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springrequest-mapping

Would someone answer some questions about Spring and Request Mapping?

I just started studying Spring, and I'm so confused.

I just created a new 'Spring Legacy Project' at STS. HomeController and home.jsp are there.

When I run it on server, it comes through the HomeController first, and arrives to home.jsp.

@RequestMapping(value = "/", method = RequestMethod.GET)
    public String home(Locale locale, Model model) {

        return "home";
    }

  1. What makes my project go through the HomeController at the beginning? Should I look at any xml file?

  2. What does value="/" mean in @RequestMapping?

  3. At the home.jsp, I made a button to go 'result.jsp'. From the 'result.jsp' I want to go back to home.jsp. but it doesn't work. What should I do?

<input type="button" value="뒤로 " onclick="javascript:location.href='/views/home.jsp'">

Why isn't this button working? Those two JSP files are in same place.

Solution

    1. Your app is deployed to some app server, such as tomcat. The request <app server>/<context root> is handled by the app server to the .war with the appropriate context root, e.g. to your app. Your app uses Spring MVC, so it is Spring's RequestMappingHandlerMapping bean from your .war file that initially handles the request and finds your method that will handle this request. It does so by comparing the path in the request with the value of each method annotated with @RequestMapping.

    2. The annotation @RequestMapping(value="/") of your home() method means that request <app server>/<context root> will be handled by your 'home()' method.

    3. Any request from your JSP will go back to the Spring MVC that will try to map it to the appropriate controller method, i.e. to the method annotated by @RequestMapping with the appropriate path relative to the context root. So if your result.jsp just links to "/", it should bring you to the home() method and then to the home.jsp.