为什么我会收到 int.class 转换的类转换异常

在下面的程序中我不明白为什么有ClassCastException为演员从int.class

Update:我应该指定我知道什么是原始类型。What I don't understand is why int.class is provided with broken implementation?

  public static void main(String[] args) {
    System.out.println(DataType.INT.getValue(Integer.class));
    System.out.println(DataType.INT.getValue(int.class));//Class cast exception here
}

enum DataType {
    INT {
        @Override
        public <T> T getValue(Class<T> toClass) {
            return toClass.cast(1000);//ClassCastException here for int.class
        }
    };
    public abstract <T> T getValue(Class<T> toClass);

}

发生这种情况是因为cast()操作Class uses isInstance() method which returns false for primitive classes.

如果此 Class 对象表示基本类型，则此方法返回 false。

代码为cast()方法如下

public T cast(Object obj) {
if (obj != null && !isInstance(obj))//It fails here since isInstance returns false
    throw new ClassCastException();
return (T) obj;