如何获得泛型Enum的类型对象?例如:EnumSet.noneOf(< huh?>) [英] How do I get the type object of a genericized Enum? eg: EnumSet.noneOf(<huh?>)
问题描述
public class FlagsField< T extends Enum< p> 我有一个泛型类型,它在一些Enum上被参数化, ; T>> {
private EnumSet< T> _flagSet;
public FlagsField(){
_flagSet = EnumSet。< T> noneOf(/ *这是什么?* /);
}
...
}
我想像上面那样在构造函数中初始化_flagsField,但是无法弄清楚我的生活什么是noneOf方法的正确参数。它需要是 Class< T>
类型。如果这不是通用的,那么您可以在这里使用 MyFooEnumType.class
,但是 T.class
无效。
谢谢!
href =http://java.sun.com/docs/books/tutorial/java/generics/erasure.html =nofollow noreferrer>输入删除。您的构造函数将需要如下所示:
public FlagsField(Class< T> enumClass){
_flagSet = EnumSet< T> noneOf(enumClass);
}
I have a generic type that is parameterized on some Enum, declared like this:
public class FlagsField<T extends Enum<T>> {
private EnumSet<T> _flagSet;
public FlagsField() {
_flagSet = EnumSet.<T>noneOf( /* what goes here? */ );
}
...
}
I want to initialize _flagsField in the constructor as above, but can't figure out for the life of me what the right parameter to the noneOf method is. It needs to be of type Class<T>
. If this weren't a generic, you'd use MyFooEnumType.class
here, but T.class
is not valid.
Thanks!
You've run into type erasure. Your constructor is going to need to look like:
public FlagsField(Class<T> enumClass) {
_flagSet = EnumSet.<T>noneOf(enumClass);
}
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