Vaadin BeanCreationException: during trying to call save method of my service class - spring-boot

Question

Hi I have a little Vaadin project. In there, I've a UserUtils.class which has a createNewUser method which looks like this:
LoginView:
import com.vaadin.flow.component.html.H1;
import com.vaadin.flow.component.login.LoginForm;
import com.vaadin.flow.component.orderedlayout.VerticalLayout;
import com.vaadin.flow.router.BeforeEnterEvent;
import com.vaadin.flow.router.BeforeEnterObserver;
import com.vaadin.flow.router.PageTitle;
import com.vaadin.flow.router.Route;
import org.springframework.security.crypto.password.PasswordEncoder;
import java.util.Collections;
import static com.packagename.utils.UserUtils.createNewUser;
#Route("login")
#PageTitle("Login - packagename")
public class LoginView extends VerticalLayout implements BeforeEnterObserver {
private LoginForm login = new LoginForm();
private PasswordEncoder passwordEncoder;
public LoginView(){
createNewUser("daniel.tran", "cAWFCMaa22", true, "ADMIN");
addClassName("login-view");
setSizeFull();
setAlignItems(Alignment.CENTER);
setJustifyContentMode(JustifyContentMode.CENTER);
login.setAction("login");
add(
new H1("Willkommen!"),
login
);
}
#Override
public void beforeEnter(BeforeEnterEvent event) {
// Inform the user about an authentication error
if (!event.getLocation()
.getQueryParameters()
.getParameters()
.getOrDefault("error", Collections.emptyList())
.isEmpty()) {
login.setError(true);
}
}
}
UserUtils.class:
import com.packagename.backend.entity.UserEntity;
import com.packagename.backend.service.UserService;
import com.packagename.security.SecurityConfiguration;
import com.packagename.ui.views.login.LoginView;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.crypto.password.PasswordEncoder;
public class UserUtils {
#Autowired
private LoginView loginView;
private static UserService userService;
private PasswordEncoder passwordEncoder;
public static void createNewUser(String pUsername, String pPassword, boolean pStatus, String pRole) {
if (!UserUtils.userExists(pUsername)) {
userService = new UserService();
PasswordEncoder passwordEncoder = SecurityConfiguration.passwordEncoder();
String encodedPassword = passwordEncoder.encode(pPassword);
UserEntity user = new UserEntity();
user.setUserName(pUsername);
user.setPassword(encodedPassword);
user.setStatus(pStatus);
user.setRoles(pRole);
userService.save(user);
}
}
private static boolean userExists(String pUsername) {
userService = new UserService();
UserEntity user = new UserEntity();
user.setUserName(pUsername);
boolean exists = userService.exists(user);
return exists;
}
}
UserService.class:
import com.packagename.backend.entity.UserEntity;
import com.packagename.backend.repository.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Example;
import org.springframework.stereotype.Service;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
#Service
public class UserService {
private UserRepository userRepository;
private Logger LOGGER;
#Autowired
public UserService(UserRepository pUserRepository) {
this.userRepository = pUserRepository;
}
public UserService() {}
public List<UserEntity> findAll() {
return userRepository.findAll();
}
public long count() {
return userRepository.count();
}
public void delete(UserEntity user) {
userRepository.delete(user);
}
public void save(UserEntity user) {
if (user == null) {
LOGGER.log(Level.SEVERE, "Contact is null. Are you sure you have connected your form to the application?");
return;
}
userRepository.save(user);
}
public boolean exists(UserEntity user) {
Example<UserEntity> example = Example.of(user);
boolean exists = userRepository.exists(example);
return exists;
}
}
UserEntity.class:
import javax.persistence.*;
#Entity
#Table(name = "PSYS_USERS")
public class UserEntity {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private int userid;
private String userName;
private String password;
private boolean status;
private String roles;
public UserEntity(){}
public int getUserid() {
return userid;
}
public void setUserid(int userid) {
this.userid = userid;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public boolean isStatus() {
return status;
}
public void setStatus(boolean status) {
this.status = status;
}
public String getRoles() {
return roles;
}
public void setRoles(String roles) {
this.roles = roles;
}
}
UserRepository.class
import com.packagename.backend.entity.UserEntity;
import org.springframework.data.jpa.repository.JpaRepository;
import java.util.Optional;
public interface UserRepository extends JpaRepository<UserEntity, Integer> {
Optional<UserEntity> findByUserName(String userName);
}
And always when it comes to the situtation, trying to call the userService methods, then it throws the following exception:
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.packagename.ui.views.login.LoginView': Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.packagename.ui.views.login.LoginView]: Constructor threw exception; nested exception is java.lang.NullPointerException
I tried to create a default constructor, at the entity and also at the service class but nothing want help.
So far,
Daniel

Answer 1

new UserService(); - this is the problem.
you cannot instantiate spring components on your own, you have to let spring inject/autowire them.
Places where you can inject Spring components are spring components themselves, and with Vaadin, you can inject in your views that have a #Route annotation. LoginView is such a view. So there you inject the UserService, and pass it along to the createNewUser method.
// LoginView constructor
// userService is injected/autowired this way
public LoginView(UserService userService){
createNewUser("daniel.tran", "cAWFCMaa22", true, "ADMIN", userService);
addClassName("login-view");
setSizeFull();
setAlignItems(Alignment.CENTER);
setJustifyContentMode(JustifyContentMode.CENTER);
login.setAction("login");
add(
new H1("Willkommen!"),
login
);
}
// UserUtils
public static void createNewUser(String pUsername, String pPassword, boolean pStatus, String pRole, UserService userService) {
if (!UserUtils.userExists(pUsername, userService)) {
PasswordEncoder passwordEncoder = SecurityConfiguration.passwordEncoder();
String encodedPassword = passwordEncoder.encode(pPassword);
UserEntity user = new UserEntity();
user.setUserName(pUsername);
user.setPassword(encodedPassword);
user.setStatus(pStatus);
user.setRoles(pRole);
userService.save(user);
}
}
private static boolean userExists(String pUsername, UserService userService) {
UserEntity user = new UserEntity();
user.setUserName(pUsername);
boolean exists = userService.exists(user);
return exists;
}
By the way, UserUtils is not a Spring Component so you cant autowire the loginView there either - good thing it's not used anyway