Spring MVC Web PetClinic Tutorial?

Is there a tutorial that goes along with the PetClinic application? I have been trying to find one, but google is not helping me today. Specifically, I dont understand things like:

@Autowired - what does that even mean?

@RequestMapping(method = RequestMethod.GET)
public String setupForm(@RequestParam("petId") int petId, ModelMap model) {
    Pet pet = this.clinic.loadPet(petId);
    model.addAttribute("pet", pet);
    return "petForm";
}

How can a request return just a string? Shouldnt it need to return some sort of ModelAndView? Or does the application somehow redirect to whatever is returned?

A lot of confusing concepts - if there is a tutorial, or video 开发者_如何学C(like spring-security has) that would be very helpful. Thanks.

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Autowired is Dependency injection. It creates beans for you and sets them.

In this example the controller is returning a String that is the name of the view. It's basically the same thing as

return new ModelAndView("petForm"); 

It could map to something else or it could be as simple as returning petForm.jsp. Depends on the View Resolver.

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It is returning the exact name of the view, so you could expect this to redirect you to the view located at /WEB-INF/jsp/petForm.jsp which will have access to the pet model