com.kotcrab.vis.usl.CollectionUtils Maven / Gradle / Ivy
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package com.kotcrab.vis.usl;
import java.util.*;
/** CollectionUtils copied from Apache Commons */
public class CollectionUtils {
/**
* Returns true iff the given {@link Collection}s contain
* exactly the same elements with exactly the same cardinality.
*
* That is, iff the cardinality of e in a is
* equal to the cardinality of e in b,
* for each element e in a or b.
*/
public static boolean isEqualCollection (final Collection a, final Collection b) {
if (a.size() != b.size()) {
return false;
} else {
Map mapa = getCardinalityMap(a);
Map mapb = getCardinalityMap(b);
if (mapa.size() != mapb.size()) {
return false;
} else {
Iterator it = mapa.keySet().iterator();
while (it.hasNext()) {
Object obj = it.next();
if (getFreq(obj, mapa) != getFreq(obj, mapb)) {
return false;
}
}
return true;
}
}
}
private static final int getFreq (final Object obj, final Map freqMap) {
try {
return ((Integer) (freqMap.get(obj))).intValue();
} catch (NullPointerException e) {
// ignored
} catch (NoSuchElementException e) {
// ignored
}
return 0;
}
/**
* Returns a {@link Map} mapping each unique element in
* the given {@link Collection} to an {@link Integer}
* representing the number of occurances of that element
* in the {@link Collection}.
* An entry that maps to null indicates that the
* element does not appear in the given {@link Collection}.
*/
public static Map getCardinalityMap (final Collection col) {
HashMap count = new HashMap();
Iterator it = col.iterator();
while (it.hasNext()) {
Object obj = it.next();
Integer c = (Integer) (count.get(obj));
if (null == c) {
count.put(obj, new Integer(1));
} else {
count.put(obj, new Integer(c.intValue() + 1));
}
}
return count;
}
}