There are many benefits using OpenLayers for map functionalities compared with using map apis directly. here is a list of lessons I learned when I started out to use OpenLayers, they are basic important concepts therefor critical to the correct use of OpenLayers, another reason they are here is I found them confusing too.
It is just a self study note from http://code.google.com/webtoolkit/doc/latest/tutorial/Xsite.html Read the rest of this entry »
Part 1: JSON Ajax Server
It is just a simple HttpServlet which streams back a json string Read the rest of this entry »