class SelfBounded<T extends SelfBounded<T>>{ T element; SelfBounded<T> set(T arg){ element = arg; return this; } T get() { return element; } } class A extends SelfBounded<A>{} // class E extends SelfBounded<D>{} 会报错
格式: class SelfBounded<T extends SelfBounded<T>>
自限定会强制要求正在定义的类当做参数传递给基类.看格式就能看出来.
原文：https://www.cnblogs.com/lishuaiqi/p/10403875.html