ldap/src/main/java/org/springframework/security/ldap/DefaultLdapUsernameToDnMapper.java
public DistinguishedName buildDn(String username) {
		DistinguishedName dn = new DistinguishedName(userDnBase);

		dn.add(usernameAttribute, username);

		return dn;
	}
public DistinguishedName buildDn(String username) {
		DistinguishedName dn = new DistinguishedName(userDnBase);

		dn.add(usernameAttribute, username);

		return dn;
	}
Assembles the Distinguished Name that should be used the given username.