validate against AD with Spring

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.authentication.AuthenticationProvider;
import org.springframework.security.authentication.ProviderManager;
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.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.ldap.authentication.ad.ActiveDirectoryLdapAuthenticationProvider;

import java.util.Collections;

@Configuration
@EnableWebSecurity
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    private UserDetailsContextMapperImpl userDetailsContextMapper;

    @Value("${ldap.disable:false}")
    private String disable;

    @Value("${ldap.domain}")
    private String domain;

    @Value("${ldap.url}")
    private String url;

    @Override
    protected void configure(final HttpSecurity http) throws Exception {

        if (!"true".equals(disable)) {
            http
                    .formLogin()
                    .permitAll()
                    .and()
                    .authorizeRequests()
                    .antMatchers("/ErrorViewer/*")
                    .authenticated()
                    .and().csrf().disable();
        } else {
            http.csrf().disable();
        }
    }

    @Override
    protected void configure(final AuthenticationManagerBuilder authManagerBuilder) throws Exception {
        authManagerBuilder.authenticationProvider(activeDirectoryLdapAuthenticationProvider()).userDetailsService(userDetailsService());
    }

    @Bean
    public AuthenticationManager authenticationManager() {
        return new ProviderManager(Collections.singletonList(activeDirectoryLdapAuthenticationProvider()));
    }

    @Bean
    public AuthenticationProvider activeDirectoryLdapAuthenticationProvider() {
        final ActiveDirectoryLdapAuthenticationProvider provider = new ActiveDirectoryLdapAuthenticationProvider(domain, url);
        provider.setConvertSubErrorCodesToExceptions(true);
        provider.setUseAuthenticationRequestCredentials(true);
        provider.setUserDetailsContextMapper(userDetailsContextMapper);
        return provider;
    }
}