Google Web Toolkit

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Google Web Toolkit (GWT) is an open source software development framework that allows web developers to create Ajax applications using the Java programming language. It is licensed under the Apache License version 2.0.[1]

GWT emphasizes reusable, efficient solutions to recurring Ajax challenges, namely asynchronous remote procedure calls, history management, bookmarking, and cross-browser portability.

History

GWT version 1.0 RC 1 (build 1.0.20) was released on May 16, 2006.[2] Google announced GWT at the JavaOne conference, 2006.[3]

Release history:

Development

Using GWT, the developers can rapidly develop and debug AJAX applications in the Java language using the Java development tools of their choice. When the application is deployed, the GWT compiler translates the Java application to browser-compliant JavaScript and HTML.

GWT applications can be run in two modes:

  • Hosted mode: The application is run as Java bytecode within the Java Virtual Machine (JVM). This mode is typically used for development.
  • Web mode: The application is run as pure JavaScript and HTML, compiled from the Java source. This mode is typically used for deployment.

A command-line utility shipped with GWT, applicationCreator, automatically generates all the files needed to start a GWT project. It can also generate Eclipse project files. Several open-source plugins are available for making GWT development easier with IDEs. E.g., GWT4NB for NetBeans, Cypal Studio for GWT for Eclipse, gwtDeveloper for JDeveloper etc.

Components

The major GWT components include:

GWT Java-to-JavaScript Compiler
Translates the Java programming language to the JavaScript programming language.
GWT Hosted Web Browser
Allows the developers to run and execute GWT applications in hosted mode (the app runs as Java in the JVM without compiling to JavaScript).
JRE emulation library
JavaScript implementations of the commonly used classes in the Java standard class library (such as most of the java.lang package classes and a subset of the java.util package classes).
GWT Web UI class library
A set of custom interfaces and classes for creating widgets.

Features

  • Dynamic and reusable UI components: programmers can use pre-designed classes to implement otherwise time-consuming dynamic behaviors, such as drag-and-drop or sophisticated visual tree structures.[4]
  • Simple RPC mechanism
  • Browser history management
  • Support for full-featured Java debugging.[3]
  • GWT handles all cross-browser issues for the developer.[3]
  • JUnit integration
  • Easy internationalization
  • The developers can mix handwritten JavaScript in the Java source code using the JavaScript Native Interface (JSNI).
  • Support for using Google APIs in GWT applications (initially, support for Google Gears)
  • Open-source
  • The developers can design and develop their application in a pure object-oriented fashion, since they're using Java (instead of JavaScript).[4] Common JavaScript errors (such as typos and type mismatches are caught at compile time.
  • JavaScript that the GWT compiler generates is quite obfuscated or very difficult to read, which provide the application with some security and protection of proprietary material.[4]
  • A number of libraries are available for GWT, by Google and third parties. These extend GWTs features.[4]

Available widgets

As of version 1.4 (August 2007), GWT offers several widgets:[5]

  • HTML primitives (Button, Radio Button, Checkbox, TextBox, PasswordTextBox, TextArea, Hyperlink, ListBox, Table etc.)
  • PushButton, ToggleButton
  • MenuBar
  • Tree
  • TabBar
  • DialogBox
  • Panels (PopupPanel, StackPanel, HorizontalPanel, VerticalPanel, FlowPanel, VerticalSplitPanel, HorizontalSplitPanel, DockPanel, TabPanel, DisclosurePanel)
  • RichTextArea
  • SuggestBox (auto-complete)

Many common widgets not found in the GWT have been implemented in third-party libraries, such as GWTiger, GWT Widget Library, GWT Component Library, Rocket GWT etc.

References

  1. Google Web Toolkit License Information (February 23, 2007). Retrieved on 2007-09-25.
  2. Google Web Toolkit Release Archive. Retrieved on 2007-09-25.
  3. 3.0 3.1 3.2 Olson, Steven Douglas (2007). Ajax on Java. O'Reilly, 183. ISBN 978-0596101879. 
  4. 4.0 4.1 4.2 4.3 Perry, Bruce W (2007). Google Web Toolkit for Ajax. O'Reilly, 1-5. ISBN 978-0596510220. 
  5. Widgets Gallery. Retrieved on 2007-09-25.

Bibliography

  • Dewsbury, Ryan (2007). Google Web Toolkit Applications. Prentice Hall. ISBN 978-0321501967. 
  • Chaganti, Prabhakar (2007). Google Web Toolkit: GWT Java Ajax Programming. Packt Publishing. ISBN 978-1847191007. 
  • Geary, David (2007). Google Web Toolkit Solutions: More Cool & Useful Stuff. Prentice Hall. ISBN 978-0132344814. 
  • Hanson, Robert; Adam Tacy (2007). GWT in Action: Easy Ajax with the Google Web Toolkit. Manning. ISBN 978-1933988238. 
  • Cooper, Robert; Charlie Collins (2008). GWT in Practice. Manning. ISBN 978-1933988290. 

External links