I have a controller that calls an external webservice (WS). When it calls the WS but this doen´t process anything because it´s already updated, it returns OK(200) and my controller returns success (AJAX). However, if the WS has to process an update and it takes a few minutes (not too long), it still returns OK(200) but my controller returns ERROR 500.
I also try calling the controller with a submit button, instead of AJAX, with the same result.

Hope I have explained well. Can anyone help?

callWebService controller

@PostMapping(value = "/xyz.htm", params="callWebService")
@ResponseBody
public String callWebService(final HttpSession session, HttpServletRequest request) {   
        
    String resultado="{"messageType":"error","message":"Updated error"}";

    try {
        SendNotification sendNotification = new SendNotification();
        if (SendNotification.send()) {
            resultado="{"messageType":"info","message":"Updated"}";
        }   
    }catch (Exception e) {
        logger.error("xyz.callWebService -- Error calling WS", e);
    }
    return resultado;
}

SendNotification class

public boolean send() throws Exception {
    String token = getToken();
    if (token != null && !token.isEmpty()) {
         Client client = null;
         WebTarget myResource = null;
         Response res = null;
 
         try {
             client = ClientBuilder.newBuilder().sslContext(Conexiones.configurarSSL()).build();
             myResource = client.target(urlAvisos);
             Invocation.Builder builder = myResource.request(MediaType.APPLICATION_JSON);
             builder.header(HttpHeaders.AUTHORIZATION, "Bearer " + token);
             res = builder.post(Entity.entity("{}", MediaType.APPLICATION_JSON));
             if (res.getStatusInfo().getReasonPhrase().equalsIgnoreCase("ok")) {
                logger.error("sent - OK");
                return true;
             } else {
                logger.error("sent- not OK");
                return false;
             }

         } catch (Exception ex) {
             logger.error("SendNotification.send", ex);
         } finally {
             if (res != null) {
                 res.close();
             }
             if (client != null) {
                 client.close();
             }
         }
     } else {
        return false;
     }
 }