UserDetailsService returned null, which is an interface contract violation

Oi!

Só acontece esse erro quando não encontra o usuário/senha na tabela de usuários do bnanco de dados. Confere na tabela se tem esse login/senha que você está enviando no json.

Sim... Estou com erro no Banco de Dados, o Spring não está reconhecendo os dados armazenados.

Error starting Tomcat context. Exception: org.springframework.beans.factory.UnsatisfiedDependencyException. Message: Error creating bean with name 'securityFilter': Unsatisfied dependency expressed through field 'repository': Error creating bean with name 'userRepository' defined in med.voll.api.domain.user.UserRepository defined in @EnableJpaRepositories declared on PersistenceJPAConfig: Cannot resolve reference to bean 'jpaSharedEM_entityManagerFactory' while setting bean property 'entityManager'

package med.voll.api.infra.security;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.HttpMethod;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.config.annotation.authentication.configuration.AuthenticationConfiguration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.http.SessionCreationPolicy;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.security.web.SecurityFilterChain;
import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;

@Configuration
@EnableWebSecurity
public class SecurityConfigurations {

    @Autowired
    private SecurityFilter securityFilter;
    @Bean
    public SecurityFilterChain securityFilterChain(HttpSecurity http) throws Exception {
        return http.csrf(csrf -> csrf.disable())
                .sessionManagement(sm -> sm.sessionCreationPolicy(SessionCreationPolicy.STATELESS))
                .authorizeHttpRequests(req -> {
                    req.requestMatchers(HttpMethod.POST, "/login").permitAll();
                    req.anyRequest().authenticated();
                })
                .addFilterBefore(new UsernamePasswordAuthenticationFilter(), UsernamePasswordAuthenticationFilter.class)
                .build();
    }

    @Bean
    public AuthenticationManager authenticationManager(AuthenticationConfiguration configuration) throws Exception {
        return configuration.getAuthenticationManager();
    }

    @Bean
    public PasswordEncoder passwordEncoder() {
        return new BCryptPasswordEncoder();
    }
}

package med.voll.api.domain.user;

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.stereotype.Repository;

@Repository
public interface UserRepository extends JpaRepository <User, Long> {
    UserDetails findByLogin(String login);
}

Manda aqui tua classe User e faz um select na tabela de usuarios do banco de dados e manda um print aqui

import jakarta.persistence.*;
import lombok.*;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.core.userdetails.UserDetails;


import java.util.Collection;
import java.util.List;


@Table(name = "usuarios")
@Entity
@NoArgsConstructor
@Data
public class User implements UserDetails {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String login;
    private String senha;


    public User(String login, String senha){
        this.login = login;
        this.senha = senha;
    }

    @Override
    public Collection<? extends GrantedAuthority> getAuthorities() {
        return List.of(new SimpleGrantedAuthority("ROLE_USER"));
    }

    @Override
    public String getPassword() {
        return senha;
    }

    @Override
    public String getUsername() {
        return login;
    }

    @Override
    public boolean isAccountNonExpired() {
        return true;
    }

    @Override
    public boolean isAccountNonLocked() {
        return true;
    }

    @Override
    public boolean isCredentialsNonExpired() {
        return true;
    }

    @Override
    public boolean isEnabled() {
        return true;
    }
}

Está tudo certo.

Coloca um system.out no AutenticacaoService, para ver se está chegando o login certinho de acordo com o json enviado:

@Service
public class AutenticacaoService implements UserDetailsService {

    @Autowired
    private UsuarioRepository repository;

    @Override
    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
        System.out.println("LOGIN RECEBIDO: " +username);
        return repository.findByLogin(username);
    }
}

Inseri uma nova migration contendo o usuário e senha, e funcionou!