[SOLVED] Spring boot security consider case insensitive username check for login

I'm developing a Spring boot web application. The problem is in the login scenario. Suppose I have a user registered by the username "Ali". This user can either login with username "Ali" or "ali". The code below represents my spring security config class. It seems while comparing, Spring boot does not check the uppercase lowercase factor, but I want it to be checked.

package nf.something.conf;

import nf.something.repo.EventRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.web.servlet.ServletListenerRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.HttpMethod;
import org.springframework.security.authentication.AuthenticationProvider;
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.core.session.SessionRegistry;
import org.springframework.security.core.session.SessionRegistryImpl;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.web.AuthenticationEntryPoint;
import org.springframework.security.web.authentication.AuthenticationFailureHandler;
import org.springframework.security.web.authentication.AuthenticationSuccessHandler;
import org.springframework.security.web.authentication.SimpleUrlAuthenticationFailureHandler;
import org.springframework.security.web.authentication.logout.LogoutSuccessHandler;
import org.springframework.security.web.header.writers.StaticHeadersWriter;
import org.springframework.security.web.session.HttpSessionEventPublisher;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

import javax.sql.DataSource;

/**
 * Created by reza on 11/12/16.
 */
@Configuration
public class SecurityConf extends WebSecurityConfigurerAdapter {

    @Autowired
    private DataSource datasource;
    @Autowired
    private EventRepository eventRepository;

    // Register HttpSessionEventPublisher
    @Bean
    public static ServletListenerRegistrationBean httpSessionEventPublisher() {
        return new ServletListenerRegistrationBean(new HttpSessionEventPublisher());
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests()
//                 .antMatchers(HttpMethod.POST, "/users/").permitAll()
                .antMatchers(HttpMethod.GET, "/**").permitAll()
                .antMatchers(HttpMethod.POST, "/**").permitAll()
                .antMatchers(HttpMethod.PUT, "/**").permitAll()
                .antMatchers(HttpMethod.DELETE, "/**").permitAll()
                .antMatchers("/swagger*").permitAll()
                //.anyRequest().permitAll()
                //.and().csrf().disable();
                .anyRequest().authenticated()
                .and().httpBasic()
                .and().formLogin().successHandler(restAuthenticationSuccessHandler()).failureHandler(restAuthenticationFailureHandler())
                .and().logout().logoutSuccessHandler(restLogoutSuccessHandler())
                .and().exceptionHandling().authenticationEntryPoint(restAuthenticationEntryPoint())
                .and().csrf().disable().cors() //TODO enable csrf when we are ready
                .and().sessionManagement().maximumSessions(1).maxSessionsPreventsLogin(true).sessionRegistry(sessionRegistry());
        http.headers().cacheControl().disable()
                .addHeaderWriter(new StaticHeadersWriter("WWW-Authenticate","xBasic realm=\"fake\""));
    }

    @Bean
    public SessionRegistry sessionRegistry() {
        SessionRegistry sessionRegistry = new SessionRegistryImpl();
        return sessionRegistry;
    }

    @Bean
    public WebMvcConfigurer corsConfigurer() {
        return new WebMvcConfigurerAdapter() {
            @Override
            public void addCorsMappings(CorsRegistry registry) {
                registry.addMapping("/**").allowedOrigins("*").allowedMethods("PUT", "POST", "GET", "DELETE", "HEAD");
            }
        };
    }

    @SuppressWarnings("SpringJavaAutowiringInspection")
    @Autowired
    public void configureGlobal(AuthenticationManagerBuilder auth, UserDetailsService userDetailsService) throws Exception {
        /*auth
                .jdbcAuthentication().usersByUsernameQuery("Select username,password, 'true' as enabled from Users where username=?")
                .authoritiesByUsernameQuery("select username, authority from authorities where username=?")
                .dataSource(datasource).passwordEncoder(new BCryptPasswordEncoder());*/
        auth.userDetailsService(userDetailsService)
                .passwordEncoder(new BCryptPasswordEncoder());
    }

    @Bean
    public AuthenticationEntryPoint restAuthenticationEntryPoint() {
        return new RestAuthenticationEntryPoint();
    }

    @Bean
    public AuthenticationFailureHandler restAuthenticationFailureHandler() {
        return new SimpleUrlAuthenticationFailureHandler();
    }

    @Bean
    public AuthenticationSuccessHandler restAuthenticationSuccessHandler() {
        return new RESTAuthenticationSuccessHandler(eventRepository);
    }

    @Bean
    public LogoutSuccessHandler restLogoutSuccessHandler() {
        return new RESTLogoutSuccessHandler(eventRepository);
    }
}

I have also implemented equals method in User class:

@Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (!(o instanceof User)) return false;

        User user = (User) o;
     
        if (!getUsername().equals(user.getUsername())) return false;
        if (getName() != null ? !getName().equals(user.getName()) : user.getName() != null) return false;
        if (getFamily() != null ? !getFamily().equals(user.getFamily()) : user.getFamily() != null) return false;
        if (getPassword() != null ? !getPassword().equals(user.getPassword()) : user.getPassword() != null)
            return false;
        return getMobilePhone() != null ? getMobilePhone().equals(user.getMobilePhone()) : user.getMobilePhone() == null;
    }