获取T.class

public class GenericDemo<T>
{
    public Class<T> tClass;

    public GenericDemo(){

        ParameterizedType parameterizedType = (ParameterizedType) getClass().getGenericSuperclass();
        Type[] actualTypeArguments = parameterizedType.getActualTypeArguments();
        tClass = (Class<T>) actualTypeArguments[0];

    }
}