PropertyChangeSupport在GWT中的应用

Question

在我的gwt应用程序中，有人开发了一个使用java.beans.PropertyChangeSupport的模块。最近，我已经开始使用该模块并获得--在运行时导入java.beans无法解决错误。但应用程序运行良好。为什么我在gwt dev模式窗口中得到编译器错误？有什么想法吗？

00:17:33.079  [ERROR] Errors in 'file:/D:/workspace/App/src/main/java/com/abc/def/client/extract/pojos/ClientData.java'
00:17:33.079  [ERROR] Line 3: The import java.beans cannot be resolved
00:17:33.079  [ERROR] Line 4: The import java.beans cannot be resolved
00:17:33.079  [ERROR] Line 11: PropertyChangeSupport cannot be resolved to a type
00:17:33.079  [ERROR] Line 14: PropertyChangeSupport cannot be resolved to a type
00:17:33.079  [ERROR] Line 14: PropertyChangeSupport cannot be resolved to a type
00:17:33.079  [ERROR] Line 17: PropertyChangeListener cannot be resolved to a type
00:17:33.079  [ERROR] Line 18: PropertyChangeSupport cannot be resolved to a type
00:17:33.079  [ERROR] Line 21: PropertyChangeListener cannot be resolved to a type
00:17:33.079  [ERROR] Line 22: PropertyChangeSupport cannot be resolved to a type
00:17:33.079  [ERROR] Line 25: PropertyChangeListener cannot be resolved to a type
00:17:33.079  [ERROR] Line 26: PropertyChangeSupport cannot be resolved to a type
00:17:33.079  [ERROR] Line 30: PropertyChangeListener cannot be resolved to a type
00:17:33.079  [ERROR] Line 31: PropertyChangeSupport cannot be resolved to a type
00:17:33.079  [ERROR] Line 36: PropertyChangeListener cannot be resolved to a type
00:17:33.079  [ERROR] Line 36: PropertyChangeSupport cannot be resolved to a type

Answer 1

GWT只实现一个JRE类型的子集。DevMode工作的原因是它根据系统的JRE类型编译您的Java源代码，以获得更好的运行时性能。在运行生产模式编译时，它使用gwt-user.jar中的com/google/gwt/emul/java/...文件。

通用反射与死区代码剥离和多种单块优化形式不兼容，因此GWT编译器不实现运行时反射。GWT 发电机系统可以在编译时访问模块的整个类型系统，因此您可以实现足够的“静态”反射以满足您的需要。

如果您正在构建一个基于“状态袋”的系统，您可能需要查看AutoBeans框架，它通过访问者模式提供轻量级属性反射。