Package io.deephaven.datastructures.util

Class CollectionUtil

java.lang.Object

io.deephaven.datastructures.util.CollectionUtil

public class CollectionUtil
extends Object

Utility methods for creating collections.

Field Summary

Fields

Modifier and Type	Field	Description
static final Set	UNIVERSAL_SET	The universal set (immutable).
static final byte[]	ZERO_LENGTH_BYTE_ARRAY
static final double[]	ZERO_LENGTH_DOUBLE_ARRAY
static final double[][]	ZERO_LENGTH_DOUBLE_ARRAY_ARRAY
static final float[]	ZERO_LENGTH_FLOAT_ARRAY
static final int[]	ZERO_LENGTH_INT_ARRAY
static final int[][]	ZERO_LENGTH_INT_ARRAY_ARRAY
static final long[]	ZERO_LENGTH_LONG_ARRAY
static final Object[]	ZERO_LENGTH_OBJECT_ARRAY
static final short[]	ZERO_LENGTH_SHORT_ARRAY
static final String[]	ZERO_LENGTH_STRING_ARRAY
static final String[][]	ZERO_LENGTH_STRING_ARRAY_ARRAY

Constructor Summary

Constructors

Constructor	Description
CollectionUtil()

Method Summary

Modifier and Type	Method	Description
static <E> boolean	containsNull(E[] elems)	Determines if an array contains a null.
static double[]	convertDoublesToPrimitiveArray(Collection<Double> collection)	Converts a List of Doubles to an array of doubles.
static int[]	convertIntegersToPrimitiveArray(Collection<Integer> collection)	Converts a Collection of Integers to an array of ints.
static long[]	convertLongsToPrimitiveArray(Collection<Long> collection)	Converts a Collection of Integers to an array of ints.
static <K, V> Map<K,V>	invertMap(Map<V,K> sourceMap)
static <E> List<E>	listFromArray(E... data)
static <K, V> Map<K,V>	mapFromArray(Class<K> typeK, Class<V> typeV, boolean allowDuplicateKeys, Object... data)
static <K, V> Map<K,V>	mapFromArray(Class<K> typeK, Class<V> typeV, Object... data)
static <K, V> Map<K,V>	newSizedHashMap(int nEntries)	Returns an empty HashMap with a big enough capacity such that the given number of entries can be added without resizing.
static <E> Set<E>	newSizedHashSet(int nEntries)	Returns an empty HashSet with a big enough capacity such that the given number of entries can be added without resizing.
static <K, V> Map<K,V>	newSizedLinkedHashMap(int nEntries)	Returns an empty LinkedHashMap with a big enough capacity such that the given number of entries can be added without resizing.
static <E> Set<E>	newSizedLinkedHashSet(int nEntries)	Returns an empty LinkedHashSet with a big enough capacity such that the given number of entries can be added without resizing.
static <TYPE> Set<TYPE>	setFromArray(@NotNull Class<TYPE> type, @NotNull Object... data)
static <E> Set<E>	setFromArray(E... data)
static <E> void	shuffle(E[] elems, Random random)	Shuffles the elements in an array.
static <T> Set<T>	universalSet()	Returns the universal set (immutable).
static <K, V> Map<K,V>	unmodifiableInvertMap(Map<V,K> sourceMap)
static <K, V> Map<K,V>	unmodifiableMapFromArray(Class<K> typeK, Class<V> typeV, Object... data)
static <E> Set<E>	unmodifiableSetFromArray(E... data)

Methods inherited from class java.lang.Object

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

Field Details

ZERO_LENGTH_BYTE_ARRAY

public static final byte[] ZERO_LENGTH_BYTE_ARRAY

ZERO_LENGTH_SHORT_ARRAY

public static final short[] ZERO_LENGTH_SHORT_ARRAY

ZERO_LENGTH_INT_ARRAY

public static final int[] ZERO_LENGTH_INT_ARRAY

ZERO_LENGTH_INT_ARRAY_ARRAY

public static final int[][] ZERO_LENGTH_INT_ARRAY_ARRAY

ZERO_LENGTH_LONG_ARRAY

public static final long[] ZERO_LENGTH_LONG_ARRAY

ZERO_LENGTH_FLOAT_ARRAY

public static final float[] ZERO_LENGTH_FLOAT_ARRAY

ZERO_LENGTH_DOUBLE_ARRAY

public static final double[] ZERO_LENGTH_DOUBLE_ARRAY

ZERO_LENGTH_DOUBLE_ARRAY_ARRAY

public static final double[][] ZERO_LENGTH_DOUBLE_ARRAY_ARRAY

ZERO_LENGTH_OBJECT_ARRAY

public static final Object[] ZERO_LENGTH_OBJECT_ARRAY

ZERO_LENGTH_STRING_ARRAY

public static final String[] ZERO_LENGTH_STRING_ARRAY

ZERO_LENGTH_STRING_ARRAY_ARRAY

public static final String[][] ZERO_LENGTH_STRING_ARRAY_ARRAY

UNIVERSAL_SET

public static final Set UNIVERSAL_SET

The universal set (immutable). This set is serializable.

Constructor Details

CollectionUtil

public CollectionUtil()

Method Details

unmodifiableMapFromArray

public static <K,
V> Map<K,V> unmodifiableMapFromArray(Class<K> typeK,
 Class<V> typeV,
 Object... data)

unmodifiableInvertMap

public static <K,
V> Map<K,V> unmodifiableInvertMap(Map<V,K> sourceMap)

unmodifiableSetFromArray

public static <E> Set<E> unmodifiableSetFromArray(E... data)

mapFromArray

public static <K,
V> Map<K,V> mapFromArray(Class<K> typeK,
 Class<V> typeV,
 Object... data)

mapFromArray

public static <K,
V> Map<K,V> mapFromArray(Class<K> typeK,
 Class<V> typeV,
 boolean allowDuplicateKeys,
 Object... data)

invertMap

public static <K,
V> Map<K,V> invertMap(Map<V,K> sourceMap)

setFromArray

public static <E> Set<E> setFromArray(E... data)

setFromArray

public static <TYPE> Set<TYPE> setFromArray(@NotNull
 @NotNull Class<TYPE> type,
 @NotNull
 @NotNull Object... data)

listFromArray

public static <E> List<E> listFromArray(E... data)

newSizedHashMap

public static <K,
V> Map<K,V> newSizedHashMap(int nEntries)

Returns an empty HashMap with a big enough capacity such that the given number of entries can be added without resizing.

newSizedLinkedHashMap

public static <K,
V> Map<K,V> newSizedLinkedHashMap(int nEntries)

Returns an empty LinkedHashMap with a big enough capacity such that the given number of entries can be added without resizing.

newSizedHashSet

public static <E> Set<E> newSizedHashSet(int nEntries)

Returns an empty HashSet with a big enough capacity such that the given number of entries can be added without resizing.

newSizedLinkedHashSet

public static <E> Set<E> newSizedLinkedHashSet(int nEntries)

Returns an empty LinkedHashSet with a big enough capacity such that the given number of entries can be added without resizing.

convertDoublesToPrimitiveArray

public static double[] convertDoublesToPrimitiveArray(Collection<Double> collection)

Converts a List of Doubles to an array of doubles.

convertIntegersToPrimitiveArray

public static int[] convertIntegersToPrimitiveArray(Collection<Integer> collection)

Converts a Collection of Integers to an array of ints.

convertLongsToPrimitiveArray

public static long[] convertLongsToPrimitiveArray(Collection<Long> collection)

Converts a Collection of Integers to an array of ints.

shuffle

public static <E> void shuffle(E[] elems,
 Random random)

Shuffles the elements in an array.

containsNull

public static <E> boolean containsNull(E[] elems)

Determines if an array contains a null.

universalSet

public static <T> Set<T> universalSet()

Returns the universal set (immutable). This set is serializable.