Interface List<E>
- Type Parameters:
-
E
- the type of elements in this list
- All Superinterfaces:
-
Collection<E>
,Iterable<E>
- All Known Implementing Classes:
-
AbstractList
,AbstractSequentialList
,ArrayList
,AttributeList
,CopyOnWriteArrayList
,LinkedList
,RoleList
,RoleUnresolvedList
,Stack
,Vector
public interface List<E> extends Collection<E>
Unlike sets, lists typically allow duplicate elements. More formally, lists typically allow pairs of elements e1
and e2
such that e1.equals(e2)
, and they typically allow multiple null elements if they allow null elements at all. It is not inconceivable that someone might wish to implement a list that prohibits duplicates, by throwing runtime exceptions when the user attempts to insert them, but we expect this usage to be rare.
The List
interface places additional stipulations, beyond those specified in the Collection
interface, on the contracts of the iterator
, add
, remove
, equals
, and hashCode
methods. Declarations for other inherited methods are also included here for convenience.
The List
interface provides four methods for positional (indexed) access to list elements. Lists (like Java arrays) are zero based. Note that these operations may execute in time proportional to the index value for some implementations (the LinkedList
class, for example). Thus, iterating over the elements in a list is typically preferable to indexing through it if the caller does not know the implementation.
The List
interface provides a special iterator, called a ListIterator
, that allows element insertion and replacement, and bidirectional access in addition to the normal operations that the Iterator
interface provides. A method is provided to obtain a list iterator that starts at a specified position in the list.
The List
interface provides two methods to search for a specified object. From a performance standpoint, these methods should be used with caution. In many implementations they will perform costly linear searches.
The List
interface provides two methods to efficiently insert and remove multiple elements at an arbitrary point in the list.
Note: While it is permissible for lists to contain themselves as elements, extreme caution is advised: the equals
and hashCode
methods are no longer well defined on such a list.
Some list implementations have restrictions on the elements that they may contain. For example, some implementations prohibit null elements, and some have restrictions on the types of their elements. Attempting to add an ineligible element throws an unchecked exception, typically NullPointerException
or ClassCastException
. Attempting to query the presence of an ineligible element may throw an exception, or it may simply return false; some implementations will exhibit the former behavior and some will exhibit the latter. More generally, attempting an operation on an ineligible element whose completion would not result in the insertion of an ineligible element into the list may throw an exception or it may succeed, at the option of the implementation. Such exceptions are marked as "optional" in the specification for this interface.
Unmodifiable Lists
The List.of
and List.copyOf
static factory methods provide a convenient way to create unmodifiable lists. The List
instances created by these methods have the following characteristics:
- They are unmodifiable. Elements cannot be added, removed, or replaced. Calling any mutator method on the List will always cause
UnsupportedOperationException
to be thrown. However, if the contained elements are themselves mutable, this may cause the List's contents to appear to change. - They disallow
null
elements. Attempts to create them withnull
elements result inNullPointerException
. - They are serializable if all elements are serializable.
- The order of elements in the list is the same as the order of the provided arguments, or of the elements in the provided array.
- The lists and their
subList
views implement theRandomAccess
interface. - They are value-based. Programmers should treat instances that are equal as interchangeable and should not use them for synchronization, or unpredictable behavior may occur. For example, in a future release, synchronization may fail. Callers should make no assumptions about the identity of the returned instances. Factories are free to create new instances or reuse existing ones.
- They are serialized as specified on the Serialized Form page.
This interface is a member of the Java Collections Framework.
Method Summary
Modifier and Type | Method | Description |
---|---|---|
void |
add |
Inserts the specified element at the specified position in this list (optional operation). |
boolean |
add |
Appends the specified element to the end of this list (optional operation). |
boolean |
addAll |
Inserts all of the elements in the specified collection into this list at the specified position (optional operation). |
boolean |
addAll |
Appends all of the elements in the specified collection to the end of this list, in the order that they are returned by the specified collection's iterator (optional operation). |
void |
clear() |
Removes all of the elements from this list (optional operation). |
boolean |
contains |
Returns true if this list contains the specified element. |
boolean |
containsAll |
Returns true if this list contains all of the elements of the specified collection. |
static <E> List<E> |
copyOf |
Returns an unmodifiable List containing the elements of the given Collection, in its iteration order. |
boolean |
equals |
Compares the specified object with this list for equality. |
E |
get |
Returns the element at the specified position in this list. |
int |
hashCode() |
Returns the hash code value for this list. |
int |
indexOf |
Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element. |
boolean |
isEmpty() |
Returns true if this list contains no elements. |
Iterator<E> |
iterator() |
Returns an iterator over the elements in this list in proper sequence. |
int |
lastIndexOf |
Returns the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element. |
ListIterator<E> |
listIterator() |
Returns a list iterator over the elements in this list (in proper sequence). |
ListIterator<E> |
listIterator |
Returns a list iterator over the elements in this list (in proper sequence), starting at the specified position in the list. |
static <E> List<E> |
of() |
Returns an unmodifiable list containing zero elements. |
static <E> List<E> |
of |
Returns an unmodifiable list containing one element. |
static <E> List<E> |
of |
Returns an unmodifiable list containing an arbitrary number of elements. |
static <E> List<E> |
of |
Returns an unmodifiable list containing two elements. |
static <E> List<E> |
of |
Returns an unmodifiable list containing three elements. |
static <E> List<E> |
of |
Returns an unmodifiable list containing four elements. |
static <E> List<E> |
of |
Returns an unmodifiable list containing five elements. |
static <E> List<E> |
of |
Returns an unmodifiable list containing six elements. |
static <E> List<E> |
of |
Returns an unmodifiable list containing seven elements. |
static <E> List<E> |
of |
Returns an unmodifiable list containing eight elements. |
static <E> List<E> |
of |
Returns an unmodifiable list containing nine elements. |
static <E> List<E> |
of |
Returns an unmodifiable list containing ten elements. |
E |
remove |
Removes the element at the specified position in this list (optional operation). |
boolean |
remove |
Removes the first occurrence of the specified element from this list, if it is present (optional operation). |
boolean |
removeAll |
Removes from this list all of its elements that are contained in the specified collection (optional operation). |
default void |
replaceAll |
Replaces each element of this list with the result of applying the operator to that element. |
boolean |
retainAll |
Retains only the elements in this list that are contained in the specified collection (optional operation). |
E |
set |
Replaces the element at the specified position in this list with the specified element (optional operation). |
int |
size() |
Returns the number of elements in this list. |
default void |
sort |
Sorts this list according to the order induced by the specified Comparator . |
default Spliterator<E> |
spliterator() |
Creates a Spliterator over the elements in this list. |
List<E> |
subList |
Returns a view of the portion of this list between the specified fromIndex , inclusive, and toIndex , exclusive. |
Object[] |
toArray() |
Returns an array containing all of the elements in this list in proper sequence (from first to last element). |
<T> T[] |
toArray |
Returns an array containing all of the elements in this list in proper sequence (from first to last element); the runtime type of the returned array is that of the specified array. |
Methods declared in interface java.util.Collection
parallelStream, removeIf, stream, toArray
Method Details
size
int size()
Integer.MAX_VALUE
elements, returns Integer.MAX_VALUE
.- Specified by:
-
size
in interfaceCollection<E>
- Returns:
- the number of elements in this list
isEmpty
boolean isEmpty()
true
if this list contains no elements.- Specified by:
-
isEmpty
in interfaceCollection<E>
- Returns:
-
true
if this list contains no elements
contains
boolean contains(Object o)
true
if this list contains the specified element. More formally, returns true
if and only if this list contains at least one element e
such that Objects.equals(o, e)
.- Specified by:
-
contains
in interfaceCollection<E>
- Parameters:
-
o
- element whose presence in this list is to be tested - Returns:
-
true
if this list contains the specified element - Throws:
-
ClassCastException
- if the type of the specified element is incompatible with this list (optional) -
NullPointerException
- if the specified element is null and this list does not permit null elements (optional)
iterator
Iterator<E> iterator()
toArray
Object[] toArray()
The returned array will be "safe" in that no references to it are maintained by this list. (In other words, this method must allocate a new array even if this list is backed by an array). The caller is thus free to modify the returned array.
This method acts as bridge between array-based and collection-based APIs.
- Specified by:
-
toArray
in interfaceCollection<E>
- Returns:
- an array containing all of the elements in this list in proper sequence
- See Also:
toArray
<T> T[] toArray(T[] a)
If the list fits in the specified array with room to spare (i.e., the array has more elements than the list), the element in the array immediately following the end of the list is set to null
. (This is useful in determining the length of the list only if the caller knows that the list does not contain any null elements.)
Like the toArray()
method, this method acts as bridge between array-based and collection-based APIs. Further, this method allows precise control over the runtime type of the output array, and may, under certain circumstances, be used to save allocation costs.
Suppose x
is a list known to contain only strings. The following code can be used to dump the list into a newly allocated array of String
:
String[] y = x.toArray(new String[0]);
Note that toArray(new Object[0])
is identical in function to toArray()
.- Specified by:
-
toArray
in interfaceCollection<E>
- Type Parameters:
-
T
- the component type of the array to contain the collection - Parameters:
-
a
- the array into which the elements of this list are to be stored, if it is big enough; otherwise, a new array of the same runtime type is allocated for this purpose. - Returns:
- an array containing the elements of this list
- Throws:
-
ArrayStoreException
- if the runtime type of the specified array is not a supertype of the runtime type of every element in this list -
NullPointerException
- if the specified array is null
add
boolean add(E e)
Lists that support this operation may place limitations on what elements may be added to this list. In particular, some lists will refuse to add null elements, and others will impose restrictions on the type of elements that may be added. List classes should clearly specify in their documentation any restrictions on what elements may be added.
- Specified by:
-
add
in interfaceCollection<E>
- Parameters:
-
e
- element to be appended to this list - Returns:
-
true
(as specified byCollection.add(E)
) - Throws:
-
UnsupportedOperationException
- if theadd
operation is not supported by this list -
ClassCastException
- if the class of the specified element prevents it from being added to this list -
NullPointerException
- if the specified element is null and this list does not permit null elements -
IllegalArgumentException
- if some property of this element prevents it from being added to this list
remove
boolean remove(Object o)
i
such that Objects.equals(o, get(i))
(if such an element exists). Returns true
if this list contained the specified element (or equivalently, if this list changed as a result of the call).- Specified by:
-
remove
in interfaceCollection<E>
- Parameters:
-
o
- element to be removed from this list, if present - Returns:
-
true
if this list contained the specified element - Throws:
-
ClassCastException
- if the type of the specified element is incompatible with this list (optional) -
NullPointerException
- if the specified element is null and this list does not permit null elements (optional) -
UnsupportedOperationException
- if theremove
operation is not supported by this list
containsAll
boolean containsAll(Collection<?> c)
true
if this list contains all of the elements of the specified collection.- Specified by:
-
containsAll
in interfaceCollection<E>
- Parameters:
-
c
- collection to be checked for containment in this list - Returns:
-
true
if this list contains all of the elements of the specified collection - Throws:
-
ClassCastException
- if the types of one or more elements in the specified collection are incompatible with this list (optional) -
NullPointerException
- if the specified collection contains one or more null elements and this list does not permit null elements (optional), or if the specified collection is null - See Also:
addAll
boolean addAll(Collection<? extends E> c)
- Specified by:
-
addAll
in interfaceCollection<E>
- Parameters:
-
c
- collection containing elements to be added to this list - Returns:
-
true
if this list changed as a result of the call - Throws:
-
UnsupportedOperationException
- if theaddAll
operation is not supported by this list -
ClassCastException
- if the class of an element of the specified collection prevents it from being added to this list -
NullPointerException
- if the specified collection contains one or more null elements and this list does not permit null elements, or if the specified collection is null -
IllegalArgumentException
- if some property of an element of the specified collection prevents it from being added to this list - See Also:
addAll
boolean addAll(int index, Collection<? extends E> c)
- Parameters:
-
index
- index at which to insert the first element from the specified collection -
c
- collection containing elements to be added to this list - Returns:
-
true
if this list changed as a result of the call - Throws:
-
UnsupportedOperationException
- if theaddAll
operation is not supported by this list -
ClassCastException
- if the class of an element of the specified collection prevents it from being added to this list -
NullPointerException
- if the specified collection contains one or more null elements and this list does not permit null elements, or if the specified collection is null -
IllegalArgumentException
- if some property of an element of the specified collection prevents it from being added to this list -
IndexOutOfBoundsException
- if the index is out of range (index < 0 || index > size()
)
removeAll
boolean removeAll(Collection<?> c)
- Specified by:
-
removeAll
in interfaceCollection<E>
- Parameters:
-
c
- collection containing elements to be removed from this list - Returns:
-
true
if this list changed as a result of the call - Throws:
-
UnsupportedOperationException
- if theremoveAll
operation is not supported by this list -
ClassCastException
- if the class of an element of this list is incompatible with the specified collection (optional) -
NullPointerException
- if this list contains a null element and the specified collection does not permit null elements (optional), or if the specified collection is null - See Also:
retainAll
boolean retainAll(Collection<?> c)
- Specified by:
-
retainAll
in interfaceCollection<E>
- Parameters:
-
c
- collection containing elements to be retained in this list - Returns:
-
true
if this list changed as a result of the call - Throws:
-
UnsupportedOperationException
- if theretainAll
operation is not supported by this list -
ClassCastException
- if the class of an element of this list is incompatible with the specified collection (optional) -
NullPointerException
- if this list contains a null element and the specified collection does not permit null elements (optional), or if the specified collection is null - See Also:
replaceAll
default void replaceAll(UnaryOperator<E> operator)
- Implementation Requirements:
- The default implementation is equivalent to, for this
list
:
If the list's list-iterator does not support thefinal ListIterator<E> li = list.listIterator(); while (li.hasNext()) { li.set(operator.apply(li.next())); }
set
operation then anUnsupportedOperationException
will be thrown when replacing the first element. - Parameters:
-
operator
- the operator to apply to each element - Throws:
-
UnsupportedOperationException
- if this list is unmodifiable. Implementations may throw this exception if an element cannot be replaced or if, in general, modification is not supported -
NullPointerException
- if the specified operator is null or if the operator result is a null value and this list does not permit null elements (optional) - Since:
- 1.8
sort
default void sort(Comparator<? super E> c)
Comparator
. The sort is stable: this method must not reorder equal elements. All elements in this list must be mutually comparable using the specified comparator (that is, c.compare(e1, e2)
must not throw a ClassCastException
for any elements e1
and e2
in the list).
If the specified comparator is null
then all elements in this list must implement the Comparable
interface and the elements' natural ordering should be used.
This list must be modifiable, but need not be resizable.
- Implementation Requirements:
- The default implementation obtains an array containing all elements in this list, sorts the array, and iterates over this list resetting each element from the corresponding position in the array. (This avoids the n2 log(n) performance that would result from attempting to sort a linked list in place.)
- Implementation Note:
- This implementation is a stable, adaptive, iterative mergesort that requires far fewer than n lg(n) comparisons when the input array is partially sorted, while offering the performance of a traditional mergesort when the input array is randomly ordered. If the input array is nearly sorted, the implementation requires approximately n comparisons. Temporary storage requirements vary from a small constant for nearly sorted input arrays to n/2 object references for randomly ordered input arrays.
The implementation takes equal advantage of ascending and descending order in its input array, and can take advantage of ascending and descending order in different parts of the same input array. It is well-suited to merging two or more sorted arrays: simply concatenate the arrays and sort the resulting array.
The implementation was adapted from Tim Peters's list sort for Python ( TimSort). It uses techniques from Peter McIlroy's "Optimistic Sorting and Information Theoretic Complexity", in Proceedings of the Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, pp 467-474, January 1993.
- Parameters:
-
c
- theComparator
used to compare list elements. Anull
value indicates that the elements' natural ordering should be used - Throws:
-
ClassCastException
- if the list contains elements that are not mutually comparable using the specified comparator -
UnsupportedOperationException
- if the list's list-iterator does not support theset
operation -
IllegalArgumentException
- (optional) if the comparator is found to violate theComparator
contract - Since:
- 1.8
clear
void clear()
- Specified by:
-
clear
in interfaceCollection<E>
- Throws:
-
UnsupportedOperationException
- if theclear
operation is not supported by this list
equals
boolean equals(Object o)
true
if and only if the specified object is also a list, both lists have the same size, and all corresponding pairs of elements in the two lists are equal. (Two elements e1
and e2
are equal if Objects.equals(e1, e2)
.) In other words, two lists are defined to be equal if they contain the same elements in the same order. This definition ensures that the equals method works properly across different implementations of the List
interface.- Specified by:
-
equals
in interfaceCollection<E>
- Overrides:
-
equals
in classObject
- Parameters:
-
o
- the object to be compared for equality with this list - Returns:
-
true
if the specified object is equal to this list - See Also:
hashCode
int hashCode()
int hashCode = 1;
for (E e : list)
hashCode = 31*hashCode + (e==null ? 0 : e.hashCode());
This ensures that list1.equals(list2)
implies that list1.hashCode()==list2.hashCode()
for any two lists, list1
and list2
, as required by the general contract of Object.hashCode()
.- Specified by:
-
hashCode
in interfaceCollection<E>
- Overrides:
-
hashCode
in classObject
- Returns:
- the hash code value for this list
- See Also:
get
E get(int index)
- Parameters:
-
index
- index of the element to return - Returns:
- the element at the specified position in this list
- Throws:
-
IndexOutOfBoundsException
- if the index is out of range (index < 0 || index >= size()
)
set
E set(int index, E element)
- Parameters:
-
index
- index of the element to replace -
element
- element to be stored at the specified position - Returns:
- the element previously at the specified position
- Throws:
-
UnsupportedOperationException
- if theset
operation is not supported by this list -
ClassCastException
- if the class of the specified element prevents it from being added to this list -
NullPointerException
- if the specified element is null and this list does not permit null elements -
IllegalArgumentException
- if some property of the specified element prevents it from being added to this list -
IndexOutOfBoundsException
- if the index is out of range (index < 0 || index >= size()
)
add
void add(int index, E element)
- Parameters:
-
index
- index at which the specified element is to be inserted -
element
- element to be inserted - Throws:
-
UnsupportedOperationException
- if theadd
operation is not supported by this list -
ClassCastException
- if the class of the specified element prevents it from being added to this list -
NullPointerException
- if the specified element is null and this list does not permit null elements -
IllegalArgumentException
- if some property of the specified element prevents it from being added to this list -
IndexOutOfBoundsException
- if the index is out of range (index < 0 || index > size()
)
remove
E remove(int index)
- Parameters:
-
index
- the index of the element to be removed - Returns:
- the element previously at the specified position
- Throws:
-
UnsupportedOperationException
- if theremove
operation is not supported by this list -
IndexOutOfBoundsException
- if the index is out of range (index < 0 || index >= size()
)
indexOf
int indexOf(Object o)
i
such that Objects.equals(o, get(i))
, or -1 if there is no such index.- Parameters:
-
o
- element to search for - Returns:
- the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element
- Throws:
-
ClassCastException
- if the type of the specified element is incompatible with this list (optional) -
NullPointerException
- if the specified element is null and this list does not permit null elements (optional)
lastIndexOf
int lastIndexOf(Object o)
i
such that Objects.equals(o, get(i))
, or -1 if there is no such index.- Parameters:
-
o
- element to search for - Returns:
- the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element
- Throws:
-
ClassCastException
- if the type of the specified element is incompatible with this list (optional) -
NullPointerException
- if the specified element is null and this list does not permit null elements (optional)
listIterator
ListIterator<E> listIterator()
- Returns:
- a list iterator over the elements in this list (in proper sequence)
listIterator
ListIterator<E> listIterator(int index)
next
. An initial call to previous
would return the element with the specified index minus one.- Parameters:
-
index
- index of the first element to be returned from the list iterator (by a call tonext
) - Returns:
- a list iterator over the elements in this list (in proper sequence), starting at the specified position in the list
- Throws:
-
IndexOutOfBoundsException
- if the index is out of range (index < 0 || index > size()
)
subList
List<E> subList(int fromIndex, int toIndex)
fromIndex
, inclusive, and toIndex
, exclusive. (If fromIndex
and toIndex
are equal, the returned list is empty.) The returned list is backed by this list, so non-structural changes in the returned list are reflected in this list, and vice-versa. The returned list supports all of the optional list operations supported by this list.This method eliminates the need for explicit range operations (of the sort that commonly exist for arrays). Any operation that expects a list can be used as a range operation by passing a subList view instead of a whole list. For example, the following idiom removes a range of elements from a list:
list.subList(from, to).clear();
Similar idioms may be constructed for indexOf
and lastIndexOf
, and all of the algorithms in the Collections
class can be applied to a subList.The semantics of the list returned by this method become undefined if the backing list (i.e., this list) is structurally modified in any way other than via the returned list. (Structural modifications are those that change the size of this list, or otherwise perturb it in such a fashion that iterations in progress may yield incorrect results.)
- Parameters:
-
fromIndex
- low endpoint (inclusive) of the subList -
toIndex
- high endpoint (exclusive) of the subList - Returns:
- a view of the specified range within this list
- Throws:
-
IndexOutOfBoundsException
- for an illegal endpoint index value (fromIndex < 0 || toIndex > size || fromIndex > toIndex
)
spliterator
default Spliterator<E> spliterator()
Spliterator
over the elements in this list. The Spliterator
reports Spliterator.SIZED
and Spliterator.ORDERED
. Implementations should document the reporting of additional characteristic values.
- Specified by:
-
spliterator
in interfaceCollection<E>
- Specified by:
-
spliterator
in interfaceIterable<E>
- Implementation Requirements:
- The default implementation creates a late-binding spliterator as follows:
- If the list is an instance of
RandomAccess
then the default implementation creates a spliterator that traverses elements by invoking the methodget(int)
. If such invocation results or would result in anIndexOutOfBoundsException
then the spliterator will fail-fast and throw aConcurrentModificationException
. If the list is also an instance ofAbstractList
then the spliterator will use the list'smodCount
field to provide additional fail-fast behavior. - Otherwise, the default implementation creates a spliterator from the list's
Iterator
. The spliterator inherits the fail-fast of the list's iterator.
- If the list is an instance of
- Implementation Note:
- The created
Spliterator
additionally reportsSpliterator.SUBSIZED
. - Returns:
- a
Spliterator
over the elements in this list - Since:
- 1.8
of
static <E> List<E> of()
- Type Parameters:
-
E
- theList
's element type - Returns:
- an empty
List
- Since:
- 9
of
static <E> List<E> of(E e1)
- Type Parameters:
-
E
- theList
's element type - Parameters:
-
e1
- the single element - Returns:
- a
List
containing the specified element - Throws:
-
NullPointerException
- if the element isnull
- Since:
- 9
of
static <E> List<E> of(E e1, E e2)
- Type Parameters:
-
E
- theList
's element type - Parameters:
-
e1
- the first element -
e2
- the second element - Returns:
- a
List
containing the specified elements - Throws:
-
NullPointerException
- if an element isnull
- Since:
- 9
of
static <E> List<E> of(E e1, E e2, E e3)
- Type Parameters:
-
E
- theList
's element type - Parameters:
-
e1
- the first element -
e2
- the second element -
e3
- the third element - Returns:
- a
List
containing the specified elements - Throws:
-
NullPointerException
- if an element isnull
- Since:
- 9
of
static <E> List<E> of(E e1, E e2, E e3, E e4)
- Type Parameters:
-
E
- theList
's element type - Parameters:
-
e1
- the first element -
e2
- the second element -
e3
- the third element -
e4
- the fourth element - Returns:
- a
List
containing the specified elements - Throws:
-
NullPointerException
- if an element isnull
- Since:
- 9
of
static <E> List<E> of(E e1, E e2, E e3, E e4, E e5)
- Type Parameters:
-
E
- theList
's element type - Parameters:
-
e1
- the first element -
e2
- the second element -
e3
- the third element -
e4
- the fourth element -
e5
- the fifth element - Returns:
- a
List
containing the specified elements - Throws:
-
NullPointerException
- if an element isnull
- Since:
- 9
of
static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6)
- Type Parameters:
-
E
- theList
's element type - Parameters:
-
e1
- the first element -
e2
- the second element -
e3
- the third element -
e4
- the fourth element -
e5
- the fifth element -
e6
- the sixth element - Returns:
- a
List
containing the specified elements - Throws:
-
NullPointerException
- if an element isnull
- Since:
- 9
of
static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E e7)
- Type Parameters:
-
E
- theList
's element type - Parameters:
-
e1
- the first element -
e2
- the second element -
e3
- the third element -
e4
- the fourth element -
e5
- the fifth element -
e6
- the sixth element -
e7
- the seventh element - Returns:
- a
List
containing the specified elements - Throws:
-
NullPointerException
- if an element isnull
- Since:
- 9
of
static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8)
- Type Parameters:
-
E
- theList
's element type - Parameters:
-
e1
- the first element -
e2
- the second element -
e3
- the third element -
e4
- the fourth element -
e5
- the fifth element -
e6
- the sixth element -
e7
- the seventh element -
e8
- the eighth element - Returns:
- a
List
containing the specified elements - Throws:
-
NullPointerException
- if an element isnull
- Since:
- 9
of
static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8, E e9)
- Type Parameters:
-
E
- theList
's element type - Parameters:
-
e1
- the first element -
e2
- the second element -
e3
- the third element -
e4
- the fourth element -
e5
- the fifth element -
e6
- the sixth element -
e7
- the seventh element -
e8
- the eighth element -
e9
- the ninth element - Returns:
- a
List
containing the specified elements - Throws:
-
NullPointerException
- if an element isnull
- Since:
- 9
of
static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8, E e9, E e10)
- Type Parameters:
-
E
- theList
's element type - Parameters:
-
e1
- the first element -
e2
- the second element -
e3
- the third element -
e4
- the fourth element -
e5
- the fifth element -
e6
- the sixth element -
e7
- the seventh element -
e8
- the eighth element -
e9
- the ninth element -
e10
- the tenth element - Returns:
- a
List
containing the specified elements - Throws:
-
NullPointerException
- if an element isnull
- Since:
- 9
of
@SafeVarargs static <E> List<E> of(E... elements)
- API Note:
- This method also accepts a single array as an argument. The element type of the resulting list will be the component type of the array, and the size of the list will be equal to the length of the array. To create a list with a single element that is an array, do the following:
This will cause theString[] array = ... ; List<String[]> list = List.<String[]>of(array);
List.of(E)
method to be invoked instead. - Type Parameters:
-
E
- theList
's element type - Parameters:
-
elements
- the elements to be contained in the list - Returns:
- a
List
containing the specified elements - Throws:
-
NullPointerException
- if an element isnull
or if the array isnull
- Since:
- 9
copyOf
static <E> List<E> copyOf(Collection<? extends E> coll)
- Implementation Note:
- If the given Collection is an unmodifiable List, calling copyOf will generally not create a copy.
- Type Parameters:
-
E
- theList
's element type - Parameters:
-
coll
- aCollection
from which elements are drawn, must be non-null - Returns:
- a
List
containing the elements of the givenCollection
- Throws:
-
NullPointerException
- if coll is null, or if it contains any nulls - Since:
- 10
© 1993, 2021, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.
https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/List.html