集合类不安全——Set_Sweet77

Set不安全

package com.qi.demo01.UnSafe;

import java.util.*;
import java.util.concurrent.CopyOnWriteArraySet;

/**
 * @author zjq
 * @date 2020/3/25 21:04
 */

/**
 * 同理可证：ConcurrentModificationException
 * 1.Set<String> set = Collections.synchronizedSet(new HashSet<>());
 * 2.Set<String> set = new CopyOnWriteArraySet<>();
 */
public class SetTest {
    public static void main(String[] args) {
        //Set<String> set = new HashSet<>();
        Set<String > set = new CopyOnWriteArraySet<>();

        for(int i = 0;i<30;i++){
            new Thread(()->{
                set.add(UUID.randomUUID().toString().substring(0,5));
                System.out.println(set);
            },String.valueOf(i)).start();

        }
    }
}
package com.qi.demo01.Un