Spring MVC 2.5, binding collection elements and a bottle of Bud in hand

public final class Thing extends AbstractEntity {

  private static final long serialVersionUID = 1L;

  @SuppressWarnings("unchecked")
  public Thing() {
    // let's pretend we have an implementation of the ElementFactory interface
    // which constructs Stuff objects and sets the Thing reference to this
    stuff = new AutoPopulatingList(new StuffFactory(this));
  }
  
  private List<Stuff> stuff;

  public List<Stuff> getStuff() {
    return stuff;
  }

  public void setStuff(final List<Stuff> stuff) {
    this.stuff = stuff;
  }

  // some extra valuable fields and methods reside here

}

public final class Stuff extends AbstractEntity {

  private static final long serialVersionUID = 1L;

  private Thing thing;

  private String value;

  public Thing getThing() {
    return thing;
  }

  public void setThing(final Thing thing) {
    this.thing = thing;
  }

  public String getValue() {
    return value;
  }

  public void setValue(final String value) {
    this.value = value;
  }

}

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %>

<div class="form">
  <form:form commandName="thing" method="post">
    <div>
      <span class="label">Stuff #1</span>
      <span class="field">
        <form:input path="stuff[0].value"/>
      </span>
    </div>
    <div>
      <span class="label">Stuff #2</span>
      <span class="field">
        <form:input path="stuff[1].value"/>
      </span>
    </div>
    <div>
      <span class="label">Stuff #3</span>
      <span class="field">
        <form:input path="stuff[2].value"/>
      </span>
    </div>
  </form:form>
</div>

<c:if test="${not empty things}">
  <c:forEach var="t" items="${things}">
    <div>
      <td><a href="?id=${t.id}">Edit thing with id #${t.id}</a></td><!-- Do not try this at home -->
    </div>
  </c:forEach>
</c:if>

@Controller
public final class ManageThingsController {

  private static final String COMMAND_NAME = "thing";

  // for simplicity's sake I'll just define views here manually,
  // normally you wouldn't do that

  private final String formView = "manageThings";

  private final String successView = "redirect:manageThings";

  private final ThingService thingService;

  @Autowired
  public ManageThingsController(final ThingService thingService) {
    this.thingService = thingService;
  }

  @SuppressWarnings("unused")
  @RequestMapping(method = RequestMethod.GET)
  public String setupForm(@ModelAttribute(COMMAND_NAME) final Thing thing) {
    return formView;
  }

  @RequestMapping(method = RequestMethod.POST)
  public String processSubmit(@ModelAttribute(COMMAND_NAME) final Thing thing) {
    thingService.save(thing);
    return successView;
  }

  @ModelAttribute(COMMAND_NAME)
  public Thing createCommand(@RequestParam(value = "id", required = false) final Integer id) {
    return (id == null) ? new Thing() : thingService.find(id); // normally you wouldn't do this either, but rather 
delegate this to a facade or smth, but "normally" doesn't apply here, sorry
  }

  // one more method will be here shortly

}

// let's conveniently pass our command object there as a parameter

@ModelAttribute("things")
public List<Thing> getThings(@ModelAttribute(COMMAND_NAME) final Thing thing) {
  List<Thing> things = thingService.findAll();

  if (!thing.isNew) {
    things.remove(thing); // this might even work ;D
  }

  return things;
}

@ModelAttribute("things")
public List<Thing> getThings(@RequestParam(value = "id", required = false) final Integer id) {
  List<Thing> things = thingService.findAll();

  if (id != null) {
    for (Iterator<Thing> i = things.iterator(); i.hasNext();) {
      if (id.equals(i.next().getId())) {
        i.remove();
        break;
      }
    }
  }

  return things;
}