static Type getSuperclassTypeParameter(Class<?> subclass)
{
Type superclass = subclass.getGenericSuperclass();
if (superclass instanceof Class)
{
throw new RuntimeException("Missing type parameter.");
}
ParameterizedType parameterized = (ParameterizedType) superclass;
return $Gson$Types.canonicalize(parameterized.getActualTypeArguments()[0]);
}
这里if (superclass instanceof Class)是什么意思?
// 如果 superclass指向的对象是Class类的实例,为true
if (superclass instanceof Class){
throw new RuntimeException("Missing type parameter.");
}