Get ApplicationContext (@AutoWired, Applicationlistener) in spring code

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Learning Spring frame time is not long, every bit has to be pro-force. Today, I suddenly feel that the automatic loading of components through the @autowired is not very comfortable, always want to write annotations under the class. So consider getting applicationcontext directly, calling Getbean to get the bean instance you want. On-line data, the beginning of the wrong direction, through the way of loading XML initialization ApplicationContext, it is a ridiculous process, we are obviously blind to engage in. The following is about what I learned now, two kinds: 1, with @autowired directly assembled applicationcontext;2, with Applicationlistener monitoring contextrefreshedevent events, when the context is refreshed, Save the ApplicationContext to the global object.

First, with @autowired directly assembled ApplicationContext. Simple, simple to put down the code.

     @Autowired    applicationcontext context;         = "/login2")    public  String login2 (string name, model model, HttpServletRequest request, HttpSession session) {                context.getbean (requestbean.  Class). Printid ();

Second, monitor contextrefreshedevent events with Applicationlistener. Individuals prefer this implementation by not having to write @autowired annotations, and then continue to use spring to automate the management of components.

Simple description: Applicationlistener is an application event watcher, can listen to applicationevent of various extension classes, this is very interesting, we can define their own events, Then use Applicationlistener to monitor. Attach a bit of source code below

　　

1. Define a context management tool (global use)

 Packagesimm.spring.common.utils;ImportOrg.springframework.context.ApplicationContext;/*** Context Acquisition Tool class *@authorWh-simm **/ Public classApplicationcontextutil { Public StaticApplicationcontextutil instance =NewApplicationcontextutil (); PrivateApplicationContext _context; PrivateApplicationcontextutil () {} Public voidinit (ApplicationContext context) {_context=context; }     PublicApplicationContext GetContext () {return_context; }    /*** Get Bean *@paramRequiredtype *@return     */     Public<T> T Getbean (class<t>requiredtype) {        return_context.getbean (requiredtype); }}

2, the implementation of the context of the completion of the initialization or refresh of the listening method, ApplicationContext to obtain and save

 Packagesimm.spring.web.events;ImportOrg.springframework.context.ApplicationListener;Importorg.springframework.context.event.ContextRefreshedEvent;ImportOrg.springframework.stereotype.Service;Importsimm.spring.common.utils.ApplicationContextUtil; @Service Public classContextrefreshlistenerImplementsApplicationlistener<contextrefreshedevent>{@Override Public voidonapplicationevent (Contextrefreshedevent event) {//TODO auto-generated Method Stub        if(Event.getapplicationcontext (). GetDisplayName (). Equals ("Root webapplicationcontext") {System.out.println ("Avoid spring-servlet.xml and appicationcontext.xml two times"); }        if(Event.getapplicationcontext (). getParent () = =NULL) {System.out.println ("Perform context contexts initialization");        ApplicationContextUtil.instance.init (Event.getapplicationcontext ()); }    }}

3. Next, show the new calling method. Now this call will no longer have to consider whether the successful completion of the @autowired, in the business code can be used freely. There is wood to feel a hint of refreshing!

ApplicationContextUtil.instance.getBean (Requestbean.  Class). Printid ();

This is a bit of my experience with ApplicationContext. Not many things, I hope you have some help, welcome message exchange.

Get ApplicationContext (@AutoWired, Applicationlistener) in spring code