Summary: Fields | Methods | Inherited Methods | [Expand All]

public class

Collections

extends Object

java.lang.Object
↳	java.util.Collections

Class Overview

Collections contains static methods which operate on Collection classes.

Summary

Fields
public static final List	EMPTY_LIST	An empty immutable instance of `List`.
public static final Map	EMPTY_MAP	An empty immutable instance of `Map`.
public static final Set	EMPTY_SET	An empty immutable instance of `Set`.

Public Methods
static <T> boolean	addAll(Collection<? super T> c, T... a) Adds all the specified elements to the specified collection.
static <T> Queue<T>	asLifoQueue(Deque<T> deque) Returns a last-in, first-out queue as a view of `deque`.
static <T> int	binarySearch(List<? extends Comparable<? super T>> list, T object) Performs a binary search for the specified element in the specified sorted list.
static <T> int	binarySearch(List<? extends T> list, T object, Comparator<? super T> comparator) Performs a binary search for the specified element in the specified sorted list using the specified comparator.
static <E> Collection<E>	checkedCollection(Collection<E> c, Class<E> type) Returns a dynamically typesafe view of the specified collection.
static <E> List<E>	checkedList(List<E> list, Class<E> type) Returns a dynamically typesafe view of the specified list.
static <K, V> Map<K, V>	checkedMap(Map<K, V> m, Class<K> keyType, Class<V> valueType) Returns a dynamically typesafe view of the specified map.
static <E> Set<E>	checkedSet(Set<E> s, Class<E> type) Returns a dynamically typesafe view of the specified set.
static <K, V> SortedMap<K, V>	checkedSortedMap(SortedMap<K, V> m, Class<K> keyType, Class<V> valueType) Returns a dynamically typesafe view of the specified sorted map.
static <E> SortedSet<E>	checkedSortedSet(SortedSet<E> s, Class<E> type) Returns a dynamically typesafe view of the specified sorted set.
static <T> void	copy(List<? super T> destination, List<? extends T> source) Copies the elements from the source list to the destination list.
static boolean	disjoint(Collection<?> c1, Collection<?> c2) Returns whether the specified collections have no elements in common.
final static <T> List<T>	emptyList() Returns a type-safe empty, immutable `List`.
final static <K, V> Map<K, V>	emptyMap() Returns a type-safe empty, immutable `Map`.
final static <T> Set<T>	emptySet() Returns a type-safe empty, immutable `Set`.
static <T> Enumeration<T>	enumeration(Collection<T> collection) Returns an `Enumeration` on the specified collection.
static <T> void	fill(List<? super T> list, T object) Fills the specified list with the specified element.
static int	frequency(Collection<?> c, Object o) Returns the number of elements in the `Collection` that match the `Object` passed.
static int	indexOfSubList(List<?> list, List<?> sublist) Searches the `list` for `sublist` and returns the beginning index of the first occurrence.
static int	lastIndexOfSubList(List<?> list, List<?> sublist) Searches the `list` for `sublist` and returns the beginning index of the last occurrence.
static <T> ArrayList<T>	list(Enumeration<T> enumeration) Returns an `ArrayList` with all the elements in the `enumeration`.
static <T extends Object & Comparable<? super T>> T	max(Collection<? extends T> collection) Searches the specified collection for the maximum element.
static <T> T	max(Collection<? extends T> collection, Comparator<? super T> comparator) Searches the specified collection for the maximum element using the specified comparator.
static <T> T	min(Collection<? extends T> collection, Comparator<? super T> comparator) Searches the specified collection for the minimum element using the specified comparator.
static <T extends Object & Comparable<? super T>> T	min(Collection<? extends T> collection) Searches the specified collection for the minimum element.
static <T> List<T>	nCopies(int length, T object) Returns a list containing the specified number of the specified element.
static <E> Set<E>	newSetFromMap(Map<E, Boolean> map) Returns a set backed by `map`.
static <T> boolean	replaceAll(List<T> list, T obj, T obj2) Replaces all occurrences of Object `obj` in `list` with `newObj`.
static void	reverse(List<?> list) Modifies the specified `List` by reversing the order of the elements.
static <T> Comparator<T>	reverseOrder() A comparator which reverses the natural order of the elements.
static <T> Comparator<T>	reverseOrder(Comparator<T> c) Returns a `Comparator` that reverses the order of the `Comparator` passed.
static void	rotate(List<?> lst, int dist) Rotates the elements in `list` by the distance `dist` e.g.
static void	shuffle(List<?> list, Random random) Moves every element of the list to a random new position in the list using the specified random number generator.
static void	shuffle(List<?> list) Moves every element of the list to a random new position in the list.
static <E> Set<E>	singleton(E object) Returns a set containing the specified element.
static <E> List<E>	singletonList(E object) Returns a list containing the specified element.
static <K, V> Map<K, V>	singletonMap(K key, V value) Returns a Map containing the specified key and value.
static <T> void	sort(List<T> list, Comparator<? super T> comparator) Sorts the specified list using the specified comparator.
static <T extends Comparable<? super T>> void	sort(List<T> list) Sorts the specified list in ascending natural order.
static void	swap(List<?> list, int index1, int index2) Swaps the elements of list `list` at indices `index1` and `index2`.
static <T> Collection<T>	synchronizedCollection(Collection<T> collection) Returns a wrapper on the specified collection which synchronizes all access to the collection.
static <T> List<T>	synchronizedList(List<T> list) Returns a wrapper on the specified List which synchronizes all access to the List.
static <K, V> Map<K, V>	synchronizedMap(Map<K, V> map) Returns a wrapper on the specified map which synchronizes all access to the map.
static <E> Set<E>	synchronizedSet(Set<E> set) Returns a wrapper on the specified set which synchronizes all access to the set.
static <K, V> SortedMap<K, V>	synchronizedSortedMap(SortedMap<K, V> map) Returns a wrapper on the specified sorted map which synchronizes all access to the sorted map.
static <E> SortedSet<E>	synchronizedSortedSet(SortedSet<E> set) Returns a wrapper on the specified sorted set which synchronizes all access to the sorted set.
static <E> Collection<E>	unmodifiableCollection(Collection<? extends E> collection) Returns a wrapper on the specified collection which throws an `UnsupportedOperationException` whenever an attempt is made to modify the collection.
static <E> List<E>	unmodifiableList(List<? extends E> list) Returns a wrapper on the specified list which throws an `UnsupportedOperationException` whenever an attempt is made to modify the list.
static <K, V> Map<K, V>	unmodifiableMap(Map<? extends K, ? extends V> map) Returns a wrapper on the specified map which throws an `UnsupportedOperationException` whenever an attempt is made to modify the map.
static <E> Set<E>	unmodifiableSet(Set<? extends E> set) Returns a wrapper on the specified set which throws an `UnsupportedOperationException` whenever an attempt is made to modify the set.
static <K, V> SortedMap<K, V>	unmodifiableSortedMap(SortedMap<K, ? extends V> map) Returns a wrapper on the specified sorted map which throws an `UnsupportedOperationException` whenever an attempt is made to modify the sorted map.
static <E> SortedSet<E>	unmodifiableSortedSet(SortedSet<E> set) Returns a wrapper on the specified sorted set which throws an `UnsupportedOperationException` whenever an attempt is made to modify the sorted set.

[Expand]

Inherited Methods

From class java.lang.Object

Object	clone() Creates and returns a copy of this `Object`.
boolean	equals(Object o) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of `Class` that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.
final void	wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait(long millis) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.

Fields

public static final List EMPTY_LIST

Since: API Level 1

An empty immutable instance of List.

public static final Map EMPTY_MAP

Since: API Level 1

An empty immutable instance of Map.

public static final Set EMPTY_SET

Since: API Level 1

An empty immutable instance of Set.

Public Methods

public static boolean addAll (Collection<? super T> c, T... a)

Since: API Level 1

Adds all the specified elements to the specified collection.

Parameters

c	the collection the elements are to be inserted into.
a	the elements to insert.

Returns

true if the collection changed during insertion.

Throws

UnsupportedOperationException	when the method is not supported.
NullPointerException	when `c` or `a` is `null`, or `a` contains one or more `null` elements and `c` doesn't support `null` elements.
IllegalArgumentException	if at least one of the elements can't be inserted into the collection.

public static Queue<T> asLifoQueue (Deque<T> deque)

Since: API Level 9

Returns a last-in, first-out queue as a view of deque.

public static int binarySearch (List<? extends Comparable<? super T>> list, T object)

Since: API Level 1

Performs a binary search for the specified element in the specified sorted list. The list needs to be already sorted in natural sorting order. Searching in an unsorted array has an undefined result. It's also undefined which element is found if there are multiple occurrences of the same element.

Parameters

list	the sorted list to search.
object	the element to find.

Returns

the non-negative index of the element, or a negative index which is the -index - 1 where the element would be inserted

Throws

ClassCastException	if an element in the List or the search element does not implement Comparable, or cannot be compared to each other.

public static int binarySearch (List<? extends T> list, T object, Comparator<? super T> comparator)

Since: API Level 1

Performs a binary search for the specified element in the specified sorted list using the specified comparator. The list needs to be already sorted according to the comparator passed. Searching in an unsorted array has an undefined result. It's also undefined which element is found if there are multiple occurrences of the same element.

Parameters

list	the sorted List to search.
object	the element to find.
comparator	the comparator. If the comparator is `null` then the search uses the objects' natural ordering.

Returns

the non-negative index of the element, or a negative index which is the -index - 1 where the element would be inserted.

Throws

ClassCastException	when an element in the list and the searched element cannot be compared to each other using the comparator.

public static Collection<E> checkedCollection (Collection<E> c, Class<E> type)

Since: API Level 1

Returns a dynamically typesafe view of the specified collection. Trying to insert an element of the wrong type into this collection throws a ClassCastException. At creation time the types in c are not checked for correct type.

Parameters

c	the collection to be wrapped in a typesafe collection.
type	the type of the elements permitted to insert.

Returns

a typesafe collection.

public static List<E> checkedList (List<E> list, Class<E> type)

Since: API Level 1

Returns a dynamically typesafe view of the specified list. Trying to insert an element of the wrong type into this list throws a ClassCastException. At creation time the types in list are not checked for correct type.

Parameters

list	the list to be wrapped in a typesafe list.
type	the type of the elements permitted to insert.

Returns

a typesafe list.

public static Map<K, V> checkedMap (Map<K, V> m, Class<K> keyType, Class<V> valueType)

Since: API Level 1

Returns a dynamically typesafe view of the specified map. Trying to insert an element of the wrong type into this map throws a ClassCastException. At creation time the types in m are not checked for correct type.

Parameters

m	the map to be wrapped in a typesafe map.
keyType	the type of the keys permitted to insert.
valueType	the type of the values permitted to insert.

Returns

a typesafe map.

public static Set<E> checkedSet (Set<E> s, Class<E> type)

Since: API Level 1

Returns a dynamically typesafe view of the specified set. Trying to insert an element of the wrong type into this set throws a ClassCastException. At creation time the types in s are not checked for correct type.

Parameters

s	the set to be wrapped in a typesafe set.
type	the type of the elements permitted to insert.

Returns

a typesafe set.

public static SortedMap<K, V> checkedSortedMap (SortedMap<K, V> m, Class<K> keyType, Class<V> valueType)

Since: API Level 1

Returns a dynamically typesafe view of the specified sorted map. Trying to insert an element of the wrong type into this sorted map throws a ClassCastException. At creation time the types in m are not checked for correct type.

Parameters

m	the sorted map to be wrapped in a typesafe sorted map.
keyType	the type of the keys permitted to insert.
valueType	the type of the values permitted to insert.

Returns

a typesafe sorted map.

public static SortedSet<E> checkedSortedSet (SortedSet<E> s, Class<E> type)

Since: API Level 1

Returns a dynamically typesafe view of the specified sorted set. Trying to insert an element of the wrong type into this sorted set throws a ClassCastException. At creation time the types in s are not checked for correct type.

Parameters

s	the sorted set to be wrapped in a typesafe sorted set.
type	the type of the elements permitted to insert.

Returns

a typesafe sorted set.

public static void copy (List<? super T> destination, List<? extends T> source)

Since: API Level 1

Copies the elements from the source list to the destination list. At the end both lists will have the same objects at the same index. If the destination array is larger than the source list, the elements in the destination list with index >= source.size() will be unchanged.

Parameters

destination	the list whose elements are set from the source list.
source	the list with the elements to be copied into the destination.

Throws

IndexOutOfBoundsException	when the destination list is smaller than the source list.
UnsupportedOperationException	when replacing an element in the destination list is not supported.

public static boolean disjoint (Collection<?> c1, Collection<?> c2)

Since: API Level 1

Returns whether the specified collections have no elements in common.

Parameters

c1	the first collection.
c2	the second collection.

Returns

true if the collections have no elements in common, false otherwise.

Throws

NullPointerException	if one of the collections is `null`.

public static final List<T> emptyList ()

Since: API Level 1

Returns a type-safe empty, immutable List.

Returns

an empty List.

public static final Map<K, V> emptyMap ()

Since: API Level 1

Returns a type-safe empty, immutable Map.

Returns

an empty Map.

public static final Set<T> emptySet ()

Since: API Level 1

Returns a type-safe empty, immutable Set.

Returns

an empty Set.

public static Enumeration<T> enumeration (Collection<T> collection)

Since: API Level 1

Returns an Enumeration on the specified collection.

Parameters

collection	the collection to enumerate.

Returns

an Enumeration.

public static void fill (List<? super T> list, T object)

Since: API Level 1

Fills the specified list with the specified element.

Parameters

list	the list to fill.
object	the element to fill the list with.

Throws

UnsupportedOperationException	when replacing an element in the List is not supported.

public static int frequency (Collection<?> c, Object o)

Since: API Level 1

Returns the number of elements in the Collection that match the Object passed. If the Object is null, then the number of null elements is returned.

Parameters

c	the `Collection` to search.
o	the `Object` to search for.

Returns

the number of matching elements.

Throws

NullPointerException	if the `Collection` parameter is `null`.

public static int indexOfSubList (List<?> list, List<?> sublist)

Since: API Level 1

Searches the list for sublist and returns the beginning index of the first occurrence.

-1 is returned if the sublist does not exist in list.

Parameters

list	the List to search `sublist` in.
sublist	the List to search in `list`.

Returns

the beginning index of the first occurrence of sublist in list, or -1.

public static int lastIndexOfSubList (List<?> list, List<?> sublist)

Since: API Level 1

Searches the list for sublist and returns the beginning index of the last occurrence.

-1 is returned if the sublist does not exist in list.

Parameters

list	the list to search `sublist` in.
sublist	the list to search in `list`.

Returns

the beginning index of the last occurrence of sublist in list, or -1.

public static ArrayList<T> list (Enumeration<T> enumeration)

Since: API Level 1

Returns an ArrayList with all the elements in the enumeration. The elements in the returned ArrayList are in the same order as in the enumeration.

Parameters

enumeration	the source `Enumeration`.

Returns

an ArrayList from enumeration.

public static T max (Collection<? extends T> collection)

Since: API Level 1

Searches the specified collection for the maximum element.

Parameters

collection	the collection to search.

Returns

the maximum element in the Collection.

Throws

ClassCastException	when an element in the collection does not implement `Comparable` or elements cannot be compared to each other.

public static T max (Collection<? extends T> collection, Comparator<? super T> comparator)

Since: API Level 1

Searches the specified collection for the maximum element using the specified comparator.

Parameters

collection	the collection to search.
comparator	the comparator.

Returns

the maximum element in the Collection.

Throws

ClassCastException	when elements in the collection cannot be compared to each other using the `Comparator`.

public static T min (Collection<? extends T> collection, Comparator<? super T> comparator)

Since: API Level 1

Searches the specified collection for the minimum element using the specified comparator.

Parameters

collection	the collection to search.
comparator	the comparator.

Returns

the minimum element in the collection.

Throws

ClassCastException	when elements in the collection cannot be compared to each other using the `Comparator`.

public static T min (Collection<? extends T> collection)

Since: API Level 1

Searches the specified collection for the minimum element.

Parameters

collection	the collection to search.

Returns

the minimum element in the collection.

Throws

ClassCastException	when an element in the collection does not implement `Comparable` or elements cannot be compared to each other.

public static List<T> nCopies (int length, T object)

Since: API Level 1

Returns a list containing the specified number of the specified element. The list cannot be modified. The list is serializable.

Parameters

length	the size of the returned list.
object	the element to be added `length` times to a list.

Returns

a list containing length copies of the element.

Throws

IllegalArgumentException	when `length < 0`.

public static Set<E> newSetFromMap (Map<E, Boolean> map)

Since: API Level 9

Returns a set backed by map.

Throws

IllegalArgumentException	if the map is not empty

public static boolean replaceAll (List<T> list, T obj, T obj2)

Since: API Level 1

Replaces all occurrences of Object obj in list with newObj. If the obj is null, then all occurrences of null are replaced with newObj.

Parameters

list	the list to modify.
obj	the object to find and replace occurrences of.
obj2	the object to replace all occurrences of `obj` in `list`.

Returns

true, if at least one occurrence of obj has been found in list.

Throws

UnsupportedOperationException	if the list does not support setting elements.

public static void reverse (List<?> list)

Since: API Level 1

Modifies the specified List by reversing the order of the elements.

Parameters

list	the list to reverse.

Throws

UnsupportedOperationException	when replacing an element in the List is not supported.

public static Comparator<T> reverseOrder ()

Since: API Level 1

A comparator which reverses the natural order of the elements. The Comparator that's returned is Serializable.

Returns

a Comparator instance.

public static Comparator<T> reverseOrder (Comparator<T> c)

Since: API Level 1

Returns a Comparator that reverses the order of the Comparator passed. If the Comparator passed is null, then this method is equivalent to reverseOrder().

The Comparator that's returned is Serializable if the Comparator passed is serializable or null.

Parameters

c	the `Comparator` to reverse or `null`.

Returns

a Comparator instance.

public static void rotate (List<?> lst, int dist)

Since: API Level 1

Rotates the elements in list by the distance dist

e.g. for a given list with elements [1, 2, 3, 4, 5, 6, 7, 8, 9, 0], calling rotate(list, 3) or rotate(list, -7) would modify the list to look like this: [8, 9, 0, 1, 2, 3, 4, 5, 6, 7]

Parameters

lst	the list whose elements are to be rotated.
dist	is the distance the list is rotated. This can be any valid integer. Negative values rotate the list backwards.

public static void shuffle (List<?> list, Random random)

Since: API Level 1

Moves every element of the list to a random new position in the list using the specified random number generator.

Parameters

list	the list to shuffle.
random	the random number generator.

Throws

UnsupportedOperationException	when replacing an element in the list is not supported.

public static void shuffle (List<?> list)

Since: API Level 1

Moves every element of the list to a random new position in the list.

Parameters

list	the List to shuffle.

Throws

UnsupportedOperationException	when replacing an element in the List is not supported.

public static Set<E> singleton (E object)

Since: API Level 1

Returns a set containing the specified element. The set cannot be modified. The set is serializable.

Parameters

object	the element.

Returns

a set containing the element.

public static List<E> singletonList (E object)

Since: API Level 1

Returns a list containing the specified element. The list cannot be modified. The list is serializable.

Parameters

object	the element.

Returns

a list containing the element.

public static Map<K, V> singletonMap (K key, V value)

Since: API Level 1

Returns a Map containing the specified key and value. The map cannot be modified. The map is serializable.

Parameters

key	the key.
value	the value.

Returns

a Map containing the key and value.

public static void sort (List<T> list, Comparator<? super T> comparator)

Since: API Level 1

Sorts the specified list using the specified comparator. The algorithm is stable which means equal elements don't get reordered.

Parameters

list	the list to be sorted.
comparator	the comparator.

Throws

ClassCastException	when elements in the list cannot be compared to each other using the comparator.

public static void sort (List<T> list)

Since: API Level 1

Sorts the specified list in ascending natural order. The algorithm is stable which means equal elements don't get reordered.

Parameters

list	the list to be sorted.

Throws

ClassCastException	when an element in the List does not implement Comparable or elements cannot be compared to each other.

public static void swap (List<?> list, int index1, int index2)

Since: API Level 1

Swaps the elements of list list at indices index1 and index2.

Parameters

list	the list to manipulate.
index1	position of the first element to swap with the element in index2.
index2	position of the other element.

Throws

IndexOutOfBoundsException	if index1 or index2 is out of range of this list.

public static Collection<T> synchronizedCollection (Collection<T> collection)

Since: API Level 1

Returns a wrapper on the specified collection which synchronizes all access to the collection.

Parameters

collection	the Collection to wrap in a synchronized collection.

Returns

a synchronized Collection.

public static List<T> synchronizedList (List<T> list)

Since: API Level 1

Returns a wrapper on the specified List which synchronizes all access to the List.

Parameters

list	the List to wrap in a synchronized list.

Returns

a synchronized List.

public static Map<K, V> synchronizedMap (Map<K, V> map)

Since: API Level 1

Returns a wrapper on the specified map which synchronizes all access to the map.

Parameters

map	the map to wrap in a synchronized map.

Returns

a synchronized Map.

public static Set<E> synchronizedSet (Set<E> set)

Since: API Level 1

Returns a wrapper on the specified set which synchronizes all access to the set.

Parameters

set	the set to wrap in a synchronized set.

Returns

a synchronized set.

public static SortedMap<K, V> synchronizedSortedMap (SortedMap<K, V> map)

Since: API Level 1

Returns a wrapper on the specified sorted map which synchronizes all access to the sorted map.

Parameters

map	the sorted map to wrap in a synchronized sorted map.

Returns

a synchronized sorted map.

public static SortedSet<E> synchronizedSortedSet (SortedSet<E> set)

Since: API Level 1

Returns a wrapper on the specified sorted set which synchronizes all access to the sorted set.

Parameters

set	the sorted set to wrap in a synchronized sorted set.

Returns

a synchronized sorted set.

public static Collection<E> unmodifiableCollection (Collection<? extends E> collection)

Since: API Level 1

Returns a wrapper on the specified collection which throws an UnsupportedOperationException whenever an attempt is made to modify the collection.

Parameters

collection	the collection to wrap in an unmodifiable collection.

Returns

an unmodifiable collection.

public static List<E> unmodifiableList (List<? extends E> list)

Since: API Level 1

Returns a wrapper on the specified list which throws an UnsupportedOperationException whenever an attempt is made to modify the list.

Parameters

list	the list to wrap in an unmodifiable list.

Returns

an unmodifiable List.

public static Map<K, V> unmodifiableMap (Map<? extends K, ? extends V> map)

Since: API Level 1

Returns a wrapper on the specified map which throws an UnsupportedOperationException whenever an attempt is made to modify the map.

Parameters

map	the map to wrap in an unmodifiable map.

Returns

a unmodifiable map.

public static Set<E> unmodifiableSet (Set<? extends E> set)

Since: API Level 1

Returns a wrapper on the specified set which throws an UnsupportedOperationException whenever an attempt is made to modify the set.

Parameters

set	the set to wrap in an unmodifiable set.

Returns

a unmodifiable set

public static SortedMap<K, V> unmodifiableSortedMap (SortedMap<K, ? extends V> map)

Since: API Level 1

Returns a wrapper on the specified sorted map which throws an UnsupportedOperationException whenever an attempt is made to modify the sorted map.

Parameters

map	the sorted map to wrap in an unmodifiable sorted map.

Returns

a unmodifiable sorted map

public static SortedSet<E> unmodifiableSortedSet (SortedSet<E> set)

Since: API Level 1

Returns a wrapper on the specified sorted set which throws an UnsupportedOperationException whenever an attempt is made to modify the sorted set.

Parameters

set	the sorted set to wrap in an unmodifiable sorted set.

Returns

a unmodifiable sorted set.

Interfaces

Classes

Enums

Exceptions

Errors

Collections

Class Overview

Summary

Fields

public static final List EMPTY_LIST

public static final Map EMPTY_MAP

public static final Set EMPTY_SET

Public Methods

public static boolean addAll (Collection<? super T> c, T... a)

Parameters

Returns

Throws

public static Queue<T> asLifoQueue (Deque<T> deque)

public static int binarySearch (List<? extends Comparable<? super T>> list, T object)

Parameters

Returns

Throws

public static int binarySearch (List<? extends T> list, T object, Comparator<? super T> comparator)

Parameters

Returns

Throws

public static Collection<E> checkedCollection (Collection<E> c, Class<E> type)

Parameters

Returns

public static List<E> checkedList (List<E> list, Class<E> type)

Parameters

Returns

public static Map<K, V> checkedMap (Map<K, V> m, Class<K> keyType, Class<V> valueType)

Parameters

Returns

public static Set<E> checkedSet (Set<E> s, Class<E> type)

Parameters

Returns

public static SortedMap<K, V> checkedSortedMap (SortedMap<K, V> m, Class<K> keyType, Class<V> valueType)

Parameters

Returns

public static SortedSet<E> checkedSortedSet (SortedSet<E> s, Class<E> type)

Parameters

Returns

public static void copy (List<? super T> destination, List<? extends T> source)

Parameters

Throws

public static boolean disjoint (Collection<?> c1, Collection<?> c2)

Parameters

Returns

Throws

public static final List<T> emptyList ()

Returns

See Also

public static final Map<K, V> emptyMap ()

Returns

See Also

public static final Set<T> emptySet ()

Returns

See Also

public static Enumeration<T> enumeration (Collection<T> collection)

Parameters

Returns

public static void fill (List<? super T> list, T object)

Parameters

Throws

public static int frequency (Collection<?> c, Object o)

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Returns

Throws

public static int indexOfSubList (List<?> list, List<?> sublist)

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Returns

public static int lastIndexOfSubList (List<?> list, List<?> sublist)

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Returns

public static ArrayList<T> list (Enumeration<T> enumeration)

Parameters

Returns

public static T max (Collection<? extends T> collection)