LdapDnsProvider (Java SE 12 & JDK 12 )

java.lang.Object
- javax.naming.ldap.spi.LdapDnsProvider

```
public abstract class LdapDnsProvider
extends Object
```
Service-provider class for DNS lookups when performing LDAP operations.
An LDAP DNS provider is a concrete subclass of this class that has a zero-argument constructor. LDAP DNS providers are located using the ServiceLoader facility, as specified by InitialDirectContext. The ServiceLoader is used to create and register implementations of LdapDnsProvider.
An LDAP DNS provider can be used in environments where the default DNS resolution mechanism is not sufficient to accurately pinpoint the correct LDAP servers needed to perform LDAP operations. For example, in an environment containing a mix of ldap and ldaps servers you may want the LdapContext to query ldaps servers only.

Since:

12

Constructor Summary

Constructors
Modifier Constructor Description

protected LdapDnsProvider()
Creates a new instance of LdapDnsProvider.

Method Summary

Modifier and Type	Method	Description
`abstract Optional<LdapDnsProviderResult>`	`lookupEndpoints(String url, Map<?,?> env)`	Lookup the endpoints and domain name for the given `Context` `provider URL` and environment.

Methods declared in class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - LdapDnsProvider
```
protected LdapDnsProvider()
```
    Creates a new instance of LdapDnsProvider.
    
    Throws:
    
    SecurityException - if a security manager is present and its checkPermission method doesn't allow the RuntimePermission("ldapDnsProvider").
- Method Detail
  - lookupEndpoints
```
public abstract Optional<LdapDnsProviderResult> lookupEndpoints(String url,
                                                                Map<?,?> env)
                                                         throws NamingException
```
    Lookup the endpoints and domain name for the given Context provider URL and environment. The resolved endpoints and domain name are returned as an LdapDnsProviderResult.
    An endpoint is a String representation of an LDAP URL which points to an LDAP server to be used for LDAP operations. The syntax of an LDAP URL is defined by RFC 2255: The LDAP URL Format.
    
    Parameters:
    
    url - The Context provider URL
    
    env - The Context environment.
    
    Returns:
    
    an LdapDnsProviderResult or empty Optional if the lookup fails.
    
    Throws:
    
    NamingException - if the url is not valid or an error occurred while performing the lookup.
    
    NullPointerException - if either url or env are null.