我有這樣的模型類，用于休眠@Entity@Table(name = "user", catalog = "userdb")@JsonIgnoreProperties(ignoreUnknown = true)public class User implements java.io.Serializable {    private Integer userId;    private String userName;    private String emailId;    private String encryptedPwd;    private String createdBy;    private String updatedBy;    @Id    @GeneratedValue(strategy = IDENTITY)    @Column(name = "UserId", unique = true, nullable = false)    public Integer getUserId() {        return this.userId;    }    public void setUserId(Integer userId) {        this.userId = userId;    }    @Column(name = "UserName", length = 100)    public String getUserName() {        return this.userName;    }    public void setUserName(String userName) {        this.userName = userName;    }    @Column(name = "EmailId", nullable = false, length = 45)    public String getEmailId() {        return this.emailId;    }    public void setEmailId(String emailId) {        this.emailId = emailId;    }    @Column(name = "EncryptedPwd", length = 100)    public String getEncryptedPwd() {        return this.encryptedPwd;    }   在Spring MVC控制器中，使用DAO，我可以獲取對象。并返回為JSON對象。@Controllerpublic class UserController {    @Autowired    private UserService userService;    @RequestMapping(value = "/getUser/{userId}", method = RequestMethod.GET)    @ResponseBody    public User getUser(@PathVariable Integer userId) throws Exception {        User user = userService.get(userId);        user.setCreatedBy(null);        user.setUpdatedBy(null);        return user;    }}視圖部分是使用AngularJS完成的，因此它將獲得像這樣的JSON{  "userId" :2,  "userName" : "john",  "emailId" : "john@gmail.com",  "encryptedPwd" : "Co7Fwd1fXYk=",  "createdBy" : null,  "updatedBy" : null}如果我不想設(shè)置加密的密碼，則將該字段也設(shè)置為null。但是我不想這樣，我不想將所有字段發(fā)送到客戶端。如果我不希望發(fā)送密碼，updatedby，createdby字段，則我的結(jié)果JSON應(yīng)該像{  "userId" :2,  "userName" : "john",  "emailId" : "john@gmail.com"}我不想發(fā)送給其他數(shù)據(jù)庫表的客戶端的字段列表。因此，它將根據(jù)登錄的用戶進行更改。我該怎么做？