java.lang.ClassCastException: com.sun.proxy.$Proxy47 不能转换为
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时间：2020-11-02 23:02:27 来源:igfitidea点击:
java.lang.ClassCastException: com.sun.proxy.$Proxy47 cannot be cast to
提问by Joe Almore
I am running a test under Arquillian OSGi with this code:
我正在使用以下代码在 Arquillian OSGi 下运行测试：
An annotation:
注释：
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface Size {
int min() default 0;
int max() default 2147483647;
}
This class
这个班
public class FooEntity {
@Size(min = 0, max = 100)
public int number;
public int getNumber() {
return number;
}
public void setNumber(int number) {
this.number = number;
}
}
And a validation method somewhere else:
还有其他地方的验证方法：
@Override
public List<String> validateEntity(Object entity) throws IllegalAccessException {
List<String> list = new ArrayList<>();
for(Field field : entity.getClass().getDeclaredFields()) {
for (Annotation annotation : field.getDeclaredAnnotations()) {
if (annotation.annotationType().getName().equals(Size.class.getName())) {
Size size = (Size) annotation; // --> Throws 'ClassCastException' exception!!
int value = field.getInt(entity);
if (value < size.min() || value > size.max())
list.add("Error Message: Invalid size.");
}
}
}
return list;
}
When I debug this part of the code, I place this same line in the 'watch' window of the IDE and it shows the code is correct, I mean, it returns annotationas Sizetype, but during run-time the code just breaks. Does anybody knows why is this cast not working? And why is this annotation working under a Proxy class?
当我调试这部分代码时，我将同一行放在 IDE 的“观察”窗口中，它显示代码是正确的，我的意思是，它annotation作为Size类型返回，但在运行时代码会中断。有谁知道为什么这个演员不起作用？为什么这个注释在 Proxy 类下工作？
Here is the StackTrace of the exception:
这是异常的 StackTrace：
java.lang.ClassCastException: com.sun.proxy.$Proxy47 cannot be cast to persistence.ext.annotation.Size
at persistence.ext.internal.PersistenceImpl.validateEntity(PersistenceImpl.java:144)
at integration.PersistenceExtTest.ValidateSizeAnnotation(PersistenceExtTest.java:84)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.junit.runners.model.FrameworkMethod.runReflectiveCall(FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
at org.jboss.arquillian.junit.Arquillian.invoke(Arquillian.java:370)
at org.jboss.arquillian.container.test.impl.execution.LocalTestExecuter.execute(LocalTestExecuter.java:60)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:94)
at org.jboss.arquillian.core.impl.EventContextImpl.invokeObservers(EventContextImpl.java:99)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:81)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:145)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:116)
at org.jboss.arquillian.core.impl.EventImpl.fire(EventImpl.java:67)
at org.jboss.arquillian.container.test.impl.execution.ContainerTestExecuter.execute(ContainerTestExecuter.java:38)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:94)
at org.jboss.arquillian.core.impl.EventContextImpl.invokeObservers(EventContextImpl.java:99)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:81)
at org.jboss.arquillian.test.impl.TestContextHandler.createClassContext(TestContextHandler.java:92)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:94)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.test.impl.TestContextHandler.createTestContext(TestContextHandler.java:130)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:94)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.test.impl.TestContextHandler.createSuiteContext(TestContextHandler.java:73)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:94)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:145)
at org.jboss.arquillian.test.impl.EventTestRunnerAdaptor.test(EventTestRunnerAdaptor.java:136)
at org.jboss.arquillian.junit.Arquillian.evaluate(Arquillian.java:363)
at org.jboss.arquillian.junit.Arquillian.evaluate(Arquillian.java:245)
at org.jboss.arquillian.junit.Arquillian.multiExecute(Arquillian.java:422)
at org.jboss.arquillian.junit.Arquillian.access0(Arquillian.java:54)
at org.jboss.arquillian.junit.Arquillian.evaluate(Arquillian.java:259)
at org.jboss.arquillian.junit.Arquillian.invoke(Arquillian.java:315)
at org.jboss.arquillian.container.test.impl.execution.BeforeLifecycleEventExecuter.on(BeforeLifecycleEventExecuter.java:35)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:94)
at org.jboss.arquillian.core.impl.EventContextImpl.invokeObservers(EventContextImpl.java:99)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:81)
at org.jboss.arquillian.test.impl.TestContextHandler.createClassContext(TestContextHandler.java:92)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:94)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.test.impl.TestContextHandler.createTestContext(TestContextHandler.java:130)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:94)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.test.impl.TestContextHandler.createSuiteContext(TestContextHandler.java:73)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:94)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:145)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:116)
at org.jboss.arquillian.test.impl.EventTestRunnerAdaptor.fireCustomLifecycle(EventTestRunnerAdaptor.java:159)
at org.jboss.arquillian.junit.Arquillian.evaluate(Arquillian.java:311)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access##代码##0(ParentRunner.java:53)
at org.junit.runners.ParentRunner.evaluate(ParentRunner.java:229)
at org.jboss.arquillian.junit.Arquillian.evaluate(Arquillian.java:204)
at org.jboss.arquillian.junit.Arquillian.multiExecute(Arquillian.java:422)
at org.jboss.arquillian.junit.Arquillian.access0(Arquillian.java:54)
at org.jboss.arquillian.junit.Arquillian.evaluate(Arquillian.java:218)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at org.jboss.arquillian.junit.Arquillian.run(Arquillian.java:166)
at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
at org.junit.runner.JUnitCore.run(JUnitCore.java:138)
at org.jboss.arquillian.junit.container.JUnitTestRunner.execute(JUnitTestRunner.java:66)
at org.jboss.arquillian.osgi.JUnitBundleTestRunner.execute(JUnitBundleTestRunner.java:51)
at org.jboss.arquillian.protocol.jmx.JMXTestRunner.doRunTestMethod(JMXTestRunner.java:180)
at org.jboss.arquillian.protocol.jmx.JMXTestRunner.runTestMethodInternal(JMXTestRunner.java:162)
at org.jboss.arquillian.protocol.jmx.JMXTestRunner.runTestMethod(JMXTestRunner.java:120)
at org.jboss.arquillian.osgi.ArquillianBundleActivator.runTestMethod(ArquillianBundleActivator.java:111)
at org.jboss.arquillian.protocol.jmx.JMXTestRunner.runTestMethod(JMXTestRunner.java:137)
at org.jboss.arquillian.osgi.ArquillianBundleActivator.runTestMethod(ArquillianBundleActivator.java:124)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
at com.sun.jmx.mbeanserver.StandardMBeanIntrospector.invokeM2(StandardMBeanIntrospector.java:112)
at com.sun.jmx.mbeanserver.StandardMBeanIntrospector.invokeM2(StandardMBeanIntrospector.java:46)
at com.sun.jmx.mbeanserver.MBeanIntrospector.invokeM(MBeanIntrospector.java:237)
at com.sun.jmx.mbeanserver.PerInterface.invoke(PerInterface.java:138)
at com.sun.jmx.mbeanserver.MBeanSupport.invoke(MBeanSupport.java:252)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
at javax.management.MBeanServerInvocationHandler.invoke(MBeanServerInvocationHandler.java:298)
at com.sun.proxy.$Proxy27.runTestMethod(Unknown Source)
at org.jboss.arquillian.protocol.jmx.JMXMethodExecutor.invoke(JMXMethodExecutor.java:80)
at org.jboss.arquillian.container.test.impl.execution.RemoteTestExecuter.execute(RemoteTestExecuter.java:109)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:94)
at org.jboss.arquillian.core.impl.EventContextImpl.invokeObservers(EventContextImpl.java:99)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:81)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:145)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:116)
at org.jboss.arquillian.core.impl.EventImpl.fire(EventImpl.java:67)
at org.jboss.arquillian.container.test.impl.execution.ClientTestExecuter.execute(ClientTestExecuter.java:57)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:94)
at org.jboss.arquillian.core.impl.EventContextImpl.invokeObservers(EventContextImpl.java:99)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:81)
at org.jboss.arquillian.container.test.impl.client.ContainerEventController.createContext(ContainerEventController.java:142)
at org.jboss.arquillian.container.test.impl.client.ContainerEventController.createTestContext(ContainerEventController.java:129)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:94)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.test.impl.TestContextHandler.createClassContext(TestContextHandler.java:92)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:94)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.test.impl.TestContextHandler.createTestContext(TestContextHandler.java:130)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:94)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.test.impl.TestContextHandler.createSuiteContext(TestContextHandler.java:73)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:94)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:145)
at org.jboss.arquillian.test.impl.EventTestRunnerAdaptor.test(EventTestRunnerAdaptor.java:136)
at org.jboss.arquillian.junit.Arquillian.evaluate(Arquillian.java:363)
at org.jboss.arquillian.junit.Arquillian.evaluate(Arquillian.java:245)
at org.jboss.arquillian.junit.Arquillian.multiExecute(Arquillian.java:422)
at org.jboss.arquillian.junit.Arquillian.access0(Arquillian.java:54)
at org.jboss.arquillian.junit.Arquillian.evaluate(Arquillian.java:259)
at org.jboss.arquillian.junit.Arquillian.evaluate(Arquillian.java:321)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access##代码##0(ParentRunner.java:58)
at org.junit.runners.ParentRunner.evaluate(ParentRunner.java:268)
at org.jboss.arquillian.junit.Arquillian.evaluate(Arquillian.java:204)
at org.jboss.arquillian.junit.Arquillian.multiExecute(Arquillian.java:422)
at org.jboss.arquillian.junit.Arquillian.access0(Arquillian.java:54)
at org.jboss.arquillian.junit.Arquillian.evaluate(Arquillian.java:218)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.jboss.arquillian.junit.Arquillian.run(Arquillian.java:166)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:74)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:211)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:67)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)
回答by Stephen C
Why is this cast not working?
为什么这个演员不起作用？
and
和
You can see what it prints from the code above:
annotationType().getName()==Size.class.getName()=="persistence.ext.annotation.Size"
您可以从上面的代码中看到它打印的内容：
annotationType().getName()==Size.class.getName()=="persistence.ext.annotation.Size"
I suspect, that the real reason for your problems is that you have (somehow) managed to get copies of the Sizeinterface loaded; i.e. in different classloaders. The class names appear to be the same, but if you check the classloaders (getClass().getClassLoader()), I suspect that you will find they are different.
我怀疑，您的问题的真正原因是您（以某种方式）设法Size加载了界面的副本；即在不同的类加载器中。类名似乎相同，但是如果您检查类加载器 ( getClass().getClassLoader())，我怀疑您会发现它们是不同的。
