How to monitor network status in android

Question

How to monitor network status in activity? I'am working with google chat application.

I want to execute these lines only if network status changed.

if(...){
    GTalkChatDetails.chat(getApplicationContext());
    GTalkChatDetails.adddMsgListener(getApplicationContext());
}

Answer 1

create a class to look for signal change,

private class SignalStrengthListener extends PhoneStateListener 
    {
        @Override
        public void onSignalStrengthsChanged(android.telephony.SignalStrength signalStrength) 
        {
            // get the signal strength (a value between 0 and 31)
            int strengthAmplitude = signalStrength.getGsmSignalStrength();
            // do something with it
            GTalkChatDetails.chat(getApplicationContext());
                    GTalkChatDetails.adddMsgListener(getApplicationContext());
            super.onSignalStrengthsChanged(signalStrength);
        }
    }