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
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" />
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.
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" />
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" />
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" />
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);
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 recommend this code block. Use this. Because device can be not connected to Internet even if it is connected to wifi. Wifi can be not connected to Internet
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;
}
}
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;
}
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>
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" />
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;
}
}
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();
}
}
if you want to check the internet connection and it changes such wifi disconnection or mobile data you can use this library.
来源：https://stackoverflow.com/questions/5474089/how-to-check-currently-internet-connection-is-available-or-not-in-android