I have two lists, I would like to compare them with each other and introduce differences, but my code does not work, what could be the problem? How would you do that?

private List<Payment> rbsList;
private List<Payment> partnerList;

public void compare() {
    try {
        for (Payment rbs : rbsList) {
            for (Payment partner : partnerList) {
                if (partner.getAccount().equals(rbs.getAccount()) && partner.getSum() == rbs.getSum()) {
                    rbs.setExist(true);
                    partner.setExist(true);
                }
            }
        }
    } catch (OutOfMemoryError | ConcurrentModificationException exception) {
        exception.printStackTrace();
    }

    notMatchedRBS = rbsList.stream().filter(r -> !r.isExist()).collect(Collectors.toList());
    notMatchedPartner = partnerList.stream().filter(p -> !p.isExist()).collect(Collectors.toList());

}

CodePudding user response：

The code seems to be ok. It's Important to define what equals means to you, let's say:

-> Two accounts are equals if both has the same Id.

I recommend you to check if Account's equals is properly defined. The same happens with getSum().

CodePudding user response：

1. In payment class, add implementation for equals() then you can just do: partner.equals(rbs) in the if.

2. Consider using Java stream instead of the two for loops:

        List<Payment> differences = rbsList.stream()
            .filter(element -> !partnerList.contains(element))
            .collect(Collectors.toList());