Question

In the below code I’m getting the following error :

java.lang.IndexOutOfBoundsException: Index: 1, Size: 1

The size is 1 for copiedppList.size()

for (int domainData = 0; domainData < copiedppList.size(); domainData++) {
    if (domainData == 0) {
        firstValue.setNewValue(firstValue.getFieldValue());
        DomainItemFieldHistory oldValue = copiedppList.get(domainData + 1);
        if (firstValue.getFieldID().equals(oldValue.getFieldID())) {
            firstValue.setOldValue(oldValue.getFieldValue());
        }
    }
}

The below line is causing the mentioned issue:

DomainItemFieldHistory oldValue = copiedppList.get(domainData + 1); 

How can i avoid this?
What condition can be added to prevent the error?

Answer 1

Changing the terminating condition to copiedppList.size() - 1 will prevent the out of bounds exception.

Array indexes are zero based, so the last valid index is size() - 1. The posted code can iterate to size() - 1 but makes the following call:

copiedppList.get(domainData + 1);

causing the exception.

If the loop must iterate over all elements then you need to protect the + 1 call. For example:

if (domainData < copiedppList.size() - 1)
{
    copiedppList.get(domainData + 1); // This is now safe, assuming
                                      // nothing reduces the size of
                                      // copiedppList since the if check.
}