How to get data from a HTML form in Spring MVC Controller?

[Anupam Dee]

I am new to Spring MVC.
I am facing a simple problem but unable to understand how to do it.
I have a simple form containing an input field and a submit button. All i have to do is to enter the userid in the field and hit enter.. and the user with that id shows up.

But how to get the request parameters in the Controller class ?
i am not able to understand the @ModelAttribute annotation also..
Why should we use this annotation?
Please help me.

Thanks

[Jeanne Boyarsky]

This example from the Spring tutorial shows using the @RequestParam annotation to map HTML form parameters to the method signature. In this case, "petId" is the name of the field on the HTML form.

@Controller
@RequestMapping("/pets")
@SessionAttributes("pet")
public class EditPetForm {

    // ...

    @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";
    }

[Jeanne Boyarsky]

Anupam Dee wrote: am not able to understand the @ModelAttribute annotation also..

Missed this on first read. This thread explains it well.

[Bill Gorder]

Here is another good tutorial to get you started.

http://krams915.blogspot.com/2010/12/spring-3-mvc-using-modelattribute-in.html

[Sindhu Kodoor]

I have done a POC today by following this one :
http://www.mkyong.com/spring-mvc/spring-mvc-form-handling-annotation-example/
hope it benefits you !

[Anupam Dee]

Thank you everyone.
I still have a lot of confusions. But I ll ask them one by one and get them clear.
Thanks once again