We developed a small client application for BlackBerry phones that connects to MiaMia servers. A lot of things can be said about BlackBerry adherence to standards, but I don't want to use cuss words here. The main problem is that these phones were initially devised to serve as "corporate walkie-talkies", and only recently their design was stretched to accommodate the needs of the general public. In a nutshell, this is a hardware equivalent of Lotus Notes - a combination of lack of respect for standards and a kungfu grip on the corporate customers.
As a result, once in a while developers encounter what can be described as a "chastity belt" - when it comes to communications with external world. Look for blackberry connection problems in Google or read this frustrated rant that sums it all. And if, as a BlackBerry user, you encountered problems with MSN Messenger, IRC, or anything else - same reason.
By default, when possible and a proxy-based connection (MDS, BES, BIS) exists, BlackBerry seems to re-route all requests there. It is not at all certain that your tiny app will be allowed to go further. Chances are, it will be stopped, and possibly hang. However, there are two possibilities that should work in most cases:
- direct TCP/IP via GPRS network
- wireless connection
To cut the long story short, the easiest way to provide maximum coverage is to create a tiny function that will be used like this:
protected String getDeviceSpecificUrlParameters()
{
try {
if (net.rim.device.api.system.WLANInfo.getWLANState() == net.rim.device.api.system.WLANInfo.WLAN_STATE_CONNECTED)
{
return ";deviceside=true;interface=wifi;ConnectionSetup=delayed;retrynocontext=true";
}
} catch (Exception e) {} // doesn't matter, just go elsewhere
return ";deviceside=true";
}
then call it whenever you make a connection, e.g.
...
Connector.open(url + getDeviceSpecificUrlParameters());
...
If your application is designed to work across different platforms (like ours), you can re-implement that getDeviceSpecificUrlParameters() for whatever platform you need.
A word of warning: if it's a brand new phone, and the access to GPRS is not configured, you may need to explain your users how to set up their APN parameters. The carrier-specific parameters can be found here, here, and here.
