How get web URL from RTC work item in RTC server follow-up action plugin?

Hello!
I have implemented such code to get work item references in an RTC server side plug-in (follow-up action):

        IWorkItemReferences refs = saveParameter.getNewReferences();
        List<IEndPointDescriptor> listRefTypes = refs.getTypes();
        for (IEndPointDescriptor refType : listRefTypes) {
             List<IReference> listReferences = refs.getReferences(refType);
            for (IReference ref : listReferences) {
                URI link_uri = ref.createURI();
                URL link_url = link_uri.toURL();
                ...
            }

Of course, here I have an IllegalArgumentException because of link_uri which is really looking like to "itemOid/com.ibm.team.workitem.WorkItem/_1bF4ILBAEeO-gIIGxPDnjA". But nevertheless, I can see the normal URL for the link in RTC GUI (both in RTC Eclipse and Web UI):

https://localhost:7443/jazz/resource/itemName/com.ibm.team.workitem.WorkItem/4

I even can not simply add "http://", server name and port because URI is different from URL conventions! Can somebody help how can it be got a standard URL link in Web format including current server, port, linked object and so on?
Thank you!