Google Web Toolkit

The Google Web Toolkit (GWT [ ɡʉ ˑ ˑ i t]) is a toolkit for developing Web applications. It was released on May 17, 2006 by Google as free software under the terms of version 2.0 of the Apache License. Its special feature is a Java -to- JavaScript compiler, so that almost the entire development of client and server based on Java can be realized. Furthermore, the GWT is equipped with an XML parser, internationalization support, an interface for remote procedure calls, integration of JUnit and a small widget package for designing the graphical user interface (GUI). These can be created similar to Swing.

What the GWT essentially differs from most other frameworks of this kind, is the fact that the client-side code can be created entirely in Java. This brings significant advantages in the development, because proven development environments can be used. Furthermore, an internal application server (Tomcat or Jetty ) contain that comes when you develop in Hosted mode ( ie, for example in the development phase on a standalone personal computer) to use.

Asynchronous Communication

Communication with a remote server is possible via remote procedure calls. The GWT offers two possibilities: On the one hand JSON can be used. For large queries, it is on the other hand makes more sense to use the provided by the GWT classes from the com.google.gwt.user.client.rpc package. The communication is here, although carried out with the proprietary protocol GWT -RPC, but at the same time it makes the serialization and deserialization of Java objects transparent. In this way, need data, supplied by the server, not only cumbersome transformed into objects. Further, the interface AsyncCallback two methods by which you can react specifically to the success and failure case of a request. For the second approach, the use of a servlet server on the remote side is necessary.

About the JavaScript Native Interface ( JSNI [ ɟisni ː ] ) can embed JavaScript directly in the Java code, so that specific extensions are possible, which can not be realized by the scope of Java libraries from the GWT.

GWT 2.0

The final version of the GWT 2.0 is available since 8 December 2009. There are, among others, the following main changes include:

GWT 2.5

The final version 2.5 is available since 25 October 2012. There are, among others, the following main changes include: