java.lang.ClassCastException: com.sun.proxy.$Proxy47 cannot be cast to
Why is this cast not working?
and
You can see what it prints from the code above:
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 Size
interface 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.
Joe Almore
Updated on June 05, 2022Comments
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Joe Almore almost 2 years
I am running a test under Arquillian OSGi with this code:
An annotation:
@Target(ElementType.FIELD) @Retention(RetentionPolicy.RUNTIME) public @interface Size { int min() default 0; int max() default 2147483647; }
This class
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:
@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
annotation
asSize
type, 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?Here is the StackTrace of the exception:
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$1.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$8$1.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$8.evaluate(Arquillian.java:363) at org.jboss.arquillian.junit.Arquillian$4.evaluate(Arquillian.java:245) at org.jboss.arquillian.junit.Arquillian.multiExecute(Arquillian.java:422) at org.jboss.arquillian.junit.Arquillian.access$200(Arquillian.java:54) at org.jboss.arquillian.junit.Arquillian$5.evaluate(Arquillian.java:259) at org.jboss.arquillian.junit.Arquillian$7$1.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$7.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$3.run(ParentRunner.java:238) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229) at org.jboss.arquillian.junit.Arquillian$2.evaluate(Arquillian.java:204) at org.jboss.arquillian.junit.Arquillian.multiExecute(Arquillian.java:422) at org.jboss.arquillian.junit.Arquillian.access$200(Arquillian.java:54) at org.jboss.arquillian.junit.Arquillian$3.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$2.runTestMethod(ArquillianBundleActivator.java:111) at org.jboss.arquillian.protocol.jmx.JMXTestRunner.runTestMethod(JMXTestRunner.java:137) at org.jboss.arquillian.osgi.ArquillianBundleActivator$2.runTestMethod(ArquillianBundleActivator.java:124) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275) at com.sun.jmx.mbeanserver.StandardMBeanIntrospector.invokeM2(StandardMBeanIntrospector.java:112) at com.sun.jmx.mbeanserver.StandardMBeanIntrospector.invokeM2(StandardMBeanIntrospector.java:46) at com.sun.jmx.mbeanserver.MBeanIntrospector.invokeM(MBeanIntrospector.java:237) at com.sun.jmx.mbeanserver.PerInterface.invoke(PerInterface.java:138) at com.sun.jmx.mbeanserver.MBeanSupport.invoke(MBeanSupport.java:252) at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819) at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801) at javax.management.MBeanServerInvocationHandler.invoke(MBeanServerInvocationHandler.java:298) at com.sun.proxy.$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$8.evaluate(Arquillian.java:363) at org.jboss.arquillian.junit.Arquillian$4.evaluate(Arquillian.java:245) at org.jboss.arquillian.junit.Arquillian.multiExecute(Arquillian.java:422) at org.jboss.arquillian.junit.Arquillian.access$200(Arquillian.java:54) at org.jboss.arquillian.junit.Arquillian$5.evaluate(Arquillian.java:259) at org.jboss.arquillian.junit.Arquillian$7.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$3.run(ParentRunner.java:290) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268) at org.jboss.arquillian.junit.Arquillian$2.evaluate(Arquillian.java:204) at org.jboss.arquillian.junit.Arquillian.multiExecute(Arquillian.java:422) at org.jboss.arquillian.junit.Arquillian.access$200(Arquillian.java:54) at org.jboss.arquillian.junit.Arquillian$3.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)
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Joe Almore over 8 yearsYes, they (the
field
and theannotation
variables) were in differentClassLoader
and this was happening because I was not importing thepersistence.ext.annotation
package into the Bundle, hence making the JVM to use a differentClassLoader
for the annotation. So, I just included thepersistence.ext.annotation
package into the Bundle manifest file and now they are both under the sameClassLoader
and it works.