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:
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: