Question

I’m a bit confused about how an object could be edited with Spring Forms, for instance: suppose I have an object Person who has a lot of attributes because I obtain it from a dao, and I only want to provide the field “street” for editing, I would have this in my PeopleController:

@RequestMapping("editPerson")
public void editPerson (Model model) {
    Person person = dao.getThatPerson ();
    model.addAttribute (person);
}

And in my view file I would have nothing but this:

<form:form method="post" action="" commandName="person">
    <form:input path="street" />
    <input type="submit" value="Edit!" />
</form:form>

So when I post the form, will the other attributes of the Person object be preserved? For instance person’s name, surname, username, age, etc. Otherwise, how could this be accomplished?

Answer 1

Store your model object in session, like so:

@Controller
@SessionAttributes("person")
public class YourController {
...
  @ModelAttribute("person")
  public Person getPerson() {
      return new Person();
  }

  @RequestMapping("editPerson")
  public void editPerson (@ModelAttribute("person") Person person) {
    person = dao.getThatPerson ();
  }

  @RequestMapping(value="postperson", method = RequestMethod.POST)
  public void postPerson(@ModelAttribute("person") Person person) {
    // do stuff with person
  }
}