是否有一种干净的方法将泛型类型的类分配给变量?-IsthereacleanwaytoassigntheClassofagenerictypetoavariable?

5  

This is a real Catch-22 in Java.

这是Java中真正的Catch-22。

The compiler warns you if you don't add a generic type to List:

如果不向列表中添加泛型类型，编译器会警告您:

// WARN: List is not typed
Class typeTry3 = ints.getClass();

That's because, in most cases, it's really best to type your Lists.

这是因为，在大多数情况下，最好键入列表。

However, because of type erasure, there's no way for Java to figure out the generic type of List at runtime, and the compiler knows that. Therefore, there is no method on Class that will returned a typed object:

但是，由于类型擦除，Java无法在运行时确定列表的泛型类型，编译器知道这一点。因此，在类上没有返回类型化对象的方法:

// ERROR: ints.getClass() doesn't return a Class>, it returns a Class
Class> var = ints.getClass();

So you must cast it to a typed list. However, as you know, since there is no runtime type checking, Java warns you about any casts to a typed variable:

因此，您必须将其转换为类型化列表。但是，正如您所知道的，由于没有运行时类型检查，Java警告您任何类型变量的类型转换:

// WARN: Casting to typed List
Class> typeTry2 = (Class>) ints.getClass();

Any attempt to get around this is essentially a means of confusing the compiler, and will inevitably be convoluted.

任何试图绕过它的尝试本质上都是一种混淆编译器的方法，并且不可避免地会令人费解。

Your best bet then is to go with Option B:

你最好的选择是选择B:

On the other hand, if warning suppression is the only way, what is the safest to suppress?

另一方面，如果警告抑制是唯一的方法，那么最安全的抑制方法是什么?

The safest way to suppress this warning is to make your @SuppressWarnings("unchecked") annotation as localized as possible. Put them above each individual unchecked cast. That way it's absolutely clear who's causing the warning.

抑制这个警告的最安全的方法是使您的@SuppressWarnings(“unchecked”)注释尽可能本地化。将它们放在每个未选中的cast上面。这样一来，谁会发出警告就一目了然了。

3  

One way to do this would be to create your own class. I am not sure if this would meet your needs.

一种方法是创建自己的类。我不确定这是否能满足你的需要。

I am not really sure what you are trying to achieve. So perhaps wildcards is the answer.

我不太确定你想要达到的目标。所以也许通配符就是答案。

import java.util.*;

class Main
{
      public static void main(String[] args)
      {
            List list = new ArrayList();
            Class clazz = list.getClass();
            System.out.println(clazz) ;
      }
}