Problem between SWT and Servlet communication

Hi All,

I Am the first time visitor to this group, I am having a small issue.

In our applicaiton we have SWT application talking with Spring web tier through XStream, serialised communication, calling a servlet in Web tier application like below

//Create an instance of HttpClient.
            HttpClient client = getHttpClient();

XStream xstream = new XStream(new DomDriver(ENCODING));
            
            OutputCommand cmdOut = null;

            Object inParam = commandsInParams.get(cmd.getName());

            xstream.alias("InputCommand", InputCommand.class);
            xstream.alias(getSimpleName(inParam), inParam.getClass());
            xstream.alias("CommandError", CommandError.class);

//Execute the method.
                  int statusCode = client.executeMethod(method);

This InputCommand has arraylist of objects contained in it.

Now, the Servlet has a private method which passes the arraylist of objects extracted from request - serialized bean like ..

private void methodName(List params)
{
        ArrayList shortlisted = new Arraylist();
        for (Iterator iterator = params.iterator(); iterator.hasNext();) {
       
           Object xyz = iterator.next();
           if(valid(xyz))
           {
shortlisted.add(xyz);
             
           }

        }
}

The issue is the XStream is throwing the exception that (premature end of input) may be request contents get truncated.. If I change the access modifier to protected it works fine, but Iam not able explain why? to my boss, can you please help