ArrayList won't Add more than one Item

Question

My Array will not add anything to the list after the first and keeps returning null when i search for anything after.

Is there something wrong with this method?

public void addItem(Item newItem) throws DuplicateItemException {
    Item tempItem;

    if(itemList == null) 
        itemList.add(newItem);

    try {
        tempItem = findItem(newItem.ID);

        if(tempItem == null) {
            itemList.add(newItem);
        }
        else {
            throw new DuplicateItemException(newItem.ID + "already exists");
        }
    } 
    catch (ItemNotFoundException e) {
        itemList.add(newItem);
    }
}

Answer 1

In your code:

if(itemList == null) 
    itemList.add(newItem);

if itemList is indeed null , how can you add to it?

Use this instead

if(itemList == null) {
    itemList = new ArrayList<>();
    itemList.add(newItem);
}