Java 8:

int[] intArr = Arrays.stream(integerList).mapToInt(i->i).toArray();

Integer[] arr = (Integer[]) x.toArray(new Integer[x.size()]);

像正常int[]一样访问arr。

Arrays.setAll()适用于大多数场景:

Integer List to primitive int array: public static int[] convert(final List<Integer> list) { final int[] out = new int[list.size()]; Arrays.setAll(out, list::get); return out; } Integer List (made of Strings) to primitive int array: public static int[] convert(final List<String> list) { final int[] out = new int[list.size()]; Arrays.setAll(out, i -> Integer.parseInt(list.get(i))); return out; } Integer array to primitive int array: public static int[] convert(final Integer[] array) { final int[] out = new int[array.length]; Arrays.setAll(out, i -> array[i]); return out; } Primitive int array to Integer array: public static Integer[] convert(final int[] array) { final Integer[] out = new Integer[array.length]; Arrays.setAll(out, i -> array[i]); return out; }

你可以简单地将它复制到一个数组:

int[] arr = new int[list.size()];
for(int i = 0; i < list.size(); i++) {
    arr[i] = list.get(i);
}

不要太花哨;但是，嘿，它是有效的…

使用Dollar应该非常简单:

List<Integer> list = $(5).toList(); // the list 0, 1, 2, 3, 4  
int[] array = $($(list).toArray()).toIntArray();

我计划改进DSL，以删除中间的toArray()调用

这对我来说很好:)

网址:https://www.techiedelight.com/convert-list-integer-array-int/

import java.util.Arrays;
import java.util.List;

class ListUtil
{
    // Program to convert list of integer to array of int in Java
    public static void main(String args[])
    {
        List<Integer> list = Arrays.asList(1, 2, 3, 4, 5);

        int[] primitive = list.stream()
                            .mapToInt(Integer::intValue)
                            .toArray();

        System.out.println(Arrays.toString(primitive));
    }
}