Java Reference
In-Depth Information
Now, any implementing class must pass to
Containment
a type argument also having
the same bound. For example, now
MyClass
must be declared as shown here:
Pay special attention to the way the type parameter
T
is declared by
MyClass
and then
passed to
Containment
. Because
Containment
now requires a type that extends
Number
,
the implementing class (
MyClass
in this case) must specify the same bound. Furthermore,
once this bound has been established, there is no need to specify it again in the
implements
clause. In fact, it would be wrong to do so. For example, this declaration is incorrect and
won't compile:
Once the type parameter has been established, it is simply passed to the interface without
further modification.
Here is the generalized syntax for a generic interface:
interface
interface-name
<
type-param-list
> { // …
Here,
type-param-list
is a comma-separated list of type parameters. When a generic inter-
face is implemented, you must specify the type arguments, as shown here:
class
class-name
<
type-param-list
>
implements
interface-name
<
type-param-list
> {
Try This 13-1
Create a Generic Queue
