(CME并发修改异常)ConcurrentModificationException

/**
 * @author cf
 * @version 1.0
 */
public class ConcurrentModificationException {


	public static void main(String[] args)
	{
		Map<String,String> map = new ConcurrentHashMap<String,String>();//new HashMap<String,String>();
		
		for (int i = 1; i <=25; i++) 
		{
			new Thread(() -> {
				map.put(Thread.currentThread().getName(),UUID.randomUUID().toString().substring(0, 9));
				System.out.println(map);
			},String.valueOf(i)).start();
		}		
		
//		setNotSafe();
		//listNotSafe();
	}


//	不安全 CME异常 并发修改异常
	private static void setNotSafe()
	{
		Set<String> set = new CopyOnWriteArraySet<String>();//new HashSet<String>();
		
		for (int i = 1; i <=25; i++) 
		{
			new Thread(() -> {
				set.add(UUID.randomUUID().toString().substring(0, 9));
				System.out.println(set);
			},String.valueOf(i)).start();
		}
	}


	//arraylist 不安全 CME异常 并发修改异常
	private static void listNotSafe()
	{
//		List<String> list = new CopyOnWriteArrayList<String>();
		//ConcurrentModificationException并发修改异常
		List<String> list = new ArrayList<String>();
		
		//多线程+高并发			---->		写时复制技术
		for (int i = 1; i <=35; i++) 
		{
			new Thread(() -> {
				list.add(UUID.randomUUID().toString().substring(0, 9));
				System.out.println(list);
			},String.valueOf(i)).start();
		}
	}


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转载自blog.csdn.net/qq_35400008/article/details/80218543
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