| Compares its two arguments for order. Returns a negative integer,
zero, or a positive integer as the first argument is less than, equal
to, or greater than the second.
The implementor must ensure that sgn(compare(x, y)) ==
-sgn(compare(y, x)) for all x and y. (This
implies that compare(x, y) must throw an exception if and only
if compare(y, x) throws an exception.)
The implementor must also ensure that the relation is transitive:
((compare(x, y)>0) && (compare(y, z)>0)) implies
compare(x, z)>0.
Finally, the implementer must ensure that compare(x, y)==0
implies that sgn(compare(x, z))==sgn(compare(y, z)) for all
z.
It is generally the case, but not strictly required that
(compare(x, y)==0) == (x.equals(y)). Generally speaking,
any comparator that violates this condition should clearly indicate
this fact. The recommended language is "Note: this comparator
imposes orderings that are inconsistent with equals."
Parameters:
o1 - the first object to be compared.
Parameters:
o2 - the second object to be compared. a negative integer, zero, or a positive integer as thefirst argument is less than, equal to, or greater than thesecond.
throws:
ClassCastException - if the arguments' types prevent them frombeing compared by this Comparator. |
