如何在Springboot中获取LDAP用户名

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-security</artifactId>
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-ldap</artifactId>
</dependency>

spring.ldap.urls=ldap://ldap.example.com:389
spring.ldap.base=dc=example,dc=com
spring.ldap.username=cn=admin,dc=example,dc=com
spring.ldap.password=adminpassword

@Configuration
@EnableWebSecurity
public class LdapSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth
            .ldapAuthentication()
                .userSearchBase("ou=users")
                .userSearchFilter("(uid={0})")
                .groupSearchBase("ou=groups")
                .groupSearchFilter("member={0}")
                .contextSource()
                    .url("ldap://ldap.example.com:389/dc=example,dc=com")
                    .managerDn("cn=admin,dc=example,dc=com")
                    .managerPassword("adminpassword");
    }
}

@RestController
public class UserController {

    @GetMapping("/username")
    public String getUsername(Authentication authentication) {
        return authentication.getName();
    }
}