According to the API Docs (https://developers.podio.com/doc/items/get-item-22360)
GET /item/{item_id}
Returns a ton of useful information. This information includes things like:
"link": The full link to the item
and
"item_name": The name of an item in the app,
However, when you use ItemAPI.getItem(int itemID), you get back an Item which does not carry this information.
In fact, after some (but not much) digging, it seems the Item-related class that has this info is ItemBadge, which comes from an ItemsResponse after something like itemAPI.getItems(appID...)
So, if you actually have the itemID, and then you pull the full item down via the API through the Java Library, there seems to be no easy way to get a direct link or even the internal id of that item which could be used to build a link.
ItemMicros (which come from following references) don't seem to have this info either.
Clearly the API is returning this info, so perhaps we could get access to it?