Scope prototype bean scope not creating new bean

Question

I want to use a annotated prototype bean in my controller  But spring is creating a singleton bean instead  Here is the code for that    Component  Scope  prototype   public class LoginAction      private int counter     public LoginAction        System out println   counter is     counter         public String getStr         return   counter is      counter           Controller code    Controller public class HomeController        Autowired     private LoginAction loginAction        RequestMapping value   view   method RequestMethod GET      public ModelAndView display HttpServletRequest req           ModelAndView mav   new ModelAndView  home            mav addObject  loginAction   loginAction           return mav             public void setLoginAction LoginAction loginAction            this loginAction   loginAction             public LoginAction getLoginAction             return loginAction                Velocity template    LoginAction counter    loginAction str    Spring config xml has component scanning enabled          lt context annotation-config   gt       lt context component-scan base-package  com springheat    gt       lt mvc annotation-driven   gt    I m getting an incremented count each time  Can t figure out where am I going wrong    Update  As suggested by  gkamal  I made HomeController webApplicationContext-aware and it solved the problem   updated code    Controller public class HomeController         Autowired     private WebApplicationContext context        RequestMapping value   view   method RequestMethod GET      public ModelAndView display HttpServletRequest req           ModelAndView mav   new ModelAndView  home            mav addObject  loginAction   getLoginAction             return mav             public LoginAction getLoginAction             return  LoginAction  context getBean  loginAction

User · Answer

Using ApplicationContextAware is tying you to Spring  which may or may not be an issue    I would recommend passing in a LoginActionFactory  which you can ask for a new instance of a LoginAction each time you need one

User · Answer

A protoype bean injected inside a singelton bean will behave like singelton untill expilictly called for creating a new instance by get bean   context getBean  Your Bean

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Component   Scope value  prototype    public class TennisCoach implements Coach       some code

User · Answer

Since Spring 2 5 there s a very easy  and elegant  way to achieve that   You can just change the params proxyMode and value of the  Scope annotation   With this trick you can avoid to write extra code or to inject the ApplicationContext every time that you need a prototype inside a singleton bean   Example    Service   Scope value  prototype   proxyMode ScopedProxyMode TARGET CLASS    public class LoginAction      With the config above LoginAction  inside HomeController  is always a prototype even though the controller is a singleton

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By default  Spring beans are singletons  The problem arises when we   try to wire beans of different scopes  For example  a prototype bean   into a singleton  This is known as the scoped bean injection problem    Another way to solve the problem is method injection with the  Lookup annotation   Here is a nice article on this issue of injecting prototype beans into a singleton instance with multiple solutions   https   www baeldung com spring-inject-prototype-bean-into-singleton

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controller is a singleton object  and if  inject a prototype bean to a singleton class will make the prototype bean also as singleton unless u specify using lookup-method property which actually create a new instance of prototype bean for every call you make

User · Answer

As mentioned by nicholas hauschild injecting Spring context is not a good idea  In your case   Scope  request   is enough to fix it  But let say you need several instances of LoginAction in controller method  In this case  I would recommend to create the bean of Supplier  Spring 4 solution         Bean     public Supplier lt LoginAction gt  loginActionSupplier LoginAction loginAction           return    - gt  loginAction          Then inject it into controller    Controller public class HomeController        Autowired     private  Supplier lt LoginAction gt  loginActionSupplier

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Just because the bean injected into the controller is prototype-scoped doesn t mean the controller is

User · Answer

use request scope  Scope  request   to get bean for each request  or  Scope  session   to get bean for each session  user

User · Answer

You can create static class inside your controller like this         Controller     public class HomeController            Autowired         private LoginServiceConfiguration loginServiceConfiguration            RequestMapping value     view   method   RequestMethod GET          public ModelAndView display HttpServletRequest req                ModelAndView mav   new ModelAndView  home                mav addObject  loginAction   loginServiceConfiguration loginAction                 return mav                       Configuration         public static class LoginServiceConfiguration                 Bean name    loginActionBean                Scope  prototype               public LoginAction loginAction                     return new LoginAction

User · Answer

Your controller also need the  Scope  prototype   defined  like this    Controller  Scope  prototype   public class HomeController

User · Answer

Scope prototype means that every time you ask spring  getBean or dependency injection  for an instance it will create a new instance and give a reference to that   In your example a new instance of LoginAction is created and injected into your HomeController   If you have another controller into which you inject LoginAction you will get a different instance   If you want a different instance for each call - then you need to call getBean each time - injecting into a singleton bean will not achieve that

[spring] @Scope("prototype") bean scope not creating new bean

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