问题描述
我的Java代码引发了以下异常:
My java code threw the following exception:
java.lang.IllegalArgumentException: Comparison method violates its general contract!
我研究了StackOverflow上的消息,发现了几个问题,这些问题张贴了他们写得不好的比较方法,但是我想知道合同写在哪里,以及关于比较方法必须做什么的确切说明.
I researched the message on StackOverflow and found several questions that posted their poorly written compare methods, but I was wondering where the contract is written and what exactly does it state regarding what the compare method must do.
推荐答案
类似 Java文档 拥有
实现者还必须确保该关系是可传递的:(((compare(x,y)> 0)&&(compare(y,z)> 0))表示compare(x,z)> 0.
The implementor must also ensure that the relation is transitive: ((compare(x, y)>0) && (compare(y, z)>0)) implies compare(x, z)>0.
最后,实现者必须确保compare(x,y)== 0意味着所有z的sgn(compare(x,z))== sgn(compare(y,z)).
Finally, the implementor must ensure that compare(x, y)==0 implies that sgn(compare(x, z))==sgn(compare(y, z)) for all z.
通常是这种情况,但不是严格要求(compare(x,y)== 0)==(x.equals(y)).一般来说,任何比较器违反此条件应清楚地表明这一事实.这推荐的语言是注意:此比较器强加了以下命令:与等式不一致."
It is generally the case, but not strictly required that (compare(x, y)==0) == (x.equals(y)). Generally speaking, any comparator that violates this condition should clearly indicate this fact. The recommended language is "Note: this comparator imposes orderings that are inconsistent with equals."
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