package J20250730.demo12_synchronizedCollection; import java.util.ArrayList; import java.util.Collections; import java.util.List; /** * @author WanJl * @version 1.0 * @title Demo01 * @description * @create 2025/7/30 */ public class Demo01 { public static void main(String[] args) { ArrayList l=new ArrayList<>(); //这就是把线程不安全的集合,封装为线程安全的集合 List list = Collections.synchronizedList(l); } }