如何使用动态参数对比较器进行排序？

Question

是否可以创建静态（因此我不必在每次比较时重新创建对象），但仍会传递用于比较的动态值？Comparator

在下面的示例中，我想在比较期间传递一个参数。但是如何做到呢？String dynaval

private final Comparator<Person> COMPARATOR = Comparator.comparing(person -> {

     if (person.getFirstname() != null) return person.getFirstname();

     return evaluateWithDynamicProperty(person, dynaval);

}

Collections.sort(persons, COMPARATOR); //TODO how to pass dynamic String?

Answer 1

制作一个方法：private final Comparator<Person> personComparator(String dynaValue) {&nbsp; return Comparator.comparing(person -> {&nbsp; &nbsp; &nbsp;if (person.getFirstname() != null) return person.getFirstname();&nbsp; &nbsp; &nbsp;return evaluateWithDynamicProperty(person, dynaval);}调用类似如下：Collections.sort(persons, personComparator(dynaValue));或者，使用 λ：String personComparatorFn(Person person, String dynaValue) {&nbsp; &nbsp; &nbsp;if (person.getFirstname() != null) return person.getFirstname();&nbsp; &nbsp; &nbsp;return evaluateWithDynamicProperty(person, dynaval);}并调用如下：Collections.sort(persons, Comparator.comparing(p -> personComparatorFn(p, dynaValue));