Question

我有一个GWT webapp，它使用了一个RequestFactory - 应用程序似乎启动得很好，但是一旦我尝试在浏览器中打开它，就会出现这种异常：

com.google.web.bindery.requestfactory.server.RequestFactoryServlet doPost
SEVERE: Unexpected error
java.lang.ClassCastException: class com.myapp.console.shared.MyAppRequestFactoryDeobfuscatorBuilder
    at java.lang.Class.asSubclass(Class.java:3126)
    at com.google.web.bindery.requestfactory.vm.impl.Deobfuscator$Builder.load(Deobfuscator.java:52)
    at com.google.web.bindery.requestfactory.server.ResolverServiceLayer.updateDeobfuscator(ResolverServiceLayer.java:43)
    at com.google.web.bindery.requestfactory.server.ResolverServiceLayer.resolveRequestFactory(ResolverServiceLayer.java:176)
    at com.google.web.bindery.requestfactory.server.ServiceLayerDecorator.resolveRequestFactory(ServiceLayerDecorator.java:172)
    at com.google.web.bindery.requestfactory.server.ServiceLayerDecorator.resolveRequestFactory(ServiceLayerDecorator.java:172)
    at com.google.web.bindery.requestfactory.server.ServiceLayerDecorator.resolveRequestFactory(ServiceLayerDecorator.java:172)
    at com.google.web.bindery.requestfactory.server.ServiceLayerDecorator.resolveRequestFactory(ServiceLayerDecorator.java:172)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.google.web.bindery.requestfactory.server.ServiceLayerCache.getOrCache(ServiceLayerCache.java:233)
    at com.google.web.bindery.requestfactory.server.ServiceLayerCache.resolveRequestFactory(ServiceLayerCache.java:198)
    at com.google.web.bindery.requestfactory.server.SimpleRequestProcessor.process(SimpleRequestProcessor.java:215)
    at com.google.web.bindery.requestfactory.server.SimpleRequestProcessor.process(SimpleRequestProcessor.java:135)
    at com.google.web.bindery.requestfactory.server.RequestFactoryServlet.doPost(RequestFactoryServlet.java:133)
    ....

MyAppRequestFactoryDeobfuscatorBuilder类是自动生成的（我的类是MyAppRequestFactory），因此它很难调试。几周前，当我上次使用此应用程序时，这种情况不常发生。导致此错误的原因是什么？如何解决？我不是GWT专家，所以我会很感激小词和可理解的解释！

Answer 1

这可能是一个类加载器问题，Deobfuscator.Builder是从MyAppRequestFactoryDeobfuscatorBuilder的不同（和兄弟或子，而不是父）类加载器加载的，因此Deobfuscator.Builder父类{{1}与尝试加载它的MyAppRequestFactoryDeobfuscatorBuilder类不同。

你在现在和现在之间做了什么改变吗？

（注意：GWT 2.6.0's DevMode has a classloader issue，所以如果您更新到GWT 2.6.0并且没有严格遵循预期的项目布局 - 您的Deobfuscator.Builder和/或编译后的类中缺少一些库在WEB-INF/lib - 然后你可以运行这样的问题）

GWT Deobfuscator Builder ClassCastException

1 个答案: