A simple guest book on Google App Engine (Java)

终于算是有些时间,可以试试Google新推出的App Engine的Java语言支持。
Finally got some time to have a trial on Google App Engine – the Java Language.

我下载了Eclipse 3.4.1企业开发版并从更新站点安装了Google插件。在Google插件的帮助下,我在新工程里创建了一个简单的留言簿(GuestBook)模块,并根据文档和范例,写了一个留言(Comment)服务,下面跟用JDO(Java Data Objects)实现的DTO/DAO(Data Transfer/Access Objects)接起来。为了单元测试DAO,还依照GAE官方提供的方法写了JUnit test用的基类来创建App Engine的本地环境。
I’ve downloaded an Eclipse 3.4.1 EE and installed Google Plug-in for Eclipse via the update site. Using the Google Plug-in, I’ve created a GuestBook module, then a Comment service, and a JDO based DTO/DAO for Comment. In addition, I’ve tried out the unit test of a GAE project in local environment.

实际上做完这个例子兴奋劲就过去了,多少有些想法值得提一下,会放在下一篇博文里。
I’ve got some comments on this first trial, will update in another blog post later.

总之,以下是已经部署运行在Google云计算环境里边的例子应用:
Anyway, here is the running application hosted on Google’s cloud environment:

http://evis-lab.appspot.com/

源码也在Google Code上边,欢迎朋友们指正:
And the source code is always available here:

https://evis-lab.googlecode.com/svn/appengine/GuestBook/trunk

打算在GAE上尝试各种Java技术或框架的朋友们,不妨经常关注以下这个帖子:
For those are trying various Java techniques on GAE, a thread is strongly recommended:

Will It Play in App Engine (or this wiki page)