Spring tool suite: not-null property references a null or transient value - spring

Question

could you help me with this question?
I built a project on sts4. I am trying to let users register an account on Postman. The primary method I am testing is Put(PutMapping), which I wrote on sts4. I got the project initialized completely, but when I click send from Postman, I got errors like below.
not-null property references a null or transient value: com.appsdeveloperblog.app.ws.io.entity.UserEntity.firstName
The following is part of my project.
UserDetailsRequestModel, (for processing incoming requestbody)
public class UserDetailsRequestModel {
private String firstName;
private String lastName;
private String email;
private String password;
public String getFirstname() {
return firstName;
}
public void setFirstname(String firstname) {
this.firstName = firstname;
}
public String getLastname() {
return lastName;
}
public void setLastname(String lastname) {
this.lastName = lastname;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}```
2. UserRest, (Class, which will be returned back to Postman)
```package com.appsdeveloperblog.app.ws.ui.model.response;
public class UserRest {
// public id, not auto increment key from database
private String userId;
private String firstName;
private String lastName;
private String email;
public String getUserId() {
return userId;
}
public void setUserId(String userId) {
this.userId = userId;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
}```
3. UserDTO
```package com.appsdeveloperblog.app.ws.shared.dto;
import java.io.Serializable;
public class UserDTO implements Serializable {
private static final long serialVersionUID = -5607842248454975055L;
// auto increment key from database
private long id;
// public user id, which could be returned back to application
private String userId;
private String firstName;
private String lastName;
private String email;
// clear text password
private String password;
// password which is encrypted, stored,
private String encryptedPassword;
private String emailVerificationToken;
private Boolean emailVerificationStatus = false;
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getUserId() {
return userId;
}
public void setUserId(String userId) {
this.userId = userId;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getEncryptedPassword() {
return encryptedPassword;
}
public void setEncryptedPassword(String encryptedPassword) {
this.encryptedPassword = encryptedPassword;
}
public String getEmailVerificationToken() {
return emailVerificationToken;
}
public void setEmailVerificationToken(String emailVerificationToken) {
this.emailVerificationToken = emailVerificationToken;
}
public Boolean getEmailVerificationStatus() {
return emailVerificationStatus;
}
public void setEmailVerificationStatus(Boolean emailVerificationStatus) {
this.emailVerificationStatus = emailVerificationStatus;
}
}
UserEntity
import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
#Entity(name = "users")
public class UserEntity implements Serializable {
private static final long serialVersionUID = 5313493413859894403L;
// this Id is a primary key and auto incremented
// once a new record is inserted into database table
#Id
#GeneratedValue
private long id;
#Column(nullable = false)
private String userId;
#Column(nullable = false, length = 50)
private String firstName;
#Column(nullable = false, length = 50)
private String lastName;
#Column(nullable = false, length = 120)
private String email;
#Column(nullable = false)
private String encryptedPassword;
private String emailVerificationToken;
#Column(nullable = false)
private Boolean emailVerificationStatus = false;
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getUserId() {
return userId;
}
public void setUserId(String userId) {
this.userId = userId;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getEncryptedPassword() {
return encryptedPassword;
}
public void setEncryptedPassword(String encryptedPassword) {
this.encryptedPassword = encryptedPassword;
}
public String getEmailVerificationToken() {
return emailVerificationToken;
}
public void setEmailVerificationToken(String emailVerificationToken) {
this.emailVerificationToken = emailVerificationToken;
}
public Boolean getEmailVerificationStatus() {
return emailVerificationStatus;
}
public void setEmailVerificationStatus(Boolean emailVerificationStatus) {
this.emailVerificationStatus = emailVerificationStatus;
}
}
UserServiceImpl
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.appsdeveloperblog.app.ws.UserRepository;
import com.appsdeveloperblog.app.ws.io.entity.UserEntity;
import com.appsdeveloperblog.app.ws.service.UserService;
import com.appsdeveloperblog.app.ws.shared.dto.UserDTO;
#Service
public class UserServiceImpl implements UserService {
#Autowired
UserRepository userRepository;
#Override
public UserDTO createUser(UserDTO user) {
// (0) check whether the email already exist in database
if(userRepository.findByEmail(user.getEmail()) != null) {
throw new IllegalArgumentException("Email already exists.");
}
// 1. create an object UserEntity,
UserEntity userEntity = new UserEntity();
// 2. copy info from userDTO to userEntity
BeanUtils.copyProperties(user, userEntity);
// 3. encryptedPassword can't be got from user
// we have to assign value here for testing
userEntity.setEncryptedPassword("test");
// 4. the second data that is generated during this class is userID
userEntity.setUserId("testUserId");
// 5. now we can save userEntity into database,
// since it contains info from user, have to use userRepository
// after Auto-wired, we can use its methods
// use save method, we can save userEntity into database
UserEntity storedUserDetails = userRepository.save(userEntity);
// 6. we can return it back to RestController
// so we need an UserDTO object
UserDTO returnValue = new UserDTO();
BeanUtils.copyProperties(storedUserDetails, returnValue);
return returnValue;
}
}
UserController
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.PutMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import com.appsdeveloperblog.app.ws.service.UserService;
import com.appsdeveloperblog.app.ws.shared.dto.UserDTO;
import com.appsdeveloperblog.app.ws.ui.model.request.UserDetailsRequestModel;
import com.appsdeveloperblog.app.ws.ui.model.response.UserRest;
#RestController // to make this class receive requests from HTTP
#RequestMapping("users") // http://localhost:8080/users + methods
public class UserController {
#Autowired
UserService userService;
#GetMapping
public String getUser() {
return "get user was called";
}
#PostMapping
public UserRest createUser(#RequestBody UserDetailsRequestModel userDetails) {
// 1. instantiate a new object, which will be returned.
UserRest returnValue = new UserRest();
System.out.println(userDetails.getFirstname());
// 2. instantiate a new User Data transfer object,
// which could be shared across different layers
// we will populate this object with info we received from request body
UserDTO userDTO = new UserDTO();
// 3. use class BeanUtils class, which is from spring framework
// to copy properties from source object(userDetails) to our data transfer object
// so, we can populate info from request body into our data transfer object
// so, we have a data transfer object, which is populated info from request body
BeanUtils.copyProperties(userDetails, userDTO);
// 4.
// (1) userDTO, will be created at UI level, then be passed to service layer
// (2) service class will perform some additional business logic
// and generate some additional values, these values will be added to userDTO,
// (3) then userDTO will be used in business logic with a data layer
// to prepare an entity class, which will be stored in database
UserDTO createdUser = userService.createUser(userDTO);
// 5. populate returnValue object
// copy information from createdUser into returnValue
// other sensitive info, like password, should not be included
BeanUtils.copyProperties(createdUser, returnValue);
// 6. return, to mobile applications，or in here to Postman(HTTP client)
return returnValue;
}
#PutMapping
public String updateUser() {
return "update user was called";
}
#DeleteMapping
public String deleteUser() {
return "delete user was called";
}
}
Configuration on Postman
enter image description here
enter image description here
The Error I got
enter image description here
I spent a day on it. Help, please.

Answer 1

Try this:
#PutMapping
public String updateUser(#RequestBody) {
return "update user was called";
}