The setLocators method in the AssociationDescriptor class is documented as follows:

 /**
     * This method provids the ability to set the array of locators that this
     * ServiceBean would like to join. If this parameter is not set (remains
     * null), then attempts will be made via unicast discovery
     *
     * @param lookupLocators Array of LookupLocator instances
     */
    public void setLocators(LookupLocator... lookupLocators)

if the array of LookupLocators remains null, unicast is used? Should that say multicast is used?

The javadoc should state:

If this parameter is not set, then no attempts will be made via unicast discovery