Java Reference
In-Depth Information
♦
m
2
is
public
,
protected
, or declared with default access in the same package as
C
,
or
♦
m
1
overrides a method
m
3
(
m
3
distinct from
m
1
,
m
3
distinct from
m
2
), such that
m
3
overrides
m
2
.
Moreover, if
m
1
is not
abstract
, then
m
1
is said to
implement
any and all declarations of
ab-
stract
methods that it overrides.
The signature of an overriding method may differ from the overridden one if a formal
parameter in one of the methods has a raw type, while the corresponding parameter in
the other has a parameterized type.
The rules allow the signature of the overriding method to differ from the overridden
one, to accommodate migration of pre-existing code to take advantage of generics.
See §
8.4.2
for further analysis.
It is a compile-time error if an instance method overrides a
static
method.
In this respect, overriding of methods differs from hiding of fields (§
8.3
), for it is per-
missible for an instance variable to hide a
static
variable.
that contains the keyword
super
.
A qualified name or a cast to a superclass type is not effective in attempting to access
an overridden method; in this respect, overriding of methods differs from hiding of fields
The presence or absence of the
strictfp
modifier has absolutely no effect on the rules for
overriding methods and implementing abstract methods. For example, it is permitted for a
method that is not FP-strict to override an FP-strict method and it is permitted for an FP-
strict method to override a method that is not FP-strict.
Example 8.4.8.1-1. Overriding
class Point {
int x = 0, y = 0;
void move(int dx, int dy) { x += dx; y += dy; }
}
class SlowPoint extends Point {
int xLimit, yLimit;
void move(int dx, int dy) {
