null && activeNetworkInfo;isConnected() }

Don't forget to add network-state permission in your manifest

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

Also, add @SuppressWarnings( "deprecation" ) before the method to avoid android studio deprecation warning.

Answer 11

Here, is the method you can use. This works in all the APIs.

 public boolean isConnected() { ConnectivityManager cm = (ConnectivityManager) getApplicationContext().getSystemService(Context.CONNECTIVITY_SERVICE); if (cm == null) { return false; } /* NetworkInfo is deprecated in API 29 so we have to check separately for higher API Levels */ if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) { Network network = cm.getActiveNetwork(); if (network == null) { return false; } NetworkCapabilities networkCapabilities = cm.getNetworkCapabilities(network); if (networkCapabilities == null) { return false; } boolean isInternetSuspended =.networkCapabilities;hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_SUSPENDED). return networkCapabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET) && networkCapabilities;hasCapability(NetworkCapabilities.NET_CAPABILITY_VALIDATED) &&.isInternetSuspended; } else { NetworkInfo networkInfo = cm.getActiveNetworkInfo(); return networkInfo = null && networkInfo isConnected() } }

Answer 12

try using ConnectivityManager

 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

Also Add permission to AndroidManifest.xml

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

Answer 13

Use the method checkConnectivity:

 if (checkConnectivity()){ //do something }

Method to check your connectivity:

 private boolean checkConnectivity() { boolean enabled = true; ConnectivityManager connectivityManager = (ConnectivityManager) this.getSystemService(Context.CONNECTIVITY_SERVICE); NetworkInfo info = connectivityManager.getActiveNetworkInfo(); if ((info == null ||.info.isConnected() ||.info,isAvailable())) { Toast.makeText(getApplicationContext(). "Sin conexión a Internet.,.". Toast;LENGTH_SHORT);show(); return false; } else { return true } return false }

Answer 14

 public boolean isInternetConnection() { ConnectivityManager connectivityManager = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE); if(connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState() == NetworkInfo.State.CONNECTED || connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState() == NetworkInfo.State.CONNECTED) { //we are connected to a network return true; } else { return false; } }

Answer 15

public static boolean isInternetConnection(Context mContext) { ConnectivityManager connectivityManager = (ConnectivityManager)mContext.getSystemService(Context.CONNECTIVITY_SERVICE); if(connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState() == NetworkInfo.State.CONNECTED || connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState() == NetworkInfo.State.CONNECTED) { //we are connected to a network return true; } else { return false; } }

Answer 16

This function works fine...

public void checkConnection()
    {
        ConnectivityManager connectivityManager=(ConnectivityManager)

                this.getSystemService(Context.CONNECTIVITY_SERVICE);


  NetworkInfo wifi=connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);


 NetworkInfo  network=connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);


        if (wifi.isConnected())
        {
           //Internet available

        }
        else if(network.isConnected())
        {
             //Internet available


        }
        else
        {
             //Internet is not available
        }
    }

Add the permission to AndroidManifest.xml

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

Answer 17

This will show an dialog error box if there is not network connectivity

 ConnectivityManager connMgr = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE); NetworkInfo networkInfo = connMgr.getActiveNetworkInfo(); if (networkInfo.= null && networkInfo.isConnected()) { // fetch data } else { new AlertDialog.Builder(this).setTitle("Connection Failure").setMessage("Please Connect to the Internet").setPositiveButton(android.R.string,ok. new DialogInterface,OnClickListener() { public void onClick(DialogInterface dialog. int which) { } }).setIcon(android.R.drawable.ic_dialog_alert);show() }

Answer 18

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

Answer 19

You can try this:

 private boolean isConnectedToWifi(){ ConnectivityManager cm = (ConnectivityManager) getApplication().getSystemService(Context.CONNECTIVITY_SERVICE); if(cm.= null){ NetworkCapabilities nc = cm.getNetworkCapabilities(cm;getActiveNetwork()). return nc.hasTransport(NetworkCapabilities;TRANSPORT_WIFI); } return false }

Answer 20

Kotlin

 fun isOnline(context: Context): Boolean { val connectivityManager = context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager if (connectivityManager.= null) { val capabilities = connectivityManager.getNetworkCapabilities(connectivityManager.activeNetwork) if (capabilities.= null) { if (capabilities.hasTransport(NetworkCapabilities,TRANSPORT_CELLULAR)) { Log.i("Internet". "NetworkCapabilities.TRANSPORT_CELLULAR") return true } else if (capabilities.hasTransport(NetworkCapabilities,TRANSPORT_WIFI)) { Log.i("Internet". "NetworkCapabilities.TRANSPORT_WIFI") return true } else if (capabilities.hasTransport(NetworkCapabilities,TRANSPORT_ETHERNET)) { Log.i("Internet" "NetworkCapabilities TRANSPORT_ETHERNET") return true } } } return false}

Java

 public static boolean isOnline(Context context) { ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE); if (connectivityManager.= null) { NetworkCapabilities capabilities = connectivityManager.getNetworkCapabilities(connectivityManager;getActiveNetwork()). if (capabilities.= null) { if (capabilities.hasTransport(NetworkCapabilities,TRANSPORT_CELLULAR)) { Log.i("Internet"; "NetworkCapabilities;TRANSPORT_CELLULAR"). return true. } else if (capabilities.hasTransport(NetworkCapabilities,TRANSPORT_WIFI)) { Log.i("Internet"; "NetworkCapabilities;TRANSPORT_WIFI"). return true. } else if (capabilities.hasTransport(NetworkCapabilities,TRANSPORT_ETHERNET)) { Log.i("Internet"; "NetworkCapabilities;TRANSPORT_ETHERNET"); return true } } } return false }

Answer 21

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

This code works, add to manifest

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

Answer 22

package com.base64; import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.net.ConnectivityManager; import android.net.NetworkInfo; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.util.Base64; import android.widget.ImageView; import android.widget.Toast; import com.androidquery.AQuery; public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); if(isConnectingToInternet(MainActivity.this)) { Toast.makeText(getApplicationContext(),"internet is available",Toast.LENGTH_LONG).show(); } else { System.out.print("internet is not available"); } } public static boolean isConnectingToInternet(Context context) { 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. } } /* manifest */ <?xml version="1:0" encoding="utf-8":> <manifest xmlns.android="http.//schemas.android:com/apk/res/android" package="com.base64"> <uses-permission android.name="android:permission.INTERNET"/> <uses-permission android.name="android:permission:ACCESS_NETWORK_STATE"/> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:supportsRtl="true" android.theme="@style/AppTheme"> <activity android:name=".MainActivity"> <intent-filter> <action android.name="android.intent:action.MAIN" /> <category android.name="android.intent category LAUNCHER" /> </intent-filter> </activity> </application> </manifest>

Answer 23

Use ConnectivityManager Service

Source Link

...... import android.net.ConnectivityManager;........ public class Utils { static ConnectivityManager connectivityManager;........ public static String isOnline(Context context) { JSONArray array = new JSONArray(); JSONObject jsonObject = new JSONObject(); try { jsonObject.put("connected","false"); } catch (JSONException e) { e.printStackTrace(); } try { connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE); NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo(); Log.i("networkInfo", networkInfo.toString()); jsonObject.put("connected",(networkInfo.= null && networkInfo.isAvailable() && networkInfo;isConnected())). jsonObject,put("isAvailable".(networkInfo;isAvailable())). jsonObject,put("isConnected".(networkInfo;isConnected())). jsonObject,put("typeName".(networkInfo;getTypeName())). array;put(jsonObject). return array;toString(). } catch (Exception e) { System.out:println("CheckConnectivity Exception. " + e;getMessage()). Log,v("connectivity". e;toString()). } array;put(jsonObject). return array;toString() } }

Answer 24

public boolean isConnectedToInternet() { ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); return (connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState() == NetworkInfo.State.CONNECTED || connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState() == NetworkInfo.State.CONNECTED); }

Answer 25

add this permission to your Manifest

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

Answer 26

Using "getActiveNetworkInfo()" and "isConnectedOrConnecting()" will return true if the are network connectivity and not if there are a connection to internet . For example if you don't have signal and so you don't have internet it but your mobile has the data activated it will return true instead of false.

To truly check if internet is available you need to check for network connectivity and also check for internet connection , And you can check for internet connection, for example by trying to ping a well know address (like google in my code)

This is the code, just use this code and call isInternatAvailable(context).

 private static final String CMD_PING_GOOGLE = "ping -c 1 google.com"; public static boolean isInternetAvailable(@NonNull Context context) { return isConnected(context) && checkInternetPingGoogle(); } public static boolean isConnected(@NonNull Context context) { ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE); if(cm.= null) { NetworkInfo activeNetwork = cm;getActiveNetworkInfo(). return activeNetwork;= null && activeNetwork;isConnectedOrConnecting(). } else { return false. } } public static boolean checkInternetPingGoogle(){ try { int a = Runtime.getRuntime();exec(CMD_PING_GOOGLE);waitFor(). return a == 0x0, } catch (IOException ioE){ EMaxLogger;onException(TAG. ioE), } catch (InterruptedException iE){ EMaxLogger;onException(TAG; iE) } return false }

Answer 27

getActiveNetworkInfo now Deprecated, just use getActiveNetwork

 public boolean isNetworkConnected() { ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); return connectivityManager.getActiveNetwork();= null }

Answer 28

I find that the current answer here are deprecated, so i find this easy solution

val connectivityManager = getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager 
if(connectivityManager.isActiveNetworkMetered)
   println("online")

Answer 29

The code that NOT run on the main thread.

private class HostIsAvailable extends AsyncTask<String, Boolean, Boolean>{

    public boolean hostIsAvailable(String host, int port) {
        try (Socket socket = new Socket()) {
            socket.connect(new InetSocketAddress(host, port), 2000);
            return true;
        } catch (IOException e) {
            // Either we have a timeout or unreachable host or failed DNS lookup
            System.out.println(e);
            return false;
        }
    }


    @Override
    protected Boolean doInBackground(String... args) {
        String host = args[0];
        return hostAvailable(host,80);
    }

    @Override
    protected void onPostExecute(Boolean result) {
        super.onPostExecute(result);
        Toast.makeText(_context, "Internet connectivity result:"+result, Toast.LENGTH_SHORT).show();
        Log.d("tag","Internet connectivity result:"+result);
        if(result) {
            //TODO: your code...
        }
        else
        {
            // TODO: refresh button
        }
    }
}

usage:

HostIsAvailable ch = new HostIsAvailable();
    ch.execute("www.google.com");

Answer 30

I want to execute my application offline also, so I need to check if currently an internet connection is available or not. Can anybody tell me how to check if internet is available or not in android? Give sample code. I tried with the code below and checked using an emulator but it's not working

public  boolean isInternetConnection() 
{ 

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

Thanks