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Reimplement the package-private CollectionUtils.CardinalityHelper using 

Bags instead of custom Maps
This commit is contained in:
Gary Gregory 2024-09-01 17:18:05 -04:00
parent a91ae587a2
commit 7e81d81962
1 changed files with 18 additions and 27 deletions
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45
src/main/java/org/apache/commons/collections4/CollectionUtils.java
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@ -63,26 +63,29 @@ public class CollectionUtils {
*/
private static class CardinalityHelper<O> {
private static final Integer ZERO = Integer.valueOf(0);
static boolean equals(final Collection<?> a, final Collection<?> b) {
return new HashBag<>(a).equals(new HashBag<>(b));
}
/** Contains the cardinality for each object in collection A. */
final Map<O, Integer> cardinalityA;
final Bag<O> cardinalityA;
/** Contains the cardinality for each object in collection B. */
final Map<O, Integer> cardinalityB;
final Bag<O> cardinalityB;
/**
* Create a new CardinalityHelper for two collections.
* Creates a new CardinalityHelper for two collections.
*
* @param a the first collection
* @param b the second collection
*/
CardinalityHelper(final Iterable<? extends O> a, final Iterable<? extends O> b) {
cardinalityA = getCardinalityMap(a);
cardinalityB = getCardinalityMap(b);
cardinalityA = new HashBag<>(a);
cardinalityB = new HashBag<>(b);
}
/**
* Returns the frequency of this object in collection A.
* Gets the frequency of this object in collection A.
*
* @param key the key whose associated frequency is to be returned.
* @return the frequency of the object in collection A
@ -92,7 +95,7 @@ public class CollectionUtils {
}
/**
* Returns the frequency of this object in collection B.
* Gets the frequency of this object in collection B.
*
* @param key the key whose associated frequency is to be returned.
* @return the frequency of the object in collection B
@ -101,12 +104,13 @@ public class CollectionUtils {
return getFreq(key, cardinalityB);
}
private int getFreq(final Object key, final Map<?, Integer> freqMap) {
return freqMap.getOrDefault(key, ZERO).intValue();
private int getFreq(final Object key, final Bag<?> freqMap) {
return freqMap.getCount(key);
}
/**
* Returns the maximum frequency of an object.
* Gets the maximum frequency of an object.
*
* @param obj the object
* @return the maximum frequency of the object
*/
@ -115,7 +119,8 @@ public class CollectionUtils {
}
/**
* Returns the minimum frequency of an object.
* Gets the minimum frequency of an object.
*
* @param obj the object
* @return the minimum frequency of the object
*/
@ -1257,21 +1262,7 @@ public class CollectionUtils {
* @throws NullPointerException if either collection is null
*/
public static boolean isEqualCollection(final Collection<?> a, final Collection<?> b) {
Objects.requireNonNull(a, "a");
Objects.requireNonNull(b, "b");
if (a.size() != b.size()) {
return false;
}
final CardinalityHelper<Object> helper = new CardinalityHelper<>(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;
return CardinalityHelper.equals(a, b);
}
/**