Google Ajax Framework Web Toolkit Released

What is Google Web Toolkit?
Google Web Toolkit (GWT) is a Java development framework that lets you escape the matrix of technologies that make writing AJAX applications so difficult and error prone. With GWT, you can develop and debug AJAX applications in the Java language using the Java development tools of your choice. When you deploy your application to production, the GWT compiler to translates your Java application to browser-compliant JavaScript and HTML.

Here's the GWT development cycle:

Use your favorite Java IDE to write and debug an application in the Java language, using as many (or as few) GWT libraries as you find useful.

Use GWT's Java-to-JavaScript compiler to distill your application into a set of JavaScript and HTML files that you can serve with any web server.

Confirm that your application works in each browser that you want to support, which usually takes no additional work

Why Translate Java Code to JavaScript?
Java technologies offer a productive development plaform, and with GWT, they can instantly become the basis of your AJAX development platform as well. Here are some of the benefits of developing with GWT:

You can use all of your favorite Java development tools (Eclipse, IntelliJ, JProfiler, JUnit) for AJAX development.

Static type checking in the Java language boosts productivity while reducing errors.

Common JavaScript errors (typos, type mismatches) are easily caught at compile time rather than by users at runtime.

Code prompting/completion is widely available.

Automated Java refactoring is pretty snazzy these days.

Java-based OO designs are easier to communicate and understand, thus making your AJAX code base more comprehensible with less documentation.

Google Web Toolkit Architecture
GWT has four major components: a Java-to-JavaScript compiler, a "hosted" web browser, and two Java class libraries:

• GWT Java-to-JavaScript Compiler
  
  
  The GWT Java-to-JavaScript compiler translates the Java programming language to the JavaScript programming language. You use the GWT compiler to run your GWT applications in web mode.
  
  
• GWT Hosted Web Browser
  
  
  The GWT Hosted Web Browser lets you run and execute your GWT applications in hosted mode, where you code runs as Java in the Java Virtual Machine without compiling to JavaScript. To accomplish this, the GWT browser embeds a special browser control (an Internet Explorer control on Windows or a Gecko/Mozilla control on Linux) with hooks into the JVM.
  
  
• JRE emulation library
  
  
  GWT contains JavaScript implementations of the most widely used classes in the Java standard class library, including most of the java.lang package classes and a subset of the java.util package classes. The rest of the Java standard library isn't supported natively within GWT. For example, packages like java.io don't apply to web applications since they access the network and local file system.
  
  
• GWT Web UI class library
  
  
  The GWT web UI class library is a set of custom interfaces and classes that let your create web browser "widgets," like buttons, text boxes, images, and text. This is the core user interface library used to create GWT applications. GWT ships with the complete source code for the library under an open source license.

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