GWT - Communicating Data Structures

Data structures in GWT are typically classes (Java style). The declaration of the classes is shared between the client code and the server code. This eases the programmer's work, and insures that the data structures are consistent in both places.

When a list of records is needed, the communication is done with a Java ArrayList object, or something similar. The server builds the list, and the client iterates through the list and builds the user interface.