问题
The following quote is from
JLS 14.20
The declared type of an exception parameter that denotes its type as a union with alternatives D1 | D2 | ... | Dn is lub(D1, D2, ..., Dn).
What is the lub(D1,...Dn) here?
回答1:
It stands for "Least Upper Bound" and is formally defined in §4.10.4. Least Upper Bound:
The least upper bound, or "lub", of a set of reference types is a shared supertype that is more specific than any other shared supertype (that is, no other shared supertype is a subtype of the least upper bound).
回答2:
It stands for least upper bound. See JLS 4.10.4.
来源：https://stackoverflow.com/questions/26193918/what-does-lubt1-tn-mean