Strange Behavior of BeanCreationExceptio

[vidhuz]

Hi Folks,

I am encountering a very strange problem (well I don't know it is a problem or a conceptual issue at this point). I am having a Spring Managed SLSB deployed on one of our servers. The ApplicationContext.xml file (specified in "ejb/BeanFactoryPath" enviro var is missing some classpath resource)

I have got one local client to test it. The SLSB is having some configuration error in its ApplicationContext.xml, so it throws a Remote Exception, with BeanCreationException as initCause to it, everytime a call is made to it (which is very well expected).

The point to ponder here is that if I have the same Spring JAR in my classpath then it says:

java.io.InvalidClassException: org.springframework.beans.BeansException; local class incompatible: stream classdesc serialVersionUID = 5951866628951717299, local class serialVersionUID = -2725566157126749441


If i remove the Spring JAR from the classpath and try to introspect on the initCause of the RemoteException (which is BeanCreationException), surprisingly I am able to see all the public methods declared in the class!

Then if I try to invoke one (say getResourceDescription) method on the BeanCreationException instance, it actually allows me to that (printing "class path resource [ApplicationContext.xml]" on the console). What I am wondering is that how can unmarshalling happen on a Object whose class we are not having in the classpath (and we are having an object of that class on the heap)?

Lastly, I put my Java notions aside to write a custom class, MyException extending RuntimeException and serialized it to a file "C://exception.ser". Now i try to deserialize this object on a separate project which is not having MyException in the classpath, I get a java.lang.ClassNotFoundException straightaway at the very place I try to do a objectInputStream.readObject().


Could anybody put a insight on this? Source of all the stated files are below:


MyException Class doing serialization as well

package com.test;

import java.io.FileOutputStream;
import java.io.ObjectOutputStream;
import java.rmi.RemoteException;

@SuppressWarnings("serial")
public class MyException extends RuntimeException {

	public MyException() {
	}

	public MyException(String message) {
		super(message);
	}

	public MyException(Throwable cause) {
		super(cause);
	}

	public MyException(String message, Throwable cause) {
		super(message, cause);
	}
	
	public String getAmazingMessage() {
		return "Whoa!";
	}
	
	public static void main(String[] args) throws Exception {
		System.out.println("Serializing an instance of MyException");
		String path = "C://exception.ser";
		MyException exception = new MyException("This is gonna deserialize!");
		ObjectOutputStream objectOutputStream = new ObjectOutputStream(new FileOutputStream(path));
		objectOutputStream.writeObject(new RemoteException("RemoteException", exception));
//		objectOutputStream.writeObject(exception); // This cause the same output
		objectOutputStream.flush();
		objectOutputStream.close();
		System.out.println("An instance of MyException serialized at " + path);

//		This thing completes normally 
	}

}

Deserialization of MyExceptionClass

package com.test;

import java.io.FileInputStream;
import java.io.ObjectInputStream;
import java.lang.reflect.Method;


public class TestDeser {
		public static void main(String[] args) throws Exception {
			String path = "C://exception.ser";
			ObjectInputStream objectInputStream = new ObjectInputStream(new FileInputStream(path));
			Object object = objectInputStream.readObject(); // Exception comes right here
			Class clazz = object.getClass();
			System.out.println("Class of Object: " + clazz);
			System.out.println("Name of Object: " + clazz.getName());
	//		Class.forName(clazz.getName());
			Method[] methods = clazz.getMethods();
			for (Method method : methods) {
				System.out.println(method.getName());
				if(method.getName().equals("getAmazingMessage")) {
					Object returnValue = method.invoke(object, (Object[])null);
					System.out.println("Invoking getAmazingMessage() on bean returned: " + returnValue);
				}
			}
		}
}

Service Client

package com.test;

import java.lang.reflect.Method;
public class ServiceClient {


	public static void main(String[] args) throws Exception{
		System.out.println("Calling DID Manager under try-catch ...");
		
		try {
			ServicerLocator service = new ServicerLocator();
			service.getAccountInfo(3584);
		} catch (Exception e) {
			Throwable cause = e.getCause();
			Class<? extends Throwable> bceClass = cause.getClass();
			System.out.println("Class of the Nested Exception: " + bceClass);
			System.out.println("Name of the Nested Exception Class: " + bceClass.getName());
//			Class.forName(bceClass.getName());
			Method[] methods = bceClass.getMethods();
			for (Method method : methods) {
				System.out.println(method.getName());
				if(method.getName().equals("getResourceDescription")) {
					Object returnValue = method.invoke(cause, (Object[])null);
					System.out.println("Invoking getResourceDescription() on bean returned: " + returnValue);
				}
			}
		}
	}

}

[vidhuz]

Could any spring community member answer this question please?

[jalbert]

My friend, it is very likely that you already solve your problem, I am posting that for help some one else.

Today thats happends to me and the mistake were in the versions of Spring that I was using, I had spring-core 2.5.6 and the others Spring´s librarys were 2.5.3