Concurrent post and get Spring MVC

I have to send some data in the server and i manage to do this succesfully.Now when i send this data the server sends me a reply.The reply contains a new field (which i need to extract it) + the data i send.

@RequestMapping(value = "/send", method = RequestMethod.POST)
public String setForm(@ModelAttribute("Attribute") AClass aclass,Model model){

HttpEntity<AClass> entity = new HttpEntity<AClass>(aclass,headers);

try {
ResponseEntity<AClass> result = template.exchange(URL,
HttpMethod.POST, entity, AClass.class);

model.addAttribute("IdUser", result.getBody());

} catch (Exception e) {
}
return "aview"

}
In the above code the IdUser contains the data i send.But i want to get the server response data instead only of the data i send. Is it possible to retrieve the automatic server response?I'm using the JAXB annotations for binding the request/response.

The model is something like this:

@XmlRootElement(name="send")
public class AClass{

@XmlElement
private String password;
@XmlElement
private String username;

get/set
}
So the xml i send has this form:

<send>
<password> </password>
<username> </username>
</send>
The form of the XMl the server sends to me after a successful post has this form:

<send>
<id> </id>
<password> </password>
<username> </username>
</send>
The password and the username is the same as those i send. The new element i need to retrieve is the id.I don't know what should i do.Please provide opinions