Get local (LAN) IP address

[Kevin]

I tried looking through the help and forum last night, but unless I missed it, I didn't see any way to get the local (LAN) IP address assigned to the device.

Is there any way to do this? I would like my app to try scanning the local network for something specific, but in order to do that I need to know more about the network they are on.

I could assume 192.168.1.x, (where x is 1-255) but not all LANs are alike.

As a bonus... is there any way to ensure that the device is on a WiFi connection? I didn't seem to see anythinng specific to that either?

 

[Gary Miyakawa]

Do some reading in the ABWifi library... I think this will help you out...


Gary M

 

[ZJP]

It's possible

'Activity module
Sub Process_Globals
    Dim MyLan As ServerSocket  ' Lib Network
End Sub
'
Sub Activity_Create(FirstTime As Boolean)
    If FirstTime Then
        MyLan.Initialize(0, "")
    End If
    Log(MyLan.GetMyIP) ' my ip local or not
    ' 
    If MyLan.GetMyIP = "127.0.0.1" Then  '
        ToastMessageShow("You are not connected", True)
        'ExitApplication
        'Return
    End If
    '
End Sub
'

 

[Kevin]

Thanks. I will look into this tomorrow.

 

[Erel]

The above code is correct. It is better to only initialize MyLan when FirstTime is True.

 

[ZJP]

Indeed.
The post has been updated.

JP

 

[peacemaker]

What's wrong

'Activity module
Sub Process_Globals
   'These global variables will be declared once when the application starts.
   'These variables can be accessed from all modules.
   Dim Server1 As ServerSocket
End Sub

Sub Activity_Create(FirstTime As Boolean)
If FirstTime Then   
   Server1.Initialize(80, "Server1")   'for testing the internet connection
End If
....

gives error:

java.net.BindException: Permission denied
   at org.apache.harmony.luni.platform.OSNetworkSystem.socketBindImpl(Native Method)
   at org.apache.harmony.luni.platform.OSNetworkSystem.bind(OSNetworkSystem.java:107)
   at org.apache.harmony.luni.net.PlainSocketImpl.bind(PlainSocketImpl.java:184)
   at java.net.ServerSocket.<init>(ServerSocket.java:138)
   at java.net.ServerSocket.<init>(ServerSocket.java:89)
   at anywheresoftware.b4a.objects.SocketWrapper$ServerSocketWrapper.Initialize(SocketWrapper.java:161)
   at peacemaker.mobilecourier.status._activity_create(status.java:260)
   at java.lang.reflect.Method.invokeNative(Native Method)
   at java.lang.reflect.Method.invoke(Method.java:521)
   at anywheresoftware.b4a.BA.raiseEvent2(BA.java:105)
   at peacemaker.mobilecourier.status.afterFirstLayout(status.java:84)
   at peacemaker.mobilecourier.status.access$100(status.java:16)
   at peacemaker.mobilecourier.status$WaitForLayout.run(status.java:72)
   at android.os.Handler.handleCallback(Handler.java:587)
   at android.os.Handler.dispatchMessage(Handler.java:92)
   at android.os.Looper.loop(Looper.java:123)
   at android.app.ActivityThread.main(ActivityThread.java:4627)
   at java.lang.reflect.Method.invokeNative(Native Method)
   at java.lang.reflect.Method.invoke(Method.java:521)
   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
   at dalvik.system.NativeStart.main(Native Method)
java.net.BindException: Permission denied
** Activity (status) Resume **
** Service (gps) Create **
....

?

 

[Erel]

You are missing the Internet permission. I guess that you are using a custom manifest file. Open AndroidManifest-Example.xml to see the permissions.

 

[peacemaker]

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

exists. And i never used "do not overwrite manifest file". Debugger works OK via b4a Bridge.
Network lib is v.1.11.

But strange that GetMyIP works OK, but the debugger is paused on the line "Server1.Initialize(80, "Server1") 'for testing the internet connection".
Internet is really accesible at this moment in emulator , and on the testing real device.

 

[Erel]

You should use a port number larger than 1024. Lower ports are restricted by the system.

 

[peacemaker]

Whoooo, it has helped, thanks, Erel !
I guess, it's (or will be) documented for B4A also.

 

[aidymp]

I tried looking through the help and forum last night, but unless I missed it, I didn't see any way to get the local (LAN) IP address assigned to the device.

Is there any way to do this? I would like my app to try scanning the local network for something specific, but in order to do that I need to know more about the network they are on.

I could assume 192.168.1.x, (where x is 1-255) but not all LANs are alike.

As a bonus... is there any way to ensure that the device is on a WiFi connection? I didn't seem to see anythinng specific to that either?

Hi Kevin! Im wondering how you got on with this? I too would like to scan my network for something specific! im wondering how you got on, and if you have any tips!

Basically Im looking for a ftp server, I cant add something to the server to announce its presence, im using code that detects the devices IP, then searches the range for active IP's, then trying to connect to the ftp, but its not working for me!

Thanks in advance

Aidy