Google Web Toolkit

2010年8月21日 (六) 16:27的版本

Google Web Toolkit (GWT) is an open source Java software development framework that makes writing AJAX applications like Google Maps and Gmail easy for developers who don't speak browser quirks as a second language. Writing dynamic web applications today is a tedious and error-prone process; you spend 90% of your time working around subtle incompatibilities between web browsers and platforms, and JavaScript's lack of modularity makes sharing, testing, and reusing AJAX components difficult and fragile.

GWT lets you avoid many of these headaches while offering your users the same dynamic, standards-compliant experience. You write your front end in the Java programming language, and the GWT compiler converts your Java classes to browser-compliant JavaScript and HTML.

GWT big Picture http://en.weerasak.com/?p=48

概述

采取 Apache 2.0 许可协议

GWT除了支持将应用Java语言开发的应用转化为Ajax应用，同时提供了更多的高级特性，下面是这些特性的简单描述。

GWT编译器

GWT编译器是GWT的核心，负责完成将Java代码翻译很Ajax内容的工作。GWT编译器能够翻译Java语言的大部分特性。包括支持Java语言中的基本类型、违例处理等，支持java.lang包和java.util 包中的绝大部分类和接口，支持正则表达式和序列化。

跨平台支持

如果你使用GWT中提供的显示组件(比如Button)和组装组件(比如VerticalPanel)，GWT编译生成的Ajax应用能够支持大部分的浏览器和操作系统，比如Internet Explorer、Firefox等，也能够支持Linux、Windows等不同操作系统。这是因为GWT最大限度的将这些控件翻译成浏览器内置的类型。比如Button类编译后生成的是标准HTML:<input type="button">。 GWT建议使用CSS修饰页面元素的显示效果。GWT的类中很少提供访问页面元素样式属性的方法，我们可以直接在CSS文件中通过对应的样式名称来设置页面元素的默认显示效果。比如使用 .gwt-Button { font-size: 150%; } 使用Button元素的默认显示效果。

宿主模式(Hosted Mode)

宿主模式是指我们和没有转换为Ajax应用的GWT应用交互的状态。当我们开发和调试时，我们就一直处在宿主模式下。在这种情况下，Java虚拟机使用GWT内置的浏览器运行GWT应用编译后的class内容，因此能够提供"编码、测试、调试"过程的最佳速度。我们可以运行com.google.gwt.dev.GWTShell启动宿主模式。

Web模式(Web Mode)

Web模式是指已经成功转化为Ajax应用的状态，这种状态下，我们已经开始通过Web方式来访问Ajax应用了。在Web模式下运行时，不再需要GWT工具包或者JVM的支持。

命令行工具

GWT工具包中提供了几个非常适用的小工具来帮助我们更快的建立GWT应用开发环境:projectCreator、applicationCreator、junitCreator。

Features

Dynamic, reusable UI components
RPC

RPC Plumbing Diagram

An easy-to-use RPC(Remote Procedure Calls) mechanism for passing Java objects to and from a server over standard HTTP.

Browser history management
Real debugging
Browser compatible
JUnit integration
Internationalization
Interoperability and fine-grained control
Google API Library: Google Gears support

http://code.google.com/webtoolkit/overview.html

Guide

[allen@centos gwt-linux-1.4.61]$ ./applicationCreator -out Huihoo com.huihoo.client.App

Created directory Huihoo/src
Created directory Huihoo/src/com/huihoo
Created directory Huihoo/src/com/huihoo/client
Created directory Huihoo/src/com/huihoo/public
Created file Huihoo/src/com/huihoo/App.gwt.xml
Created file Huihoo/src/com/huihoo/public/App.html
Created file Huihoo/src/com/huihoo/client/App.java
Created file Huihoo/App-shell
Created file Huihoo/App-compile

[allen@centos gwt-linux-1.4.61]$ cd Huihoo/

[allen@centos Huihoo]$ ls
App-compile  App-shell  src

[allen@centos Huihoo]$ ./App-compile

Output will be written into ./www/com.huihoo.App
Copying all files found on public path
Compilation succeeded

Hello GWT

file:///Huihoo/www/com.huihoo.App/App.html

Powered by GWT

GoGrid is a cloud computing infrastructure service provider which enables you to deploy and scale load-balanced cloud server networks via a unique multi-server control panel. Justin Kitagawa, senior product manager and lead developer on GoGrid, shares how they used GWT to build GoGrid, what he likes and would like to see from GWT, and his tips and learnings from developing with GWT.

GWT Developers - GoGrid (2:50)
GWT Developer Soapbox (1:49)
GWT Developer Tips (0:44)

http://www.contactoffice.com/

Tools

GWT4NB

Games

GPokr - Texas Holdem Poker,
KDice - Online Strategy
XSketch - Word Sketch

Examples

@@ 第89行： / 第89行： @@
 *http://examples.roughian.com/
 *http://code.google.com/p/gwt-examples/
+[[Category:Google]]
+[[Category:Framework]]