JUC(java,util,concurrent)并发包，并发包中包含了许多并发编程中需要用到的类
package com.peng.cny; import java.util.concurrent.CopyOnWriteArrayList; //测试JUC包下的安全类型的集合 public class TestJUC { public static void main(String[] args) { //CopyOnWriteArrayList这个类的线程是安全的 CopyOnWriteArrayList<String> list = new CopyOnWriteArrayList<String>(); for (int i = 0; i < 10000; i++) { new Thread(()->{ list.add(Thread.currentThread().getName()); }).start(); } try { Thread.sleep(3000); } catch (InterruptedException e) { e.printStackTrace(); } System.out.println(list.size()); } }