On how ArrayList implements thread security, and how arraylist implements threads

On how ArrayList implements thread security, and how arraylist implements threads

I. Use the synchronized keyword

2. Use Collections. synchronizedList ();

Assume that the code you created is as follows: List <Map <String, Object> data = new ArrayList <Map <String, Object> ();

To solve this thread security problem, you can use Collections. synchronizedList (), for example:

List <Map <String, Object> data = Collections. synchronizedList (new ArrayList <Map <String, Object> ());

The methods used are almost the same as those of ArrayList. For details, refer to the api documentation;

In addition, ArrayList and javaslist are both an implementation under the interface List, which have the same usage, but the places used are a bit different. ArrayList is suitable for a large number of random accesses, the rule list is suitable for table insertion and deletion. Both are non-thread-safe. The solution is the same as above (to avoid thread security, the above method is used, especially the second method, in fact, it is very performance-consuming ).