（取消）在Java中装箱原始数组 [英] (Un)boxing primitive arrays in Java

问题描述

在Android Java世界中，是否有一种简便的方法（最好是一次调用）将 int 的数组转换为 ArrayList< Integer> ; 然后返回？在ArrayList上调用 toArray（）会返回 Integer 的数组-不完全是我想要的。

in the Android Java world, is there a straighforward (ideally one-call) way to convert an array of int to an ArrayList<Integer> and back? Calling toArray() on the ArrayList returns an array of Integer - not quite what I want.

我可以轻松地手动执行一个循环（实际上已经做到了）。我想知道库/语言是否支持相同的语言。

I can easily do that by hand with a loop (already did, in fact). I'm wondering if the library/language supports the same.

编辑：谢谢，我已经写了自己的拳击手和拆箱手。我只是感到惊讶，语言/ RTL设计师自己没有想到这一点，特别是在原始类型被设计为不适合集合的情况下。

thanks all, I already wrote my own boxer and unboxer. I'm just surprised the language/RTL designers didn't think of it themselves, especially with primitive types being by design ineligible for collections.

推荐答案

使用番石榴（ Ints.asList（int ...）和 Ints.toArray（Collection< Integer>））：

int[] intArray = ...
List<Integer> intArrayAsList = Ints.asList(intArray);
int[] intArray2 = Ints.toArray(intArrayAsList);

请注意，例如 Arrays.asList ， Ints.asList 返回一个列表，该列表是给定数组的视图。您不能对其进行添加或删除，但是可以设置特定索引处的值。您还可以根据需要将其复制到新的 ArrayList ：

Note that like Arrays.asList, Ints.asList returns a list that is a view of the given array. You can't add to or remove from it, but you can set the value at a specific index. You can also copy it to a new ArrayList if you want:

List<Integer> arrayList = Lists.newArrayList(Ints.asList(intArray));

番石榴对所有原始类型都具有相同的方法。

Guava has the same methods for all primitive types.

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