java - 多线程iterator修改ArrayList为何没有抛出ConcurrentModificationException异常？

Answer 1

ArrayList is not inherently thread-safe. You can try it with the List returned by Collections.synchronizedList()

Answer 2

In this example, the two cases of ArrayList and CopyOnWriteArrayList are tested respectively. ArrayList will generate fast-fail events, but CopyOnWriteArrayList will not generate fast-fail events.

When using ArrayList, a fast-fail event will be generated and a ConcurrentModificationException exception will be thrown; the definition is as follows:

private static List<String> list = new ArrayList<String>();

When using CopyOnWriteArrayList, no fast-fail event will be generated; the definition is as follows:

private static List<String> list = new CopyOnWriteArrayList<String>();

Answer 3

If it is set to 100000000, an exception will be thrown. . .

Use CopyOnWriteArrayList or ThreadLocal to put ArrayList in multi-threads