Part of the development-time magic on Google Web Toolkit is the hosted mode browser. During development, we interact with our application in the hosted mode browser, which runs our Java byte-code on the back-end to render our user interface in an embedded browser.
Google Web Toolkit provides an optimized RPC mechanism for Java, which means we don't have to worry about the complexity of low-level HTTP interactions. Alternatively, we can also use easily JSON to communicate with the server.
Advantages of Google Web Toolkit
The learning curve is very slow for a Java developer;
Debugging it's as easy as debugging any pure Java applications
Developing Google Web Toolkit is quick thanks to error checking and syntax highlighting
Easy to manage client history that means that Google Web Toolkit provides back button support
We can use both JUnit and Mockito for unit testing. Google Web Toolkit makes very easy to apply TDD (Test-driven development) or BDD (Behavior-driven development) patterns.
Google Web Toolkit provides cross-browser support that means that our application will work similarly on the most recent versions of IE, Firefox, Chrome and Safari.
The UI Binder framework is an excellent tool to build our applications as HTML pages with Google Web Toolkit widgets sprinkled throughout them
Exchange Java object over HTTP between our client and server, it is straightforward using the Google Web Toolkit RPC framework
Disadvantages of Google Web Toolkit
Main Google recent projects are not longer developed with Google Web Toolkit
Used to have a good community behind but it is decreasing quickly
There is too much boilerplate code. Creating a simple table in Google Web Toolkit could take you more than a hundred lines.
Google Web Toolkit is only useful for Java developers, if we are coming from a different background I don't think Google Web Toolkit will be helpful for us
UI test are too slow. Although, if you apply correctly the Model-View-Presenter design pattern, you could minimize the use of GWTTestCase, and write fast JRE tests
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