Spring MVC Anwendung: Verbindliche viele-zu-viele-list-Objekt in form

Mein Spring MVC web-Anwendung macht Gebrauch von zwei Modell-Klassen Spieler und Mannschaft. Es ist ManyToMany Beziehung zwischen Spieler und Team. Hier sind die Modell-Klassen.

    @Entity
    @Table(name="TEAMS")
    public class Team {
            @Id
            @Column(name="ID")

            private int id;

            @Column(name="NAME")
            @Size(min=2, max=30)
            private String name;

            @ManyToMany(mappedBy="teams")
            private Set<Player> players = new HashSet<Player>();
                //getter and setter methods

    }

@Entity

    @Table(name="PLAYERS")
    public class Player {

        @Id
        @Column(name="ID")
        @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="players_seq")
        @SequenceGenerator(name="players_seq", sequenceName="PLAYERS_SEQ")
        private int id;

        @Column(name="LASTNAME")
        @Size(min=2, max=30)
        private String lastname;

        @Column(name="FIRSTNAME")
        @Size(min=2, max=30)
        private String firstname;

        @Column(name="BIRTHDAY")
        @DateTimeFormat(pattern="MM/dd/yyyy")
        @NotNull @Past
        private Date dob;

        @Column(name="PLAYING_ROLE")
        @NotNull
        private String playingRole;

        @ManyToMany(cascade =CascadeType.ALL)
        @JoinTable(name="TEAM_PLAYER", 
        joinColumns={@JoinColumn(name="PLAYER_ID")},
        inverseJoinColumns={@JoinColumn(name="TEAM_ID")})
        private Set<Team> teams = new HashSet<Team>();
    //getter and setters
    }

Ich versuche mich zu ordnen-team auf Spieler mit Hilfe der Checkboxen und meine JSP sieht wie folgt aus

<table>
        <form:form modelAttribute="player" method="POST"
            action="${editPlayer }">
            <tr>
                <td>Last name:</td>
                <td><form:input path="lastname" /> <form:errors
                        path="lastname" cssStyle="color:red;" /></td>
            </tr>
            <tr>
                <td>First Name:</td>
                <td><form:input path="firstname" /> <form:errors
                        path="firstname" cssStyle="color:red;" /></td>
            </tr>
            <tr>
                <td>Birthday:</td>
                <td><form:input path="dob" /> <form:errors path="dob"
                        cssStyle="color:red;" /></td>
            </tr>
            <tr>
                <td>Playing Style:</td>
                <td><form:input path="playingRole" /> <form:errors
                        path="playingRole" cssStyle="color:red;" /></td>
            </tr>

            <tr>
                <td>Teams:</td>
                <td><form:checkboxes items="${teams}" path="teams"
                        itemValue="id" itemLabel="name" /></td>
            </tr>

            <tr>
                <td colspan="2"><input type="submit" value="Update Player" /></td>
            </tr>
        </form:form>
    </table>

Meine PlayerController.java sieht so aus

@Controller
public class PlayerController {

    @Autowired
    private PlayerService playerService;

    @Autowired
    private TeamService teamService;

    @ModelAttribute("teams")
    public List<Team> getTeams(){
        return teamService.getTeams();
    }
@RequestMapping(value="/player/edit/{id}", method=RequestMethod.GET)
    public ModelAndView updatePlayerPage(@PathVariable int id){
        Player player = playerService.getPlayer(id);
        ModelAndView modelAndView = new ModelAndView("player/edit");
        modelAndView.addObject("player", player);
        return modelAndView;
    }

    @RequestMapping(value="/player/edit/{id}", method=RequestMethod.POST)
    public ModelAndView updatePlayer(@ModelAttribute @Valid Player player, BindingResult result, @PathVariable int id){
        if(result.hasErrors()){

            System.out.println("HAS ERRORS!. Number of errors: "+result.getAllErrors().size());
            for(Object o : result.getAllErrors()){
                System.out.println(o);
            }
            System.out.println("\n Player details: "+ player );
            return new ModelAndView("player/edit");
        }
        playerService.updatePlayer(player);
        ModelAndView modelAndView = new ModelAndView("home");
        String message = "Player updated successfully";
        modelAndView.addObject("message", message);
        return modelAndView;
    }

//it has got some other methods also that does some other functionality

}

JSP-Seite wird immer richtig dargestellt, aber wenn ich versuche zu speichern, erhalte ich die exception

 Field error in object 'player' on field 'teams': rejected value [5050]; codes [typeMismatch.player.teams,typeMismatch.teams,typeMismatch.java.util.Set,typeMismatch]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [player.teams,teams]; arguments []; default message [teams]]; default message [Failed to convert property value of type 'java.lang.String' to required type 'java.util.Set' for property 'teams'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [org.sunil.model.Team] for property 'teams[0]': no matching editors or conversion strategy found]

Grund für die Ausnahme ist, dass ich zuweisen müssen Team-Player, aber ich bin nicht sicher, wie dies zu tun. Kann mir bitte jemand helfen heraus, wie diese zu lösen.

Dank