如何使用spring-ldap从ldap读取值

<dependency>
    <groupId>org.springframework.ldap</groupId>
    <artifactId>spring-ldap-core</artifactId>
    <version>2.3.4.RELEASE</version>
</dependency>

<ldap:context-source
    url="ldap://ldap.example.com:389"
    base="dc=example,dc=com"
    username="cn=admin,dc=example,dc=com"
    password="adminPassword" />

@Autowired
private LdapTemplate ldapTemplate;

public String readAttributeValue(String dn, String attributeName) {
    return ldapTemplate.lookup(dn, (Attributes attributes) -> {
        Attribute attribute = attributes.get(attributeName);
        if (attribute != null) {
            return attribute.get().toString();
        }
        return null;
    });
}

String dn = "uid=john.doe,ou=users,dc=example,dc=com";
String attributeName = "cn";
String attributeValue = readAttributeValue(dn, attributeName);
System.out.println(attributeValue);