The Java Naming and Directory Interface (JNDI) is the standard Java API for multiple naming and directory services such as Lightweight Directory Access Protocol (LDAP).

Active Directory is a group of network services like account authentication and it supports LDAP. Therefore, you can write a Java program using JNDI in order to obtain the account credentials in the Active Directory of a Windows Server. Here comes the example.

I have already setup Windows Server with Active Directory and created my account there.

                                

The following Java program could connect to the above Windows Server through LDAP. Please note that you have to use the User logon name (username@domain) for Context.SECURITY_PRINCIPAL.
LdapContextCreation.java

import java.util.Hashtable;
import javax.naming.Context;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.directory.Attribute;
import javax.naming.directory.Attributes;
import javax.naming.ldap.InitialLdapContext;
import javax.naming.ldap.LdapContext;

public class LdapContextCreation {

	public static void main(String[] args) {
		try {
			// Create a LDAP Context
			Hashtable env = new Hashtable();  
			env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory");  
			env.put(Context.SECURITY_AUTHENTICATION, "simple");  
			env.put(Context.SECURITY_PRINCIPAL, "ykyuen@cecid03server.hku.hk");  
			env.put(Context.SECURITY_CREDENTIALS, "your password here");  
			env.put(Context.PROVIDER_URL, "ldap://cecid-03server:389");
			LdapContext ctx = new InitialLdapContext(env, null);  
			System.out.println("Connection Successful.");

			// Print all attributes of the name in namespace
			Attributes attributes = null;
			attributes = ctx.getAttributes(ctx.getNameInNamespace());
			for (NamingEnumeration ae = attributes.getAll(); ae.hasMoreElements();) {
				Attribute attr = (Attribute)ae.next();
				String attrId = attr.getID();
				for (NamingEnumeration vals = attr.getAll(); vals.hasMore();) {
					String thing = vals.next().toString();
					System.out.println(attrId + ": " + thing);
				}
			}
			ctx.close();
		} catch (NamingException e) {
			System.out.println("LDAP Connection: FAILED");  
			e.printStackTrace();  
		}
	}
}

Done =)

Reference: Active Directory Access Authentication using LDAP and Java