How to use Session attributes in Spring-mvc

Question

Could you help me write spring mvc style analog of this code    session setAttribute  name   value      And how to add an element that is annotated by  ModelAttribute annotation to session and then get access to it

User · Answer

In Spring 4 Web MVC  You can use  SessionAttribute in the method with  SessionAttributes in Controller level   Controller  SessionAttributes  SessionKey   public class OrderController extends BaseController        GetMapping   showOrder       public String showPage  SessionAttribute  SessionKey   SearchCriteria searchCriteria            method body

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If you want to delete object after each response you don t need session   If you want keep object during user session   There are some ways    directly add one attribute to session    RequestMapping method   RequestMethod GET  public String testMestod HttpServletRequest request      ShoppingCart cart    ShoppingCart request getSession   setAttribute  cart  value      return  testJsp       and you can get it from controller like this    ShoppingCart cart    ShoppingCart session getAttribute  cart     Make your controller session scoped   Controller  Scope  session    Scope the Objects  for example you have user object that should be in session  every time    Component  Scope  session   public class User        String user          setter getter         then inject class in each controller that you want      Autowired    private User user   that keeps class on session  The AOP proxy injection   in spring -xml    lt beans xmlns  http   www springframework org schema beans    xmlns xsi  http   www w3 org 2001 XMLSchema-instance    xmlns aop  http   www springframework org schema aop    xsi schemaLocation  http   www springframework org schema beans     http   www springframework org schema beans spring-beans-3 1 xsd     http   www springframework org schema aop     http   www springframework org schema aop spring-aop-3 1 xsd  gt      lt bean id  user     class  com User  scope  session  gt              lt aop scoped-proxy  gt     lt  bean gt   lt  beans gt    then inject class in each controller that you want   Autowired private User user    5 Pass HttpSession to method      String index HttpSession session                session setAttribute  mySessionAttribute    someValue                return  index               6 Make ModelAttribute in session By  SessionAttributes  ShoppingCart       public String index   ModelAttribute  ShoppingCart   ShoppingCart shoppingCart  SessionStatus sessionStatus      Spring V4   you can modify session status  by sessionStatus setComplete        or you can add Model To entire Controller Class like      Controller      SessionAttributes  ShoppingCart        RequestMapping   req       public class MYController             ModelAttribute  ShoppingCart           public Visitor getShopCart                      return new ShoppingCart          get From DB Or Session                       each one has advantage and disadvantage    session may use more memory in cloud systems it copies session to all nodes  and direct method  1 and 5  has messy approach  it is not good to unit test   To access session jsp    lt   session getAttribute  ShoppingCart prop    gt    in Jstl     lt c out value    sessionScope ShoppingCart prop    gt    in Thymeleaf    lt p th text    session ShoppingCart prop   th unless    session    null   gt     lt  p gt

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Isn t it easiest and shortest that way  I knew it and just tested it - working perfect here    GetMapping public String hello HttpSession session        session setAttribute  name   value        return  hello       p s  I came here searching for an answer of  How to use Session attributes in Spring-mvc   but read so many without seeing the most obvious that I had written in my code  I didn t see it  so I thought its wrong  but no it was not  So lets share that knowledge with the easiest solution for the main question

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When I trying to my login  which is a bootstrap modal   I used the  sessionattributes annotation  But problem was when the view is a redirect   redirect  home    values I entered to session shows in the url  Some Internet sources suggest to follow http   docs spring io spring docs 4 3 x spring-framework-reference htmlsingle  mvc-redirecting But I used the HttpSession instead  This session will be there until you close the browsers  Here is sample code            RequestMapping value     login            ResponseBody         public BooleanResponse login HttpSession session HttpServletRequest request                 HttpServletRequest used to take data to the controller             String username   request getParameter  username                String password   request getParameter  password                  Here you set your values to the session            session setAttribute  username   username              session setAttribute  email   email                your code goes here     You don t change specific thing on view side    lt c out value    username   gt  lt  c out gt   lt c out value    email   gt  lt  c out gt    After login add above codes to anyplace in you web site  If session correctly set  you will see the values there  Make sure you correctly added the jstl tags and El- expressions  Here is link to set jstl tags https   menukablog wordpress com 2016 05 10 add-jstl-tab-library-to-you-project-correctly

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Try this      Controller  RequestMapping   owners  ownerId  pets  petId  edit    SessionAttributes  pet   public class EditPetForm         ModelAttribute  types        public Collection lt PetType gt  populatePetTypes             return this clinic getPetTypes                RequestMapping method   RequestMethod POST      public String processSubmit  ModelAttribute  pet   Pet pet               BindingResult result  SessionStatus status            new PetValidator   validate pet  result           if  result hasErrors                  return  petForm            else               this clinic storePet pet               status setComplete                return  redirect owner do ownerId                     pet getOwner   getId

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SessionAttribute annotation is the simplest and straight forward instead of getting session from request object and setting attribute  Any object can be added to the model in controller and it will stored in session if its name matches with the argument in  SessionAttributes annotation   In below eg  personObj will be available in session    Controller  SessionAttributes  personObj   public class PersonController         RequestMapping value   person-form       public ModelAndView personPage             return new ModelAndView  person-page    person-entity   new Person                 RequestMapping value   process-person       public ModelAndView processPerson  ModelAttribute Person person            ModelAndView modelAndView   new ModelAndView            modelAndView setViewName  person-result-page             modelAndView addObject  pers   person           modelAndView addObject  personObj   person            return modelAndView

User · Answer

Use This method very simple easy to use  HttpServletRequest request    HttpServletRequest  context getExternalContext   getNativeRequest                                                                 request getSession   setAttribute  errorMsg    your massage      in jsp  once use then remove   lt c remove var  errorMsg  scope  session   gt

User · Answer

Use  SessionAttributes  See the docs  Using  SessionAttributes to store model attributes in the HTTP session between requests   Understanding Spring MVC Model And Session Attributes  also gives a very good overview of Spring MVC sessions and explains how when  ModelAttributes are transferred into the session  if the controller is  SessionAttributes annotated    That article also explains that it is better to use  SessionAttributes on the model instead of setting attributes directly on the HttpSession because that helps Spring MVC to be view-agnostic

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The below annotated code would set  value  to  name    RequestMapping   testing    Controller public class TestController    RequestMapping method   RequestMethod GET  public String testMestod HttpServletRequest request       request getSession   setAttribute  name    value        return  testJsp           To access the same in JSP use    sessionScope name    For the  ModelAttribute see this link

[spring-mvc] How to use Session attributes in Spring-mvc

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