does this ldap code work?

Hi,

I dont have an ldap server, tested this at work without success - but I
may in the wrong server something - can you tell me if this code alone
is enough to purely authenticate against an LDAP server? Do I need
other key properties - I tried port 389 without success - I get a timed
out error.

import javax.naming.Context;
import javax.naming.NamingException;
import javax.naming.directory.*;

public class LdapAuthentication {

    private String initialContext = "com.sun.jndi.ldap.LdapCtxFactory";
    private String authenticationMethod = "simple";
    private String providerUrl = "ldap://ldap:636";

    public LdapAuthentication() {
        super();
    }

    public void authenticate (String username, String password) throws
InvalidUserLoginException {
        DirContext ctx = null;
        try {
            ctx = getContext(username, password);
        } catch (NamingException ne) {
            throw new InvalidUserLoginException(ne.toString());
        } finally {
            if (ctx != null) {
                try {
                    ctx.close();
                } catch (NamingException ne) {
                }
            }
        }
    }

    protected DirContext getContext(String username, String password)
throws NamingException {
        Hashtable env = new Hashtable();

        env.put(Context.INITIAL_CONTEXT_FACTORY, initialContext);
        env.put(Context.PROVIDER_URL, providerUrl);
        env.put(Context.SECURITY_AUTHENTICATION,authenticationMethod);
        env.put(Context.SECURITY_PRINCIPAL, username);
        env.put(Context.SECURITY_CREDENTIALS, password);

        DirContext ctx = new InitialDirContext(env);
        return ctx;

    }
}