How to prioritize interceptors in Spring web mvc

Question

I have three interceptors in my application and i just want to prioritize them, actually i want to auto login my application from another application via query params.

This interceptor is validating the user session if user doesn't have valid session then it will redirect user to login page and it is working fine.

public class ValidateSessionInterceptor extends HandlerInterceptorAdapter {

    private Logger log = Logger.getLogger(getClass());

    @Value("${http.port}")
    private int httpPort;

    @Value("${https.port}")
    private int httpsPort;

    @Value("${use.ssl}")
    private boolean useSsl;

    //before the actual handler will be executed
    public boolean preHandle(HttpServletRequest request,HttpServletResponse response, Object handler) throws Exception {    
        HttpSession session = request.getSession();     

        if(session.getAttribute("user")==null){         
            String forwardTo = (String) request.getAttribute("org.springframework.web.servlet.HandlerMapping.pathWithinHandlerMapping");
            String params = "";

            if(request.getQueryString()!=null){
                params = "?" + request.getQueryString();
            }

            String url = getApplicationUrl(request,useSsl)+forwardTo+params;
            log.info("redirect url: " + request.getContextPath()+"/login/index.mars?forwardTo="+URLEncoder.encode(url, "UTF-8"));
            response.sendRedirect(request.getContextPath()+"/login/index.mars?forwardTo="+URLEncoder.encode(url, "UTF-8"));
            return false;           
        }else{
            Map<String,String> owners = new LinkedHashMap<String,String>();
            owners.put("NA", "NA");
            owners.put("AK", "AK");
            request.setAttribute("ownerList", owners);
        }

        return true;
    }

    private String getApplicationUrl(HttpServletRequest request,boolean useSsl){
        if(useSsl){
            return "https://"+request.getServerName()+":"+httpsPort+request.getContextPath();
        }else{
            return "http://"+request.getServerName()+":"+httpPort+request.getContextPath();
        }
    }
}

This is being called by another application and passing autoUsr and autoPwd parameters to auto logged in application.

public class AutoLoginInterceptor extends HandlerInterceptorAdapter{
    private final Logger log = Logger.getLogger(getClass());

    @Autowired
    public UserService userService;

    @Autowired
    public WebService webService;


    public boolean preHandle(HttpServletRequest request,HttpServletResponse response, Object handler) throws IOException, UserException {
        HttpSession session = request.getSession();

        if(session.getAttribute("user")==null){
            String forwardTo = request.getParameter("forwardTo");
            if(forwardTo!=null && !forwardTo.equals("")){               
                User user = checkLoginCrendential(forwardTo);
                log.info("user-> " + user);
                this.webService.buildWebService(request);
                if(userService.login(request, user)){
                    session.setAttribute("user", user);
                    return true;
                }   
            }       
        }

        return true;
    }

    public User checkLoginCrendential(String url){      
        String decURL;

        User user = new User();
        try 
        {
            decURL = URLDecoder.decode(url,"utf-8");
            String params[] = (decURL.split("\\?")[1]).split("&");
            String loginParams[] = {"autoUsr","autoPwd"};


            for(String lgnParam : loginParams){
                for(int i = 0 ; i < params.length ; i++){
                    String param[] = params[i].split("=");
                    if(lgnParam.equals(param[0])){
                        if(param.length > 1){                           
                            if(lgnParam.equals("autoUsr")){
                                user.setUsername(param[1]);
                            }else if(lgnParam.equals("autoPwd")){
                                user.setPassword(param[1]);
                            }
                        }else{
                            if(lgnParam.equals("autoUsr")){
                                user.setUsername("");
                            }else if(lgnParam.equals("autoPwd")){
                                user.setPassword("");
                            }
                        }

                    }
                }
            }
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }       

        return user;
    }
}

Answer 1

You can use tag to order interceptors in XXX-servlet.xml. For example :

<mvc:interceptors>
  <mvc:interceptor>
    <mvc:mapping path="/**" />
    <bean class="ValidateSessionInterceptor" />
  </mvc:interceptor>
  <mvc:interceptor>
    <mvc:mapping path="/**" />
    <bean class="AutoLoginInterceptor" />
  </mvc:interceptor>
</mvc:interceptors>

interceptors will be called by order