如何找出GWT（客户端）中缺少哪些Java类？

此链接 GWT JRE Emulation Reference 显示您可以在客户端使用的类的列表。在那里有客户端库来添加缺少的小部件或功能到开箱即用的API。

I am trying to import a Java library into a GWT project.

Since the client-side of GWT does not have access to the whole Java API, some classes cannot be found.

Unfortunately, the compiler does not complain because the J2EE package is included into the project (for the server side code).

Now, how can I find out which Java classes, my library requires, are missing on client-side? Is there a list out there or something?

This link GWT JRE Emulation Reference shows the list of the classes you can use on the client side. There are out there client libraries to add missing widgets or features to the out-of-the-box API.