Improper noargs constructor assumption leads to NullPointerException -------------------------------------------------------------------- Key: WFLY-3527 URL: https://issues.jboss.org/browse/WFLY-3527 Project: WildFly Issue Type: Bug Affects Versions: 8.0.0.Final Reporter: Randahl Fink Isaksen Assignee: Bartosz Baranowski Priority: Critical As shown in the stack trace below, I have received a NullPointerException from Wildfly. Looking at the Wildfly code, it seems to me that the class org.jboss.marshalling.reflect.SerializableClass improperly requires serializable classes to have a noargs constructor. The NullPointerException occurs in line 514: {code} 514: return constructor.newInstance(args); {code} so the reason for the NullPointerException is that the parameter constructor is null. Now, if you look at line 488, you see that the constructor parameter stems from the method invokation {code} 488: return invokeConstructorNoException(nonInitConstructor); {code} so the question is: When is nonInitConstructor defined, and why is it null? The answer can be found in line 160 {code} 160: nonInitConstructor = lookupNonInitConstructor(subject); {code} and that method starts in line 550 {code} 550 private static <T> Constructor<T> More ...lookupNonInitConstructor(final … 555 topConstructor = current.getDeclaredConstructor(); 556 } catch (NoSuchMethodException e) { 557 return null; 558 } … 563 } {code} As you can see here, the method getDeclaredConstructor is invoked with no args, so Wildfly expects to find a noargs constructor. If non such constructor exists the NoSuchMethodException is thrown, caught, and null is returned. All in all I conclude, that creating a perfectly valid, serializable class with no noargs constructor makes Wildfly crash, and I believe this is a serious bug. CLASS WHICH MAKES WILDFLY FAIL {code} public enum Validity { VALID(true), QUESTIONABLE(true), INVALID(false); private boolean valid; private Validity(boolean valid) { this.valid = valid; } public boolean isValid() { return valid; } } {code} Note: Any enum is also Serializable STACK TRACE {noformat} java.lang.reflect.InvocationTargetException at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:483) at com.intuism.ui.validation.validator.ValidationTask.call(ValidationTask.java:49) at com.intuism.ui.validation.validator.ValidationTask.call(ValidationTask.java:23) at javafx.concurrent.Task$TaskCallable.call(Task.java:1426) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:744) Caused by: java.lang.NullPointerException at org.jboss.marshalling.reflect.SerializableClass.invokeConstructorNoException(SerializableClass.java:514) at org.jboss.marshalling.reflect.SerializableClass.callNonInitConstructor(SerializableClass.java:488) at org.jboss.marshalling.river.RiverUnmarshaller.doReadNewObject(RiverUnmarshaller.java:1270) at org.jboss.marshalling.river.RiverUnmarshaller.doReadObject(RiverUnmarshaller.java:276) at org.jboss.marshalling.river.RiverUnmarshaller.doReadObject(RiverUnmarshaller.java:213) at org.jboss.marshalling.river.RiverUnmarshaller.readFields(RiverUnmarshaller.java:1715) at org.jboss.marshalling.river.RiverUnmarshaller.doInitSerializable(RiverUnmarshaller.java:1631) at org.jboss.marshalling.river.RiverUnmarshaller.doReadNewObject(RiverUnmarshaller.java:1273) at org.jboss.marshalling.river.RiverUnmarshaller.doReadObject(RiverUnmarshaller.java:276) at org.jboss.marshalling.river.RiverUnmarshaller.doReadObject(RiverUnmarshaller.java:213) at org.jboss.marshalling.AbstractObjectInput.readObject(AbstractObjectInput.java:45) at org.jboss.ejb.client.remoting.MethodInvocationResponseHandler$MethodInvocationResultProducer.getResult(MethodInvocationResponseHandler.java:103) at org.jboss.ejb.client.EJBClientInvocationContext.getResult(EJBClientInvocationContext.java:272) at org.jboss.ejb.client.EJBObjectInterceptor.handleInvocationResult(EJBObjectInterceptor.java:64) at org.jboss.ejb.client.EJBClientInvocationContext.getResult(EJBClientInvocationContext.java:274) at org.jboss.ejb.client.EJBHomeInterceptor.handleInvocationResult(EJBHomeInterceptor.java:88) at org.jboss.ejb.client.EJBClientInvocationContext.getResult(EJBClientInvocationContext.java:274) at org.jboss.ejb.client.TransactionInterceptor.handleInvocationResult(TransactionInterceptor.java:46) at org.jboss.ejb.client.EJBClientInvocationContext.getResult(EJBClientInvocationContext.java:274) at org.jboss.ejb.client.ReceiverInterceptor.handleInvocationResult(ReceiverInterceptor.java:129) at org.jboss.ejb.client.EJBClientInvocationContext.getResult(EJBClientInvocationContext.java:262) at org.jboss.ejb.client.EJBClientInvocationContext.awaitResponse(EJBClientInvocationContext.java:437) at org.jboss.ejb.client.EJBInvocationHandler.doInvoke(EJBInvocationHandler.java:202) at org.jboss.ejb.client.EJBInvocationHandler.doInvoke(EJBInvocationHandler.java:181) at org.jboss.ejb.client.EJBInvocationHandler.invoke(EJBInvocationHandler.java:144) at com.sun.proxy.$Proxy4.validateVerificationCode(Unknown Source) ... 13 more Caused by: an exception which occurred: in object of type com.intuism.core.settings.EmbeddedSettings in field defaultSettings in object of type com.intuism.ui.validation.Validation {noformat}