Java中的Arrays的asList的坑

Java中的Arrays的asList的坑 错误案例

package com;
import java.util.Arrays;
import java.util.List;

public class ArrayAsListTest {
    public static void main(String[] args) {
        String[] arr = new String[]{"a","b","c"};
        List arrayList = Arrays.asList(arr);
        arrayList.add("d");
    }
}

错误原理

此ArrayList非彼ArrayList ， java.util.Arrays.ArrayList.ArrayList 它是array类的一个内部类

正确代码

package com;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class ArrayAsListTest {
    public static void main(String[] args) {
//        String[] arr = new String[]{"a","b","c"};
//        List arrayList = Arrays.asList(arr);
//        arrayList.add("d");

        String[] arr = new String[]{"a","b","c"};
        List arrayList = new ArrayList<>(Arrays.asList(arr));
        arrayList.add("d");
        System.out.println(arrayList.size());
    }
}