Why SecurityContextHolder.getContext() == null? - spring

Question

I don't run my app, because auth == null. Why? I use spring boot 2.2.7.RELEASE and spring-security-oauth2-autoconfigure.
When starting SecurityContextHolder.getContext() always equal null
#Component
#Configuration
#EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
#Autowired
DataSource dataSource;
#Autowired
UserRepository userRepository;
#Autowired
PasswordEncoder passwordEncoder;
#Bean
public PasswordEncoder encoder() {
return new BCryptPasswordEncoder();
}
Authentication auth = SecurityContextHolder.getContext().getAuthentication();
#Override
protected void configure(HttpSecurity http) throws Exception {
http.authorizeRequests()
.antMatchers("/addPet").authenticated()
.antMatchers("/", "/**").access("permitAll")
.and().oauth2Login().loginPage("/login").defaultSuccessUrl("/", true).and().logout().logoutSuccessUrl("/")
.and().formLogin().loginPage("/login").loginProcessingUrl("/login").usernameParameter("login").passwordParameter("password")
.defaultSuccessUrl("/", true).and().logout().logoutSuccessUrl("/").deleteCookies("JSESSIONID").and().csrf().disable();
}
#Autowired
public void configAuthentication(AuthenticationManagerBuilder auth) throws Exception {
auth.jdbcAuthentication().dataSource(dataSource)
.usersByUsernameQuery(
"select login, password, enabled from users where login=?")
.authoritiesByUsernameQuery(
"select login, role from users where login=?");
}
}

Answer 1

I assume that you're referring to this line,
Authentication auth = SecurityContextHolder.getContext().getAuthentication();
In this case, you don't need this line, it's not being used anywhere. In the bigger answer, SecurityContextHolder.getContext() will never be null, according to the documentation. The call to getAuthentication(), however, will be null unless there's an authenticated principal associated to the session.