HTTP状态400 - 客户端发送的请求在语法上不正确

Question

我正在尝试在spring mvc中创建一个注册表单。 UserProfile模型负责注册，与Password模型有1对1关系，与Role模型有多对多的关系。

UserProfile模型：

@Entity
@Table(name="user_profile")
public class UserProfile {
    @Id 
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column(name="user_profile_id")
    private Integer userProfileId;

    @Column(name="user_name",length=30,unique=true,nullable=false)
    private String userName;

    @Column(name="first_name")
    private String firstName;

    @Column(name="last_name")
    private String lastName;

    @Column(name="sex")
    private String sex;

    @Column(name="contact")
    private String contact;

    @Column(name="image_path")
    private String imagePath;

    @Column(name="state")
    private String state;

    @ManyToMany(fetch = FetchType.EAGER)
    @JoinTable(name = "role_join_profile", 
         joinColumns = { @JoinColumn(name = "user_profile") }, 
         inverseJoinColumns = { @JoinColumn(name = "role") })
    @Fetch(value = FetchMode.SUBSELECT)
    private List<Role> role = new ArrayList<Role>();

   @OneToOne(cascade = CascadeType.ALL,fetch=FetchType.EAGER)
   @JoinColumn(name="password")
   private Password password;

   @OneToMany(mappedBy="postGiver",fetch=FetchType.EAGER)
   @Fetch(value = FetchMode.SUBSELECT)
   private List<DashBoard> dashBoardList;


   @ManyToMany(fetch = FetchType.EAGER)
   @JoinTable(name = "message_join_user", 
         joinColumns = { @JoinColumn(name = "user_profile") }, 
         inverseJoinColumns = { @JoinColumn(name = "message_id") })
   @Fetch(value = FetchMode.SUBSELECT)
   private List<Message> messageList = new ArrayList<Message>();


   +All attribute's getters & setters


 }

角色模型：

@Entity
@Table(name="role")
public class Role {
      @Id 
      @GeneratedValue(strategy=GenerationType.IDENTITY)
      @Column(name="role_id")
      private Integer roleId;

       +All attribute's getters & setters
}

密码型号：

 @Entity
 @Table(name="password")
 public class Password {
       @Id 
       @GeneratedValue(strategy=GenerationType.IDENTITY)
       @Column(name="password_id")
       private Integer passwordId;

       @Column(name="password")
       private String password;

       +All attribute's getters & setters
  }

如果我发布与UserProfile模型相关的表单，则会显示以下错误

HTTP状态400 - 客户端发送的请求在语法上不正确。

它不会进入控制器的post方法。

当我尝试使用其他模型（如角色模型）时，它可以正常工作。

此UserProfile模型显示错误的问题是什么。

形式：

<form:form action="reg" method="POST" >
<input type="submit"/>**There is no field here cause i just want to hit     
                  controller's method**
</form:form>

控制器的方法：

 @RequestMapping(value="/reg",method = RequestMethod.POST)
 public void reg(Model model,@ModelAttribute UserProfile userProfile){
    System.out.print("sssssss");//this is not being printed,which should be
}