how to create Synchronized arraylist

Question

i have created synchronized arrayList like this

import java.text.SimpleDateFormat;
import java.util.*;


class HelloThread  
{

 int i=1;
 List arrayList;
           


        

Answer 1

Consider using a CopyOnWriteArrayList which is thread-safe. Every time you add an item, a fresh copy of the underlying array is created. However, the iterator will not reflect additions to the list since the iterator was created, but is guaranteed not to throw ConcurrentModificationException.

arrayList=new CopyOnWriteArrayList();