如果不支持添加或删除元素,将Array转换为ArrayList有什么用？

Question

我尝试了以下内容,并java.lang.UnsupportedOperationException在尝试向其添加新元素时看到它抛出.

基本上我尝试将Array转换为ArrayList,并尝试在从数组到ArrayList协调后添加新元素.

我的计划是:

public class ArrayToList {
    public static void main(String[] args) {
        String[] asset = {"equity", "stocks", "gold", "foreign exchange","fixed income", "futures", "options"}; 
        List<String>  assetList = Arrays.asList(asset);

        for (String object : assetList) {
            System.out.println("object : "+object);
        }

        assetList.add("test");
    }

}

例外:

Exception in thread "main" java.lang.UnsupportedOperationException
    at java.util.AbstractList.add(Unknown Source)
    at java.util.AbstractList.add(Unknown Source)
    at anto.com.collection.ArrayToList.main(ArrayToList.java:15)

如果我们无法在转换后的值中添加或删除元素,那么从数组转换为Arraylist有什么用？

谢谢

Answer 1

Arrays.asList - 返回由指定数组支持的固定大小的列表.您无法在固定大小上添加新元素List.添加新元素定义List为

  List<String>  assetList = new ArrayList(Arrays.asList(asset));