I need to build a GWT application that will be called by an external application with specific URL parameters.
For example:
http://www.somehost.com/com.app
You can use the Activities and Places to do that. When you create the Place for your page, you can set the orderId as a member. This member can be used afterwords when you create the Activity associated with the place (in ActivityMapper).
The only restriction is that you can't send the orderId as a normal parameter. You will have to use an url with this form :
127.0.0.1:60206/XUI.html?#TestPlace:orderId=1