I'm not the first guy who thought about JSON / XML mapping in GWT. Thus Piriti is not the only framework able to deal with JSON / XML data. This page gives an overview of the different techniques and frameworks to (de)serialize JSON and/or XML data. Please note that this list is not exhaustive. Furthermore the rating might be somewhat subjective ;-)

JavaScript Overlay Types

JavaScript overlay types were introduced in GWT 1.5 to to make it easy to integrate entire families of JavaScript objects into your GWT project.

Pros

• Quick and easy way to map simple JSON data

• No support of XML
• No custom paths, converters, format, ...

AutoBean

AutoBeans are a concept added in GWT 2.1.1. They provide automatically-generated implementations of bean-like interfaces and a low-level serialization mechanism for those interfaces.

Pros

• Officially supported by GWT
• Used by RequestFactory
• Can be used in both client and server code
• Lots of customizations possible

• No support of XML
• No custom paths, converters, format, ...
• Too much boilerplate IMHO

RestyGWT

RestyGWT is a GWT generator for REST services and JSON encoded data transfer objects. Using RestyGWT you can (de)serialize JSON data in a very similar manner to Piriti.

Pros

• Easy to use (convention over configuration)

• No support of XML
• No custom paths, converters, format, ...

RocketGWT

The Rocket GWT library/framework consists of a number of components that can assist developers get more out of GWT. One component deals with JSON (de)serialization

Cons

• Based on Javadoc comments
• Seems to be somewhat outdated

Acris

Acris is a framework for building applications, web sites and portals using Google Web Toolkit. It supports an annotation based JSON (de)serialization package.

Pros

• Custom deserializers
• Custom instantiators
• Map support

• No support of XML
• References must be defined as nested classes