How to simulate an url provider

Hello everybody,
I'm new user.
I'm trying to test my program witch get an url provider into my server (websphere):
//-----------------------------------------------------------------------------
private static final String REF_URL_SIGNEL ="url/myUrl";

JndiObjectFactoryBean jndiBean = new JndiObjectFactoryBean();

JndiTemplate jndiTemplate = new JndiTemplate();

jndiBean.setJndiTemplate(jndiTemplate);

URL url = null;

try {

InitialContext ic = new InitialContext();
url = (URL)jndiTemplate.lookup(REF_URL_SIGNEL);

} catch (NamingException e) {

LOG.error("error JNDI["+e+"]");

}
//-----------------------------------------------------------------------------

I wanted to how if it's possible to set my url/myUrl --> http://toto into the beginning of my junit test.
thank for your help.