Re: Switch Network Connections

[Jirka Klimes <jklimes redhat com>]

On Monday 08 of November 2010 08:13:35 Jos Collin-ERS,HCLTech wrote:
> Hello,
> 
> I have a wired and a wireless connections available in my computer. Both of
> them are configured in the NetworkManager. How can I programatically
> choose (or switch) to wired or wireless connection, using java?. After
> choosing a connection my computer should use that particular connection to
> access the Internet.
> 
> I have searched in the NetworkManager spec, but didn't find anything useful
> for doing this.
> http://projects.gnome.org/NetworkManager/developers/spec.html
> 
> By the way, what is ActivateConnection under
> org.freedesktop.NetworkManager? Will it do the job for me?
> 
> Please suggest.
> 
> Thanks,
> Jos Collin

NetworkManager provides a D-Bus interface to communicate with it. The API is 
described by the link you provide, which is for version 0.7. For NM 0.8 use
http://projects.gnome.org/NetworkManager/developers/spec-08.html.

The ActivateConnection() is the right method to call for activating a 
connection (connect to the Internet) by NM.

You can talk to D-Bus with a number of utilities and languages.
command-line tools: dbus-send, qdbus, ...
D-Dus GUI (debuggers): d-feet, qdbusviewer, ...
languages: python, C, Java, ...

Using dbus-send, the call would look like this:
dbus-send --system --print-reply --dest="org.freedesktop.NetworkManager" 
/org/freedesktop/NetworkManager 
"org.freedesktop.NetworkManager.ActivateConnection" 
string:"org.freedesktop.NetworkManagerUserS
ettings" objpath:"/org/freedesktop/NetworkManagerSettings/34" 
objpath:"/org/freedesktop/NetworkManager/Devices/1" 
objpath:"/org/freedesktop/NetworkManager/AccessPoint/4"

You can find examples in C and python in NM source tree:
http://cgit.freedesktop.org/NetworkManager/NetworkManager/tree/examples

See also this thread:
http://old.nabble.com/Documentation-td28023791.html

For Java, you need to use java d-bus binding:
http://dbus.freedesktop.org/doc/dbus-java/

Jirka