Class Comparators

java.lang.Object

org.eclipse.collections.impl.block.factory.Comparators

public final class Comparators
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static final class	Comparators.AscendingCollectionSizeComparator
private static final class	Comparators.ByFirstOfPairComparator<T>
private static final class	Comparators.BySecondOfPairComparator<T>
private static final class	Comparators.ChainedComparator<T>
private static class	Comparators.ComparableComparator<T>
private static final class	Comparators.DescendingCollectionSizeComparator
private static final class	Comparators.FromPredicateSerializableComparator<T>
private static final class	Comparators.NaturalOrderComparator<T extends Comparable<T>>
private static final class	Comparators.PowerSetComparator<T>
private static final class	Comparators.ReverseComparator<T>
private static final class	Comparators.SafeNullsHighComparator<T>
private static final class	Comparators.SafeNullsLowComparator<T>

Field Summary

Fields

Modifier and Type	Field	Description
private static final SerializableComparator<Collection<?>>	ASCENDING_COLLECTION_SIZE_COMPARATOR
private static final SerializableComparator<?>	COMPARABLE_COMPARATOR
private static final SerializableComparator<Collection<?>>	DESCENDING_COLLECTION_SIZE_COMPARATOR
private static final SerializableComparator<?>	NATURAL_ORDER_COMPARATOR
private static final SerializableComparator<?>	POWER_SET_COMPARATOR
private static final SerializableComparator<?>	REVERSE_NATURAL_ORDER_COMPARATOR

Constructor Summary

Constructors

Modifier	Constructor	Description
private	Comparators()

Method Summary

Modifier and Type	Method	Description
static SerializableComparator<Collection<?>>	ascendingCollectionSizeComparator()
static <T> SerializableComparator<T>	byBooleanFunction(BooleanFunction<T> function)
static <T> SerializableComparator<T>	byByteFunction(ByteFunction<T> function)
static <T> SerializableComparator<T>	byCharFunction(CharFunction<T> function)
static <T> SerializableComparator<T>	byDoubleFunction(DoubleFunction<T> function)
static <T> SerializableComparator<Pair<T,?>>	byFirstOfPair(Comparator<? super T> comparator)	Creates a comparator for pairs by using an existing comparator that only compares the first element of the pair
static <T> SerializableComparator<T>	byFloatFunction(FloatFunction<T> function)
static <T, V extends Comparable<? super V>> SerializableComparator<T>	byFunction(Function<? super T, ? extends V> function)
static <T,V> SerializableComparator<T>	byFunction(Function<? super T, ? extends V> function, Comparator<V> comparator)	Original signature accepted a Comparator which may not be Serializable.
static <T, V extends Comparable<? super V>> SerializableComparator<T>	byFunctionNullsFirst(Function<? super T, ? extends V> function)
static <T, V extends Comparable<? super V>> SerializableComparator<T>	byFunctionNullsLast(Function<? super T, ? extends V> function)
static <T> SerializableComparator<T>	byIntFunction(IntFunction<T> function)
static <T> SerializableComparator<T>	byLongFunction(LongFunction<T> function)
static <T> SerializableComparator<Pair<?,T>>	bySecondOfPair(Comparator<? super T> comparator)	Creates a comparator for pairs by using an existing comparator that only compares the second element of the pair
static <T> SerializableComparator<T>	byShortFunction(ShortFunction<T> function)
static <T> SerializableComparator<T>	chain(Comparator<T>... comparators)
static <T> SerializableComparator<T>	comparableComparator()
static <T> Comparator<? super T>	comparableComparatorIfNull(Comparator<? super T> comparator)
static SerializableComparator<Collection<?>>	descendingCollectionSizeComparator()
static <T, V extends Comparable<? super V>> SerializableComparator<T>	fromFunctions(Function<? super T, ? extends V> one)
static <T, V1 extends Comparable<? super V1>, V2 extends Comparable<? super V2>> SerializableComparator<T>	fromFunctions(Function<? super T, ? extends V1> one, Function<? super T, ? extends V2> two)
static <T, V1 extends Comparable<? super V1>, V2 extends Comparable<? super V2>, V3 extends Comparable<? super V3>> SerializableComparator<T>	fromFunctions(Function<? super T, ? extends V1> one, Function<? super T, ? extends V2> two, Function<? super T, ? extends V3> three)
static <T> SerializableComparator<T>	fromPredicate(BiPredicate<? super T, ? super T> isBeforePredicate)
private static <T, V extends Comparable<? super V>> SerializableComparator<T>	getPrimitiveFunctionComparator(Function<? super T, ? extends V> function)
static <T> SerializableComparator<T>	naturalOrder()	Uses the natural compareTo methods of the objects which will throw if there are any nulls.
static <T extends Comparable<T>> int	nullSafeCompare(T value1, T value2)
static boolean	nullSafeEquals(Object value1, Object value2)
static <T, V extends Comparable<? super V>> SerializableComparator<T>	originalByFunction(Function<? super T, ? extends V> function)	Deprecated.
static <T,V> SerializableComparator<T>	originalByFunction(Function<? super T, ? extends V> function, Comparator<V> comparator)	Deprecated.
static <T> SerializableComparator<T>	originalNaturalOrder()	Deprecated.
static <T> SerializableComparator<T>	originalReverseNaturalOrder()	Deprecated.
static <T> SerializableComparator<SortedSetIterable<T>>	powerSet()
static <T> SerializableComparator<T>	reverse(Comparator<T> comparator)
static <T> SerializableComparator<T>	reverseNaturalOrder()	Uses the natural compareTo methods of the objects which will throw if there are any nulls.
static <T> SerializableComparator<T>	safeNullsHigh(Comparator<T> notNullSafeComparator)
static <T> SerializableComparator<T>	safeNullsLow(Comparator<T> notNullSafeComparator)

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

COMPARABLE_COMPARATOR

private static final SerializableComparator<?> COMPARABLE_COMPARATOR

NATURAL_ORDER_COMPARATOR

private static final SerializableComparator<?> NATURAL_ORDER_COMPARATOR

REVERSE_NATURAL_ORDER_COMPARATOR

private static final SerializableComparator<?> REVERSE_NATURAL_ORDER_COMPARATOR

POWER_SET_COMPARATOR

private static final SerializableComparator<?> POWER_SET_COMPARATOR

ASCENDING_COLLECTION_SIZE_COMPARATOR

private static final SerializableComparator<Collection<?>> ASCENDING_COLLECTION_SIZE_COMPARATOR

DESCENDING_COLLECTION_SIZE_COMPARATOR

private static final SerializableComparator<Collection<?>> DESCENDING_COLLECTION_SIZE_COMPARATOR

Constructor Details

Comparators

private Comparators()

Method Details

comparableComparator

public static <T> SerializableComparator<T> comparableComparator()

Since:

10.0

comparableComparatorIfNull

public static <T> Comparator<? super T> comparableComparatorIfNull(Comparator<? super T> comparator)

Since:

10.0

naturalOrder

public static <T> SerializableComparator<T> naturalOrder()

Uses the natural compareTo methods of the objects which will throw if there are any nulls.

originalNaturalOrder

@Deprecated
public static <T> SerializableComparator<T> originalNaturalOrder()

Deprecated.

This method exists in order to guarantee serialization compatibility in tests.

Since:

11.1

reverseNaturalOrder

public static <T> SerializableComparator<T> reverseNaturalOrder()

Uses the natural compareTo methods of the objects which will throw if there are any nulls.

originalReverseNaturalOrder

@Deprecated
public static <T> SerializableComparator<T> originalReverseNaturalOrder()

Deprecated.

This method exists in order to guarantee serialization compatibility in tests.

Since:

11.1

reverse

public static <T> SerializableComparator<T> reverse(Comparator<T> comparator)

Parameters:

comparator - original comparator whose order will be reversed

Returns:

A comparator that reverses the order of any other Serializable Comparator.

safeNullsLow

public static <T> SerializableComparator<T> safeNullsLow(Comparator<T> notNullSafeComparator)

safeNullsHigh

public static <T> SerializableComparator<T> safeNullsHigh(Comparator<T> notNullSafeComparator)

chain

@SafeVarargs
public static <T> SerializableComparator<T> chain(Comparator<T>... comparators)

fromFunctions

public static <T, V extends Comparable<? super V>>
SerializableComparator<T> fromFunctions(Function<? super T, ? extends V> one)

fromFunctions

public static <T, V1 extends Comparable<? super V1>, V2 extends Comparable<? super V2>>
SerializableComparator<T> fromFunctions(Function<? super T, ? extends V1> one,
 Function<? super T, ? extends V2> two)

fromFunctions

public static <T, V1 extends Comparable<? super V1>, V2 extends Comparable<? super V2>, V3 extends Comparable<? super V3>>
SerializableComparator<T> fromFunctions(Function<? super T, ? extends V1> one,
 Function<? super T, ? extends V2> two,
 Function<? super T, ? extends V3> three)

powerSet

public static <T>
SerializableComparator<SortedSetIterable<T>> powerSet()

ascendingCollectionSizeComparator

public static SerializableComparator<Collection<?>> ascendingCollectionSizeComparator()

descendingCollectionSizeComparator

public static SerializableComparator<Collection<?>> descendingCollectionSizeComparator()

byFirstOfPair

public static <T> SerializableComparator<Pair<T,?>> byFirstOfPair(Comparator<? super T> comparator)

Creates a comparator for pairs by using an existing comparator that only compares the first element of the pair

Parameters:

comparator - original comparator that compares the first element of the pair

Returns:

A comparator that compares pairs only by their first element

bySecondOfPair

public static <T> SerializableComparator<Pair<?,T>> bySecondOfPair(Comparator<? super T> comparator)

Creates a comparator for pairs by using an existing comparator that only compares the second element of the pair

Parameters:

comparator - original comparator that compares the second element of the pair

Returns:

A comparator that compares pairs only by their second element

fromPredicate

public static <T> SerializableComparator<T> fromPredicate(BiPredicate<? super T, ? super T> isBeforePredicate)

Parameters:

isBeforePredicate - a predicate that returns true if the first argument is less than, or should appear before, the second argument

Since:

12.0.0

byFunction

public static <T, V extends Comparable<? super V>>
SerializableComparator<T> byFunction(Function<? super T, ? extends V> function)

originalByFunction

@Deprecated
public static <T, V extends Comparable<? super V>>
SerializableComparator<T> originalByFunction(Function<? super T, ? extends V> function)

Deprecated.

This signature is kept for serialization backwards compatibility.

Since:

11.1

getPrimitiveFunctionComparator

private static <T, V extends Comparable<? super V>>
SerializableComparator<T> getPrimitiveFunctionComparator(Function<? super T, ? extends V> function)

byFunctionNullsLast

public static <T, V extends Comparable<? super V>>
SerializableComparator<T> byFunctionNullsLast(Function<? super T, ? extends V> function)

byFunctionNullsFirst

public static <T, V extends Comparable<? super V>>
SerializableComparator<T> byFunctionNullsFirst(Function<? super T, ? extends V> function)

byBooleanFunction

public static <T> SerializableComparator<T> byBooleanFunction(BooleanFunction<T> function)

byByteFunction

public static <T> SerializableComparator<T> byByteFunction(ByteFunction<T> function)

byCharFunction

public static <T> SerializableComparator<T> byCharFunction(CharFunction<T> function)

byDoubleFunction

public static <T> SerializableComparator<T> byDoubleFunction(DoubleFunction<T> function)

byFloatFunction

public static <T> SerializableComparator<T> byFloatFunction(FloatFunction<T> function)

byIntFunction

public static <T> SerializableComparator<T> byIntFunction(IntFunction<T> function)

byLongFunction

public static <T> SerializableComparator<T> byLongFunction(LongFunction<T> function)

byShortFunction

public static <T> SerializableComparator<T> byShortFunction(ShortFunction<T> function)

byFunction

public static <T,V> SerializableComparator<T> byFunction(Function<? super T, ? extends V> function,
 Comparator<V> comparator)

Original signature accepted a Comparator which may not be Serializable. This signature is kept for backwards compatibility.

originalByFunction

@Deprecated
public static <T,V> SerializableComparator<T> originalByFunction(Function<? super T, ? extends V> function,
 Comparator<V> comparator)

Deprecated.

Original signature accepted a Comparator which may not be Serializable. This signature is kept for backwards compatibility.

nullSafeEquals

public static boolean nullSafeEquals(Object value1,
 Object value2)

nullSafeCompare

public static <T extends Comparable<T>> int nullSafeCompare(T value1,
 T value2)