type/2 (i,io)
This predicate returns in the second argument the name of the Java class of the object supplied as input in the first argument. The output may already be set to a String value, which will then return success if the class name of the supplied object matches that string.
The following fragment will print the name of the ArrayList class..
List=java.util.ArrayList(), type(List,TypeList), println([TypeList]),
This prints
java.util.ArrayList