Arrays.asList使用注意

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当传入的是基本类型时，会把传过来的数组作为list的第一个元素：

public class ArraysasList {public static void main(String[] args) {int[] a = {1,2,3,4,8,10,22,12,214,23};String[] b = {"a","b","c"};Integer[] c = {1,2,3,4,8,10,22,12,214,23};System.out.println(a);System.out.println(Arrays.asList(b));System.out.println(Arrays.asList(c));}}

输出结果：

[I@179935d
[a, b, c]
[1, 2, 3, 4, 8, 10, 22, 12, 214, 23]

Arrays第二个问题，在添加或者删除的时候会报错：

public class ArraysasList {public static void main(String[] args) {int[] a = {1,2,3,4,8,10,22,12,214,23};String[] b = {"a","b","c"};Integer[] c = {1,2,3,4,8,10,22,12,214,23};System.out.println(a);System.out.println(Arrays.asList(b));System.out.println(Arrays.asList(c));List<String> bList = Arrays.asList(b);bList.add("d");System.out.println(bList);}}

Exception in thread "main" java.lang.UnsupportedOperationException
   at java.util.AbstractList.add(AbstractList.java:148)
   at java.util.AbstractList.add(AbstractList.java:108)
   at ArraysasList.main(ArraysasList.java:16)

源码中写到：

public void add(int index, E element) {

07 throw new UnsupportedOperationException();

08}

09

10public E remove(int index) {

11 throw new UnsupportedOperationException();

12}

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