[COLLECTIONS-600] Make CollectionUtils (in particular isEqualCollection) null-safe

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 4.1
• Component/s: Collection
• Assignee: Unassigned
• Reporter: Jonas Holtkamp
• Created: 08/Feb/17 21:35
• Updated: 09/Feb/22 11:14

Description

Other Commons *Utils classes as StringUtils etc. feature null-safe methods. Why doesn't for example CollectionUtils#isEqualCollection include a null check, like this?

    public static boolean isEqualCollection(final Collection<?> a, final Collection<?> b) {
        if(a == null || b == null) {
            return false;
        }
        if(a.size() != b.size()) {
            return false;
        }
        final CardinalityHelper<Object> helper = new CardinalityHelper<Object>(a, b);
        if(helper.cardinalityA.size() != helper.cardinalityB.size()) {
            return false;
        }
        for( final Object obj : helper.cardinalityA.keySet()) {
            if(helper.freqA(obj) != helper.freqB(obj)) {
                return false;
            }
        }
        return true;
    }

I considered filing a Pull Request but wanted to ask here first.

Issue Links

• depends upon: COLLECTIONS-604 More uniform safe-null methods in CollectionUtils
• links to: GitHub Pull Request #22