Java：类型安全：为 varargs 参数创建 A 的通用数组
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Java: Type safety : A generic array of A is created for a varargs parameter
提问by Albert
Possible Duplicate:
Is it possible to solve the “A generic array of T is created for a varargs parameter” compiler warning?
Consider this is given:
考虑这是给定的：
interface A<T> { /*...*/ }
interface B<T> extends A<T> { /*...*/ }
class C { /*...*/ }
void foo(A<T>... a) { /*...*/ }
Now, some other code wants to use foo:
现在，其他一些代码想要使用foo：
B<C> b1 /* = ... */;
B<C> b2 /* = ... */;
foo(b1, b2);
This gives me the warning
这给了我警告
Type safety : A generic array of A is created for a varargs parameter
So I changed the call to this:
所以我把电话改成了这样：
foo((A<C>) b1, (A<C>) b2);
This still gives me the same warning.
这仍然给我同样的警告。
Why? How can I fix that?
为什么？我该如何解决？
回答by ColinD
All you can really do is suppress that warning with @SuppressWarnings("unchecked"). Java 7 will eliminate that warning for client code, moving it to the declaration of foo(A... a)rather than the call site. See the Project Coin proposal here.
您真正能做的就是使用@SuppressWarnings("unchecked"). Java 7 将消除对客户端代码的警告，将其移至声明foo(A... a)而不是调用站点。在此处查看 Project Coin 提案。
回答by Bert F
Edit: Answer updated to reflect that question was updated to show A is indeed generic.
编辑：答案已更新以反映该问题已更新以显示 A 确实是通用的。
I would think that A must be a generic to get that error. Is A a generic in your project, but the code sample above leaves the generic decl out?
我认为 A 必须是泛型才能获得该错误。A 是您项目中的泛型，但上面的代码示例没有使用泛型 decl 吗？
If so,Because A is generic,you can't work around warning cleanly. Varargs are implemented using an array and an array doesn't support generic arrays as explained here:
如果是这样，因为 A 是通用的，所以你不能干净地解决警告。Varargs 是使用数组实现的，数组不支持通用数组，如下所述：
回答by Eugene Kuleshov
You can try this:
你可以试试这个：
<T> void foo(T... a) { /*...*/ }
