I have update my mobile to Android Lollipop, before updating to Lollipop it works fine. Now I am facing problem with network interface.
if (isWifiConnected()) {
Log.d(TAG,"Wifi is connected");
mNetIf = Utils.getActiveNetworkInterface();
String name = mNetIf.getName();
Log.d(TAG, "network interface in constructor" + NetworkInterface.getByName(name));
//do some multicast Operations.
}
If the WiFi is connected I should do some multicast operation in WiFi.
iswifiConnected method
public boolean isWifiConnected(){
ConnectivityManager connManager = (ConnectivityManager)mContext.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo mWifi = connManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
if (mWifi.isConnected()) {
return true;
}
return false;
}
Utils.getActiveNetworkInterface
public static NetworkInterface getActiveNetworkInterface() {
Enumeration<NetworkInterface> interfaces = null;
try {
interfaces = NetworkInterface.getNetworkInterfaces();
} catch (SocketException e) {
return null;
}
while (interfaces.hasMoreElements()) {
NetworkInterface iface = interfaces.nextElement();
Enumeration<InetAddress> inetAddresses = iface.getInetAddresses();
/* Check if we have a non-local address. If so, this is the active
* interface.
*
* This isn't a perfect heuristic: I have devices which this will
* still detect the wrong interface on, but it will handle the
* common cases of wifi-only and Ethernet-only.
*/
while (inetAddresses.hasMoreElements()) {
InetAddress addr = inetAddresses.nextElement();
if (!(addr.isLoopbackAddress() || addr.isLinkLocalAddress())) {
return iface;
}
}
}
return null;
}
Log
Wifi is connected
network interface in constructor**[rmnet0][3]t** [/fe80::32e3:daf0:ba51:f971%rmnet0%3][/27.57.104.11]//3g network interface
I am wondering how the app got 3g interface. It should get wlan interface, it work in all other mobile. Is it a bug?
Permissions:
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
You are using the ConnectivityManger but, to use the WiFi network in Android, the best choice is to use the WifiManager: it has many features dedicated to Wifi. In particular, if you want to get a NetworkInterface object referencing the WiFi Interface, you can use the following method:
public static NetworkInterface getActiveWifiInterface(Context context) throws SocketException, UnknownHostException {
WifiManager wifiManager = (WifiManager)context.getSystemService(Context.WIFI_SERVICE);
//Return dynamic information about the current Wi-Fi connection, if any is active.
WifiInfo wifiInfo = wifiManager.getConnectionInfo();
if(wifiInfo == null) return null;
InetAddress address = intToInet(wifiInfo.getIpAddress());
return NetworkInterface.getByInetAddress(address);
}
public static byte byteOfInt(int value, int which) {
int shift = which * 8;
return (byte)(value >> shift);
}
public static InetAddress intToInet(int value) {
byte[] bytes = new byte[4];
for(int i = 0; i<4; i++) {
bytes[i] = byteOfInt(value, i);
}
try {
return InetAddress.getByAddress(bytes);
} catch (UnknownHostException e) {
// This only happens if the byte array has a bad length
return null;
}
}
I think the problem is that getInetAddresses() returns a list of interfaces, and getActiveNetworkInterface is only returning the first one no matter what.
And so the interface you are getting depends on the order of the list which getInetAddresses() returns.
That being said, one of the solutions could be: look at the up interface, using isUp().
http://developer.android.com/reference/java/net/NetworkInterface.html#isUp()
Android would turn off the cellular connection to save power when connected to wifi networks, so by looking at only the UP interface, you should able to pin point the WiFi interface.
Related
How can I get the ip address of my phone when it is connected under wifi?
I found a method here but it returns something like 24.182.239.255 even if I'm under wifi and I expect something like 192.168.1.10.
I'd like something like:
if (you are under wifi)
String ip4 = getWifiIP()
else
String ip4 = getIPAddress with the method linked before
Many thanks!
So something to consider is that Formatter.formatIpAddress(int) is being deprecated:
This method was deprecated in API level 12.
Use getHostAddress(), which supports both IPv4 and IPv6 addresses. This method does not support IPv6 addresses.
So using formatIpAddress(int) is likely not a good long term solution, although it will work.
Here is a potential solution if you are looking to absolutely on get the IP address for the WiFi interface:
protected String wifiIpAddress(Context context) {
WifiManager wifiManager = (WifiManager) context.getSystemService(WIFI_SERVICE);
int ipAddress = wifiManager.getConnectionInfo().getIpAddress();
// Convert little-endian to big-endianif needed
if (ByteOrder.nativeOrder().equals(ByteOrder.LITTLE_ENDIAN)) {
ipAddress = Integer.reverseBytes(ipAddress);
}
byte[] ipByteArray = BigInteger.valueOf(ipAddress).toByteArray();
String ipAddressString;
try {
ipAddressString = InetAddress.getByAddress(ipByteArray).getHostAddress();
} catch (UnknownHostException ex) {
Log.e("WIFIIP", "Unable to get host address.");
ipAddressString = null;
}
return ipAddressString;
}
As stated in previous responses, you need to set the following in your AndroidManifest.xml:
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
Note that this is only an example solution. You should take time to check for null values and so on to make sure that the UX is smooth.
The irony is that on one hand Google is deprecating formatIpAddress(int), but still has getIpAddress() still returns an integer value. The IP address being an int also rules it out for being IPv6 compliant.
Next is the fact that endianness may or may not be an issue. I have only tested three devices and they have all been little-endian. It seems like endianness can vary depending on the hardware, even though we are running in VMs this can still be an issue. So to be on the safe side I added an endian check in the code.
getByAddress(byte[]) appears to want the integer value to be big endian. From researching this it appears that network byte order is big-endian. Makes sense since an address like 192.168.12.22 is a big-endian number.
Check out HammerNet GitHub project. It implements the code above along with a bunch of sanity checks, ability to handle defaults for AVDs, unit tests, and other things. I had to implement this for an app of mine and decided to open source the library.
If you would like to get the private IP address of your device when connected to Wi-Fi, you can try this.
WifiManager wifiMgr = (WifiManager) getSystemService(WIFI_SERVICE);
WifiInfo wifiInfo = wifiMgr.getConnectionInfo();
int ip = wifiInfo.getIpAddress();
String ipAddress = Formatter.formatIpAddress(ip);
Be sure to add the permission
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
to your manifest.
This will get you the WiFi IPv4, IPv6 or both.
public static Enumeration<InetAddress> getWifiInetAddresses(final Context context) {
final WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
final WifiInfo wifiInfo = wifiManager.getConnectionInfo();
final String macAddress = wifiInfo.getMacAddress();
final String[] macParts = macAddress.split(":");
final byte[] macBytes = new byte[macParts.length];
for (int i = 0; i< macParts.length; i++) {
macBytes[i] = (byte)Integer.parseInt(macParts[i], 16);
}
try {
final Enumeration<NetworkInterface> e = NetworkInterface.getNetworkInterfaces();
while (e.hasMoreElements()) {
final NetworkInterface networkInterface = e.nextElement();
if (Arrays.equals(networkInterface.getHardwareAddress(), macBytes)) {
return networkInterface.getInetAddresses();
}
}
} catch (SocketException e) {
Log.wtf("WIFIIP", "Unable to NetworkInterface.getNetworkInterfaces()");
}
return null;
}
#SuppressWarnings("unchecked")
public static<T extends InetAddress> T getWifiInetAddress(final Context context, final Class<T> inetClass) {
final Enumeration<InetAddress> e = getWifiInetAddresses(context);
while (e.hasMoreElements()) {
final InetAddress inetAddress = e.nextElement();
if (inetAddress.getClass() == inetClass) {
return (T)inetAddress;
}
}
return null;
}
Usage:
final Inet4Address inet4Address = getWifiInetAddress(context, Inet4Address.class);
final Inet6Address inet6Address = getWifiInetAddress(context, Inet6Address.class);
And don't forget:
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
Found this nice answer, https://gist.github.com/stickupkid/1250733
WifiManager wifiManager = (WifiManager) getSystemService(WIFI_SERVICE);
WifiInfo wifiInfo = wifiManager.getConnectionInfo();
int ipAddress = wifiInfo.getIpAddress();
String ipString = String.format(“%d.%d.%d.%d”, (ip & 0xff), (ip >> 8 & 0xff), (ip >> 16 & 0xff), (ip >> 24 & 0xff));
Based on my crash logs, it appears not every device returns the WiFi mac address.
Here is a cleaner version of the most popular reply.
final WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
final ByteBuffer byteBuffer = ByteBuffer.allocate(4);
byteBuffer.order(ByteOrder.LITTLE_ENDIAN);
byteBuffer.putInt(wifiInfo.getIpAddress());
try {
final InetAddress inetAddress = InetAddress.getByAddress(null, byteBuffer.array());
} catch (UnknownHostException e) {
//TODO: Return null?
}
If adb is installed in the terminal then do:
Runtime.getRuntime.exec("adb", "shell", "getprop", "dhcp.wlan0.ipaddress");
Add Following Permission.
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
WifiManager initialize in onCreate.
WifiManager wifiMgr = (WifiManager) getContext().getSystemService(context.WIFI_SERVICE);
Use following function.
public void WI-FI_IP() {
WifiInfo wifiInfo = wifiMgr.getConnectionInfo();
int ip = wifiInfo.getIpAddress();
String ipAddress = Formatter.formatIpAddress(ip);
}
The following code is from AOSP Settings. It get the active link's ip, not matter wifi or mobile. It's the most common way.
http://androidxref.com/8.0.0_r4/xref/packages/apps/Settings/src/com/android/settings/deviceinfo/Status.java#251
/**
* Returns the default link's IP addresses, if any, taking into account IPv4 and IPv6 style
* addresses.
* #param context the application context
* #return the formatted and newline-separated IP addresses, or null if none.
*/
public static String getDefaultIpAddresses(ConnectivityManager cm) {
LinkProperties prop = cm.getActiveLinkProperties();
return formatIpAddresses(prop);
}
private static String formatIpAddresses(LinkProperties prop) {
if (prop == null) return null;
Iterator<InetAddress> iter = prop.getAllAddresses().iterator();
// If there are no entries, return null
if (!iter.hasNext()) return null;
// Concatenate all available addresses, comma separated
String addresses = "";
while (iter.hasNext()) {
addresses += iter.next().getHostAddress();
if (iter.hasNext()) addresses += "\n";
}
return addresses;
}
Formatter.formatIpAddress(int) is deprecated:
WifiManager wm = (WifiManager) getSystemService(WIFI_SERVICE);
String ipAddress = BigInteger.valueOf(wm.getDhcpInfo().netmask).toString();
I want to know how to detect state of WiFi tethering. I've seen an article: Android 2.3 wifi hotspot API But it doesn't work! It returns always WIFI_AP_STATE_DISABLED = 1. It doesn't depend on real state of WiFi tethering.
Using reflection:
WifiManager wifi = (WifiManager) getSystemService(Context.WIFI_SERVICE);
Method[] wmMethods = wifi.getClass().getDeclaredMethods();
for (Method method: wmMethods) {
if (method.getName().equals("isWifiApEnabled")) {
try {
boolean isWifiAPenabled = method.invoke(wifi);
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
}
As you can see here
In addition to the reflexion, to get the Wifi tethering status update, you can listen to this broadcast Action :
IntentFilter filter = new IntentFilter("android.net.wifi.WIFI_AP_STATE_CHANGED");
To get all tethering option update :
IntentFilter filter = new IntentFilter("android.net.conn.TETHER_STATE_CHANGED");
Those actions are hidden inside the Android source code
First, you need to get WifiManager:
Context context = ...
final WifiManager wifi = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
Then:
public static boolean isSharingWiFi(final WifiManager manager)
{
try
{
final Method method = manager.getClass().getDeclaredMethod("isWifiApEnabled");
method.setAccessible(true); //in the case of visibility change in future APIs
return (Boolean) method.invoke(manager);
}
catch (final Throwable ignored)
{
}
return false;
}
Also you need to request a permission in AndroidManifest.xml:
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
Here is the Xamarin C# version if anyone is looking:
static Method isWifiApEnabledMethod;
public static bool IsWifiApEnabled ()
{
var wifiManager = WifiManager.FromContext (Application.Context);
if (isWifiApEnabledMethod == null)
{
try
{
isWifiApEnabledMethod = wifiManager.Class.GetDeclaredMethod ("isWifiApEnabled");
isWifiApEnabledMethod.Accessible = true; //in the case of visibility change in future APIs
}
catch (NoSuchMethodException e)
{
Debug.WriteLine ("Can't get method by reflection" + e);
}
catch (System.Exception ex)
{
Debug.WriteLine ("Can't get method by reflection" + ex);
}
}
if (isWifiApEnabledMethod != null)
{
try
{
return (bool)isWifiApEnabledMethod.Invoke (wifiManager);
}
catch (System.Exception ex)
{
Debug.WriteLine ("Can't invoke by reflection" + ex);
}
}
return false;
}
(without using reflection since they say google is restricting it)
I'm writting this answer 10 years later. also I don't know if this can be considered a good aproach or not but I first get the Wlan network interface IPs
and if there is no address I assume that it tethering isn't enabled. if there is an address, I check using the connectivity manger whether WI-FI is connected to a network or not. if there is an IP for the Wlan network interface but it isn't connected to a network, I assume tethering is enabled.
you probably would need to add this line to your manifest file
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
code to get the ip of an inteface (this only gets the IPv4, you can modify it to get the IPv6 or both if you want)
// method used to retrieve Wlan ip addresses IPv4 of the device.
public static String IpAddresses() throws NoAddressFoundException, SocketException {
Enumeration<NetworkInterface> Nics = NetworkInterface.getNetworkInterfaces();
while (Nics.hasMoreElements()) {
NetworkInterface NIC = Nics.nextElement();
if (NIC.isUp() && !NIC.isLoopback() && NIC.getName().contains("wlan")) {
Enumeration<InetAddress> Addresses = NIC.getInetAddresses();
while (Addresses.hasMoreElements()) {
InetAddress WlanAddress = Addresses.nextElement();
if (WlanAddress instanceof Inet4Address)
return WlanAddress.getHostAddress();
}
}
}
throw new NoAddressFoundException("No suitable wifi address found");
}
then if there is an address i check if wifi is connected by this method:
//method to check if the device is connected to a Wi-Fi network; it doesn't matter if network has access to internet
public static boolean isWifiConnected(Context context) {
ConnectivityManager ConMan = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo WifiInfo = ConMan.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
return WifiInfo.isConnected();
}
NOTE: the "NoAddressFoundException" is a custom exception in my app if anyone is wondering. it won't exist in your case.
Reflection is a poor way to achieve this.
We can inspect the DhcpInfo to determine if the device is allocating addresses (mobile hotspot) or is being allocated by another DHCP server.
Here is a kotlin function that will determine if a device is a mobile hotspot, it has not been widely tested so YMMV.
fun isMobileHotspot(manager: WifiManager): Boolean {
val info = manager.dhcpInfo
return (
info.ipAddress == 0
&& info.netmask == 0
&& info.gateway == 0
&& info.serverAddress == 16885952) // 192.168.1.1
}
I have a wifi LAN setup which does not have internet access. Just various other local wifi devices connected to it. The DHCP is configured to not return a gateway or dns server. Only an IP and netmask.
When I connect my android to this wifi AP it connects fine, but all internet connectivity on the phone stops working.
I would expect that since the wifi has no gateway setting that android should realize the internet can't go through that connection and should instead be routed through the 3G connection which is at 5 bars.
I've tried setting a static IP on the android phone as well, but this did not help.
The main reason for this setup is so that the android device can transfer data on this remote network to an internet based server since it can connect to the local devices without issue. However the 3G side is broken once the wifi is setup.
Any thoughts on how to work around this issue?
After a bit of coding and testing I have merged Squonk and this solution. This is the class I have created:
package it.helian.exampleprj.network;
import java.net.InetAddress;
import java.net.UnknownHostException;
import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo.State;
import android.net.wifi.WifiManager;
import android.text.TextUtils;
import android.util.Log;
public class NetworkUtils {
private static final String TAG_LOG = "ExamplePrj";
Context context;
WifiManager wifiMan = null;
WifiManager.WifiLock wifiLock = null;
public NetworkUtils(Context context) {
super();
this.context = context;
}
/**
* Enable mobile connection for a specific address
* #param context a Context (application or activity)
* #param address the address to enable
* #return true for success, else false
*/
public boolean forceMobileConnectionForAddress(Context context, String address) {
ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
if (null == connectivityManager) {
Log.d(TAG_LOG, "ConnectivityManager is null, cannot try to force a mobile connection");
return false;
}
//check if mobile connection is available and connected
State state = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE_HIPRI).getState();
Log.d(TAG_LOG, "TYPE_MOBILE_HIPRI network state: " + state);
if (0 == state.compareTo(State.CONNECTED) || 0 == state.compareTo(State.CONNECTING)) {
return true;
}
//activate mobile connection in addition to other connection already activated
int resultInt = connectivityManager.startUsingNetworkFeature(ConnectivityManager.TYPE_MOBILE, "enableHIPRI");
Log.d(TAG_LOG, "startUsingNetworkFeature for enableHIPRI result: " + resultInt);
//-1 means errors
// 0 means already enabled
// 1 means enabled
// other values can be returned, because this method is vendor specific
if (-1 == resultInt) {
Log.e(TAG_LOG, "Wrong result of startUsingNetworkFeature, maybe problems");
return false;
}
if (0 == resultInt) {
Log.d(TAG_LOG, "No need to perform additional network settings");
return true;
}
//find the host name to route
String hostName = extractAddressFromUrl(address);
Log.d(TAG_LOG, "Source address: " + address);
Log.d(TAG_LOG, "Destination host address to route: " + hostName);
if (TextUtils.isEmpty(hostName)) hostName = address;
//create a route for the specified address
int hostAddress = lookupHost(hostName);
if (-1 == hostAddress) {
Log.e(TAG_LOG, "Wrong host address transformation, result was -1");
return false;
}
//wait some time needed to connection manager for waking up
try {
for (int counter=0; counter<30; counter++) {
State checkState = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE_HIPRI).getState();
if (0 == checkState.compareTo(State.CONNECTED))
break;
Thread.sleep(1000);
}
} catch (InterruptedException e) {
//nothing to do
}
boolean resultBool = connectivityManager.requestRouteToHost(ConnectivityManager.TYPE_MOBILE_HIPRI, hostAddress);
Log.d(TAG_LOG, "requestRouteToHost result: " + resultBool);
if (!resultBool)
Log.e(TAG_LOG, "Wrong requestRouteToHost result: expected true, but was false");
state = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE_HIPRI).getState();
Log.d(TAG_LOG, "TYPE_MOBILE_HIPRI network state after routing: " + state);
return resultBool;
}
/**
* This method extracts from address the hostname
* #param url eg. http://some.where.com:8080/sync
* #return some.where.com
*/
public String extractAddressFromUrl(String url) {
String urlToProcess = null;
//find protocol
int protocolEndIndex = url.indexOf("://");
if(protocolEndIndex>0) {
urlToProcess = url.substring(protocolEndIndex + 3);
} else {
urlToProcess = url;
}
// If we have port number in the address we strip everything
// after the port number
int pos = urlToProcess.indexOf(':');
if (pos >= 0) {
urlToProcess = urlToProcess.substring(0, pos);
}
// If we have resource location in the address then we strip
// everything after the '/'
pos = urlToProcess.indexOf('/');
if (pos >= 0) {
urlToProcess = urlToProcess.substring(0, pos);
}
// If we have ? in the address then we strip
// everything after the '?'
pos = urlToProcess.indexOf('?');
if (pos >= 0) {
urlToProcess = urlToProcess.substring(0, pos);
}
return urlToProcess;
}
/**
* Transform host name in int value used by {#link ConnectivityManager.requestRouteToHost}
* method
*
* #param hostname
* #return -1 if the host doesn't exists, elsewhere its translation
* to an integer
*/
private int lookupHost(String hostname) {
InetAddress inetAddress;
try {
inetAddress = InetAddress.getByName(hostname);
} catch (UnknownHostException e) {
return -1;
}
byte[] addrBytes;
int addr;
addrBytes = inetAddress.getAddress();
addr = ((addrBytes[3] & 0xff) << 24)
| ((addrBytes[2] & 0xff) << 16)
| ((addrBytes[1] & 0xff) << 8 )
| (addrBytes[0] & 0xff);
return addr;
}
#SuppressWarnings("unused")
private int lookupHost2(String hostname) {
InetAddress inetAddress;
try {
inetAddress = InetAddress.getByName(hostname);
} catch (UnknownHostException e) {
return -1;
}
byte[] addrBytes;
int addr;
addrBytes = inetAddress.getAddress();
addr = ((addrBytes[3] & 0xff) << 24)
| ((addrBytes[2] & 0xff) << 16)
| ((addrBytes[1] & 0xff) << 8 )
| (addrBytes[0] & 0xff);
return addr;
}
public Boolean disableWifi() {
wifiMan = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
if (wifiMan != null) {
wifiLock = wifiMan.createWifiLock(WifiManager.WIFI_MODE_SCAN_ONLY, "HelianRCAWifiLock");
}
return wifiMan.setWifiEnabled(false);
}
public Boolean enableWifi() {
Boolean success = false;
if (wifiLock != null && wifiLock.isHeld())
wifiLock.release();
if (wifiMan != null)
success = wifiMan.setWifiEnabled(true);
return success;
}
}
This is the usage:
USAGE CODE
boolean mobileRoutingEnabled = checkMobileInternetRouting();
if(!mobileRoutingEnabled) {
networkUtils.disableWifi();
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
networkUtils.forceMobileConnectionForAddress(context, RCA_URL);
if(!mobileRoutingEnabled) {
networkUtils.enableWifi();
}
// This second check is for testing purpose
checkMobileInternetRouting();
return callWebService(RCA_COMPLETE_URL, _plate);
where checkMobileInternetRouting is:
private boolean checkMobileInternetRouting() {
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
State state = cm.getNetworkInfo(ConnectivityManager.TYPE_MOBILE_HIPRI).getState();
return 0 == state.compareTo(State.CONNECTED) || 0 == state.compareTo(State.CONNECTING);
}
USAGE PROCEDURE
Check if the routing to the host is enabled
If yes go with the communication regardless the wifi is connected or not and execute only points 6 (the point 4 will only check that routing is already enable without executing any rilevant action). Otherwise temporary disables the wifi.
Thread sleep of about 3 seconds for letting the 3g connection comes back
Set the 3g routing to the given url
Enable back the wifi
Now the given url can be called even with a wifi connection without net acces
CONCLUSIONS
This is a bit hacky but works properly. The only problem is that this routing has got a timeout of few seconds (like 20-30) that forces you to execute the entire above procedure once more. Setting this timeout to a higher value would be very good.
Google added some useful methods in Android SDK 21 for this purpose.
You can create NetworkRequest:
NetworkRequest networkRequest = new NetworkRequest.Builder()
.addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
.build();
And then you can request such network using ConnectivityManager. For example, you want to be sure that all HTTP requests will be passed through the network with internet access. You can build your Retrofit API in this way:
ApiConfig apiConfig;
ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
connectivityManager.requestNetwork(networkRequest, new ConnectivityManager.NetworkCallback() {
#Override
public void onAvailable(Network network) {
apiConfig = new Retrofit.Builder()
.baseUrl("https://api.imatrix.io/")
.client(new OkHttpClient.Builder()
.socketFactory(network.getSocketFactory())
.build())
.build()
.create(ApiConfig.class);
}
#Override
public void onLost(Network network) {
apiConfig = null;
}
});
Please, mind the thread-safety when you're using such snippet of code.
In addition, I suggest check ConnectivityManager#bindProcessToNetwork and this blog.
ConnectivityManager.NetworkCallback is an empty class and it has several methods.
From code, when you detect there is no connectivity, you could switch off WiFi...
As for a setting, there is none (no good way to check if there really is connectivity universally and reliably). But some phones do just what you describe automatically, like for example my LG P-970.
(Note: Android disconnects from mobile networks when it connects to a WiFi, so there is no way to still be connected to a WiFi but route internet access through mobile, even though Linux can do it (with the ip route ... suite of tools))
I can't guarantee this will work as it's something I only experimented with some time ago. I had a similar need to use 3G (or other mobile network) when the wifi-connected network had no route to the outside world.
The following code should drop the wifi connection in order to allow the mobile network to come in to play. You'll need to do various tests along the way and re-establish the wifi connection again afterwards...
WifiManager wifiMan = null;
WifiManager.WifiLock wifiLock = null;
private Boolean disableWifi() {
wifiMan = (WifiManager) getSystemService(Context.WIFI_SERVICE);
if (wifiMan != null) {
wifiLock = wifiMan.createWifiLock(WifiManager.WIFI_MODE_SCAN_ONLY, "MyWifiLock");
}
return wifiMan.setWifiEnabled(false);
}
private Boolean enableWifi() {
Boolean success;
if (wifiLock != null)
wifiLock.release();
if (wifiMan != null)
success = wifiMan.setWifiEnabled(true);
return success;
}
you don't need to code anything. i found an app that do exactly this thing. you can configure to disconnect automatically from the wifi if there is no internet from this connection.
https://play.google.com/store/apps/details?id=com.nLabs.internetconnectivity&hl=en
I have a prototype Android app that is listening for multicast packets to 'discover' clients to communicate with. The socket set up is similar to this:
InetAddress group = InetAddress.getByName("228.1.2.3");
MulticastSocket s = new MulticastSocket(4000);
s.joinGroup(group);
This works very well when all the devices are connected via WiFi. I would like to support this with the phone acting as a portable hotspot. However, while all my devices appear to connect to the hotspot correctly I no longer receive multicast data. I'm wondering if there are restrictions that disallow this type of communication in hotspot mode, or if there are is any additional network configuration required to enable this? I've tried this on a couple different devices running Gingerbread and Froyo with no luck.
As this article show:
https://plus.google.com/+Chainfire/posts/9NMemrKYnCd
MulticastSocket::setNetworkInterface()
would be the answer
you can find the wlan0 eth by :
public static NetworkInterface getWlanEth() {
Enumeration<NetworkInterface> enumeration = null;
try {
enumeration = NetworkInterface.getNetworkInterfaces();
} catch (SocketException e) {
e.printStackTrace();
}
NetworkInterface wlan0 = null;
StringBuilder sb = new StringBuilder();
while (enumeration.hasMoreElements()) {
wlan0 = enumeration.nextElement();
sb.append(wlan0.getName() + " ");
if (wlan0.getName().equals("wlan0")) {
//there is probably a better way to find ethernet interface
Log.i(TAG, "wlan0 found");
return wlan0;
}
}
return null;
}
Have a try and lemme know if it works or not in Hotspot mode...
Do you have the manifest permission and are you creating a lock?
For permission please see: 'CHANGE_WIFI_MULTICAST_STATE' in http://developer.android.com/reference/android/Manifest.permission.html
Also, to create a multicast lock... please see:
http://developer.android.com/reference/android/net/wifi/WifiManager.MulticastLock.html
I've had the same problem and came up with a solution by the combination of #braden, #user707606 and the mainly the post by Chainfire in this Link.
Post in the link is nice but doesn't really offer any code samples but here it's. First you need to Acquire Multicast Lock, this is needed for some Android devices, didn't try in most of them but it was mentioned in some other posts, so I've included it in my code.
Permission is required, so first, add the permissions into your Manifest file.
<uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
Then the second step is to acquire multicast lock in your method.
/* Acquire MultiCast Lock */
WifiManager wifi = (WifiManager) mContext.getSystemService(Context.WIFI_SERVICE);
WifiManager.MulticastLock multicastLock = wifi.createMulticastLock("multicastLock");
multicastLock.setReferenceCounted(true);
multicastLock.acquire();
And then, find your Wifi Network Interface
/**
* Finds Network Interface of Wifi Ethernet.
*
* #return
*/
public static NetworkInterface findWifiNetworkInterface() {
Enumeration<NetworkInterface> enumeration = null;
try {
enumeration = NetworkInterface.getNetworkInterfaces();
} catch (SocketException e) {
e.printStackTrace();
}
NetworkInterface wlan0 = null;
while (enumeration.hasMoreElements()) {
wlan0 = enumeration.nextElement();
if (wlan0.getName().equals("wlan0")) {
return wlan0;
}
}
return null;
}
Later, create a Multicast socket with an available port and set your Wifi NetworkInterface.
MulticastSocket multicastSocket = new MulticastSocket();
/* Set NetworkInterface of MultiCast Socket */
NetworkInterface wifiNetworkInterface = findWifiNetworkInterface();
if (wifiNetworkInterface != null) multicastSocket.setNetworkInterface(wifiNetworkInterface);
Then the rest of your implementation remains the same. And once you are done with Multicast Lock, it's recommended to release it.
#Peter Jankuliak
This is a good idea. Here is a simpler way.
private fun findWifiNetworkInterface(): NetworkInterface? {
var enumeration: Enumeration<NetworkInterface?>? = null
try {
enumeration = NetworkInterface.getNetworkInterfaces()
} catch (e: SocketException) {
e.printStackTrace()
}
var wlan0: NetworkInterface? = null
if (enumeration != null) {
while (enumeration.hasMoreElements()) {
wlan0 = enumeration.nextElement()
if (wlan0 != null) {
val list = wlan0.interfaceAddresses.requireNoNulls()
for (interfaceAddress in list) {
if(interfaceAddress.broadcast!=null){
return wlan0
}
}
}
}
}
return null
}
My Android app can only function with WiFi connected to the Internet. Thus, I use the following code to check if the device is connected:
ConnectivityManager conMgr = (ConnectivityManager)getSystemService(Activity.CONNECTIVITY_SERVICE);
boolean wifi = conMgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI).isConnected();
However, very often when the application is launched and WiFi connected to the Internet, I get the notification that is only shown when wifi = false. Have I missed something, or the check is not that accurate?
My project also relies on Wifi (although I use a private network). The following is my code for setting up a Wifi connection on start up:
private void initWIFI (WifiManager wifiMgr, String SSID, String key)
{
WifiInfo curr;
if (null == (curr = wifiMgr.getConnectionInfo())) // Get current wifi state
{
joinNetwork (wifiMgr, SSID, key);
}
else switch (curr.getSupplicantState())
{
case DISCONNECTED:
case DORMANT:
case INACTIVE:
case SCANNING:
joinNetwork (wifiMgr, SSID, key);
break;
default:
if (!curr.getSSID().equals (SSID))
joinNetwork (wifiMgr, SSID, key);
}
while (wifiMgr.getConnectionInfo().getIpAddress() == 0)
{
try
{
Thread.sleep (1000);
}
catch (Exception e)
{ }
}
}
/**This method is used to join the proper WiFi network when necessary. Normally,
* the Android retains network configuration and it is not necessary to manually
* re-join the desired network on software startup. However, when it is determined
* that the Android is not currently attached to the proper network, this function
* is used to correct that situation. */
private void joinNetwork (WifiManager wifiMgr, String SSID, String key)
{
try
{
WifiConfiguration wc = new WifiConfiguration();
wc.allowedAuthAlgorithms.set (WifiConfiguration.AuthAlgorithm.OPEN);
wc.allowedAuthAlgorithms.set (WifiConfiguration.AuthAlgorithm.SHARED);
wc.allowedGroupCiphers.set (WifiConfiguration.GroupCipher.WEP40);
wc.allowedGroupCiphers.set (WifiConfiguration.GroupCipher.WEP104);
wc.allowedKeyManagement.set (WifiConfiguration.KeyMgmt.NONE);
wc.allowedPairwiseCiphers.set (WifiConfiguration.PairwiseCipher.TKIP);
wc.allowedPairwiseCiphers.set (WifiConfiguration.PairwiseCipher.CCMP);
wc.allowedProtocols.set (WifiConfiguration.Protocol.WPA);
wc.allowedProtocols.set (WifiConfiguration.Protocol.RSN);
wc.hiddenSSID = false;
wc.priority = 32;
wc.SSID = "\"" + SSID + "\"";
wc.status = WifiConfiguration.Status.ENABLED;
wc.wepKeys[0] = key;
wc.wepTxKeyIndex = 0;
int netID;
if (-1 == (netID = wifiMgr.addNetwork (wc)))
{
listener.lostConnection (true);
}
else
{
wifiMgr.enableNetwork (netID, true);
Thread.sleep (5000); // Delay to allow the DHCP process to work
}
}
catch (Exception e)
{
listener.lostConnection (true);
}
}
It should be pointed out that I always use the same wireless access point, and the code in joinNetwork() is specifically configured for it, so if your configuration needs to be more flexible, then your solution may be more complex. Sadly, I do not remember the web site where I found the starting point for this code, but it didn't take a ton of Googling to find it. Finally, I'm pretty sure your application needs to have the ACCESS_WIFI_STATE and CHANGE_WIFI_STATE permissions.
I use code like this:
public static String getCurrentSsid(Context context) {
final WifiInfo wifiInfo = getCurrentWifiInfo(context);
if (wifiInfo != null && !StringUtil.isBlank(wifiInfo.getSSID())) {
return wifiInfo.getSSID();
}
return null;
}
public static WifiInfo getCurrentWifiInfo(Context context) {
final ConnectivityManager connManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
final NetworkInfo networkInfo = connManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
if (networkInfo != null && networkInfo.isConnected()) {
final WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
return wifiManager.getConnectionInfo();
}
return null;
}
At the same time be aware of this two issues 19078 and 3641.