Problem with GWT and ClassCastException

Hello,

I'm having a problem casting cast from an object in GWT. I have a public <T> T getInstance(Class<T> clazz, String code,String packageName) method which, upon receiving a class, a code and a package name, generates an instance of the passed code and converts it to the type of the parameter class with the package also supplied. Here's the implementation:

public <T> T getInstance(Class<T> clazz, String code,String packageName) 
        throws IOException, InstantiationException, IllegalAccessException, NameNotFoundException {
    final String name =  getClassName(code);
    final Path wrappedCodede = wrapCode(packageName, name, code);
    final Path classFile = compile(wrappedCodede);
    final ClassLoaderFromTemp loader = new ClassLoaderFromTemp();
    final Class<?> p1Class = loader.findClassInTemp(classFile);
    final Object instace = p1Class.newInstance();

    cleanupTmp();

    return clazz.cast(instace);
}

When I call this method by passing the code to be compiled and instantiated through GWT, I get a ClassCastException exception thrown at clazz.cast(instace) . However, it would be plausible for such an exception to be launched if it were not for the following reasons which contradict it:

• Both the class passed by parameter and the superclass of the generated instance of the code are the same.
• Calling the same method, however outside of GWT (by a main method in the context of a Java Application execution) works without any problem. See below an example of a method call that does not throw the exception.

Calling the method outside GWT:

public static void main(String[] args) {        
    try {
        AgentBuilder.addToClassPath("src");
        AgentBuilder ab = new AgentBuilder();
        ab.getInstance(Ship.class, CODE, "Teste");          
    } catch (Exception e) {
        System.out.println(e.getMessage());
    }       
}

Now see a method that throws the exception, but only if executed as a Web Application next to GWT:

void checkCode() throws SoncException {
    try {
        AgentBuilder agentBuilder = new AgentBuilder();
        agentBuilder.getInstance(Ship.class, this.code, this.nick);
    } catch (IOException | InstantiationException | IllegalAccessException | NameNotFoundException
            | NullPointerException | ClassCastException e) {
        throw new SoncException("An error occurred on checking player's code.", e);
    }
}

For both the first and second method, consider the argument code passed in the call of getInstance as import sonc.battle.Ship; public class EmptyShip extends Ship {} .

Would anyone have any idea why this exception should be thrown in one case and the other not?

Thanks for the help, guys.