Java泛型强制执行抽象方法的返回类型 [英] Java generics to enforce return type of abstract method

问题描述

我有以下情况：

abstract class X { abstract X someMethod (...) {...} }.

现在我想约束X的任何实现，让它的'someMethod'方法返回特定的实现类型，而不仅仅是X：

Now I want to constrain any implementation of X to have its 'someMethod' method return that particular implementation type, not just X :

class X1 extends X { X1 someMethod (...) {...} }.
class X1 extends X { X someMethod (...) {...} }.  //want this to be flagged as an error
class X2 extends X { X1 someMethod (...) {...} }.  //want this to be flagged as an error too

是否可以使用Java泛型实现此目的？

Is it possible to achieve this using Java generics ?

编辑

好的。我只问了是/否问题并得到了是。我的错。我真正感兴趣的是如何编写声明。

Okay. I only asked the yes/no question and got a "yes". My fault. What I was actually interested in is "how do I write the declarations".

推荐答案

这也有效;

abstract class X<T> {
    public abstract T yourMethod();
}
class X1 extends X<X1> {
    public X1 yourMethod() {
        return this;
    }
}
class X2 extends X<X2> {
    public X2 yourMethod() {
        return this;
    }
}

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