ArrayList.add throws ArrayIndexOutOfBoundsException [duplicate]

Answer 1

The code you posted will not throw ArrayIndexOutOfBoundsException.

The exception you get is thrown in the part you omitted. Take a look at your stacktrace. Its InboxSearchBean that causes the exception. Most likely it performs a get(index) on the list with an invalid index.

Answer 2

ArrayList.add() should never throw an ArrayIndexOutOfBoundsException if used "properly" so it seems that you're using your ArrayList in a way which it does not support.

It's hard to tell from just the code you've posted but my guess is that you're accessing your ArrayList from multiple threads.

ArrayList isn't synchronised and so isn't thread safe. If this is the problem you can fix it by wrapping your List using Collections.synchronizedList().

Changing your code to the following should resolve the problem:

private void populateInboxResultHolder(List inboxErrors){
    List inboxList = Collections.synchronizedList(new ArrayList());
    try{                
        inboxHolder = new InboxResultHolder();
        //Lots of Code
        inboxList.add(inboxHolder);
    }catch(Exception e){
        e.printStackTrace();
    }
}