Getting java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to [LBlndItmTmMthd

Question

Hi All, I need a serious help in this issue. May be its very basic, but, I am not able to figure it out. I have a session EJB with one method which returns an enum array, i.e. BlndItmTmMthd array. When, I call the method in the client side, it gives me a ClassCastException.

java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to [LBlndItmTmMthd

While debugging, I have found that the ejb method is correctly returning BlndItmTmMthd array by calling BlndItmTmMthd.values(). I am not able to find out the reason. Any idea will be helpful.

Added content from a comment below
AgreementSession.java is the EJB interface which contains the following method declaration:

BlndItmTmMthd[] getAllBlendedItemTimingMethods(); 

AgreementSessionEJB.java is the EJB that implements it.

public BlndItmTmMthd[] getAllBlendedItemTimingMethods() { 
    BlndItmTmMthd[] blendedItemTmingMethods = BlndItmTmMthd.values(); 
    return blendedItemTmingMethods; 
}

Now, at the client side, when I invoke the EJB method with the following code:

BlndItmTmMthd[] _timingMethods = 
             getLoanScheduleSetupSession().getAllBlendedItemTimingMethods(); 

I get that runtime exception.

Answer 1

Given that the error implies that there is a failure to cast objects of type java.lang.Object to the Enum class, I believe there is a failure in the serialization and deserialization process when the response from the EJB is received at the client.

There are a couple of things that you might want to check:

• Is the Enum class BlndItmTmMthd available in the same classloader, or is it loaded twice?
• Does the generated stub of the EJB contain references to the Enum class or to java.lang.Object?

Answer 2

The "[L" in your error tells you the problem - Java is failing to cast an array of Objects (that is, an Object[]) to an array of BlndItmTmMthds (a BlndItmTmMthd[]).

Is BlndItmTmMthd really a java.lang.Enum?

Answer 3

I assume that you have access to both the server and the client code. To trace down this issue you should insert logging statements of the form

logger.info(array.getClass().getCanonicalName());

at all places on the way from the BlndItmTmMthd to the Object. Then you can at least say at which point the conversion happens.