net.sf.michaelo.activedirectory

Class ActiveDirectoryDnsLocator

java.lang.Object

net.sf.michaelo.activedirectory.ActiveDirectoryDnsLocator

public class ActiveDirectoryDnsLocator
extends Object

A locator for various Active Directory services like LDAP, Global Catalog, Kerberos, etc. via DNS SRV resource records. This is a lightweight implementation of RFC 2782 for the resource records depicted here, but with the limitation that only TCP is queried and the _msdcs subdomain is ignored. The server selection algorithm for failover is fully implemented.

Here is a minimal example how to create a ActiveDirectoryDnsLocator with the supplied builder:

 ActiveDirectoryDnsLocator.Builder builder = new ActiveDirectoryDnsLocator.Builder();
 ActiveDirectoryDnsLocator locator = builder.build();
 HostPort[] servers = locator.locate("ldap", "ad.example.com");
 

An ActiveDirectoryDnsLocator object will be initially preconfigured by its builder for you:

1. The context factory is set by default to com.sun.jndi.dns.DnsContextFactory.

A complete overview of all DirContext properties can be found here. Make sure that you pass reasonable/valid values only otherwise the behavior is undefined.

Note: This class uses JULI to print log messages, enable at least level FINE to see output.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ActiveDirectoryDnsLocator.Builder A builder to construct an ActiveDirectoryDnsLocator with a fluent interface.
static class	ActiveDirectoryDnsLocator.HostPort A mere container for a host along with a port.

Method Summary

Modifier and Type	Method and Description
ActiveDirectoryDnsLocator.HostPort[]	locate(String service, String domainName) Locates a desired service via DNS within an Active Directory domain, sorted and selected according to RFC 2782.
ActiveDirectoryDnsLocator.HostPort[]	locate(String service, String site, String domainName) Locates a desired service via DNS within an Active Directory site and domain, sorted and selected according to RFC 2782.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

locate

public ActiveDirectoryDnsLocator.HostPort[] locate(String service,
                                                   String site,
                                                   String domainName)
                                            throws NamingException

Locates a desired service via DNS within an Active Directory site and domain, sorted and selected according to RFC 2782.

Parameters:

service - the service to be located

site - the Active Directory site the client resides in

domainName - the desired domain name. Can be any naming context name.

Returns:

the located servers or null if none found

Throws:

NullPointerException - if service or domain name is null

IllegalArgumentException - if service or domain name is empty

NamingException - if an error has occurred while creating or querying the DNS directory context

IllegalStateException - if any of the DNS returned RRs not adhere to the RFC

locate

public ActiveDirectoryDnsLocator.HostPort[] locate(String service,
                                                   String domainName)
                                            throws NamingException

Locates a desired service via DNS within an Active Directory domain, sorted and selected according to RFC 2782.

Parameters:

service - the service to be located

domainName - the desired domain name. Can be any naming context name.

Returns:

the located servers or null if none found

Throws:

NullPointerException - if service or domain name is null

IllegalArgumentException - if service or domain name is empty

NamingException - if an error has occurred while creating or querying the DNS directory context

IllegalStateException - if any of the DNS returned RRs not adhere to the RFC