Synchronize arraylist

Method 1) ArrayList al=new ArrayList();
al.add("1");
al.add("1");
al.add("2");
//we can make the synchronized

Collections.synchronized(al);


Method 2)
List list = Collections.synchronizedList(new ArrayList(...));

synchronized(list) {
Iterator i = list.iterator(); // Must be in synchronized block
while (i.hasNext())
foo(i.next());
}