如何根据 kotlinjava 中的另一个列表过滤列表

It looks ok to me. I would only change some minor things (not required though), so that it ends up something like the following:

 fun List<FooModel>.f(fooApiList: List<FooApi>) = filter { m -> fooApiList.any { it.aId == m.mId } }

Some reasons why I did it this way:

• I think that filtering is always applied on a list of FooModels, right? (that is the reason for the extension function narrowing the type to List<FooModel>)
• You are not interested in the mapped object of fooApiList, so that is why I used any instead; the nice benefit there also is that now both values that are compared are next to each other
• 总结一切都很容易，您甚至可以省略方法体(因此可以省略返回类型、返回语句等).

Still, that's nearly the same as you did already... Just a bit less code and a rearrangement... Calling it by the way would look like:

val listA : List<FooModel> = TODO()
val listB : List<FooApi> = TODO()

val containedList = listA.f(listB)

If you require such a construct more often, maybe the following more generic solution is helpful:

fun <T, U> List<T>.intersect(uList: List<U>, filterPredicate : (T, U) -> Boolean) = filter { m -> uList.any { filterPredicate(m, it)} }

Which you can then also use like:

val containedList = listA.intersect(listB) {
    a, b -> a.aId == b.mId
}

Then your f again might even look just like:

fun List<FooModel>.f(fooApiList: List<FooApi>) = intersect(fooApiList) { a, b ->  a.mId == b.aId }