java.util
Interface List<E>

All Superinterfaces:
Collection sample code for java.util.Collection definition code for java.util.Collection <E>, Iterable sample code for java.lang.Iterable definition code for java.lang.Iterable <E>
All Known Implementing Classes:
AbstractList sample code for java.util.AbstractList definition code for java.util.AbstractList , AbstractSequentialList sample code for java.util.AbstractSequentialList definition code for java.util.AbstractSequentialList , ArrayList sample code for java.util.ArrayList definition code for java.util.ArrayList , AttributeList sample code for javax.management.AttributeList definition code for javax.management.AttributeList , CopyOnWriteArrayList sample code for java.util.concurrent.CopyOnWriteArrayList definition code for java.util.concurrent.CopyOnWriteArrayList , LinkedList sample code for java.util.LinkedList definition code for java.util.LinkedList , RoleList sample code for javax.management.relation.RoleList definition code for javax.management.relation.RoleList , RoleUnresolvedList sample code for javax.management.relation.RoleUnresolvedList definition code for javax.management.relation.RoleUnresolvedList , Stack sample code for java.util.Stack definition code for java.util.Stack , Vector sample code for java.util.Vector definition code for java.util.Vector

public interface List<E>
extends Collection sample code for java.util.Collection definition code for java.util.Collection <E>

An ordered collection (also known as a sequence). The user of this interface has precise control over where in the list each element is inserted. The user can access elements by their integer index (position in the list), and search for elements in the list.

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 a 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.

This interface is a member of the Java Collections Framework.

Since:
1.2
See Also:
Collection sample code for java.util.Collection definition code for java.util.Collection , Set sample code for java.util.Set definition code for java.util.Set , ArrayList sample code for java.util.ArrayList definition code for java.util.ArrayList , LinkedList sample code for java.util.LinkedList definition code for java.util.LinkedList , Vector sample code for java.util.Vector definition code for java.util.Vector , Arrays.asList(Object[]) sample code for java.util.Arrays.asList(T...) definition code for java.util.Arrays.asList(T...) , Collections.nCopies(int, Object) sample code for java.util.Collections.nCopies(int, T) definition code for java.util.Collections.nCopies(int, T) , Collections.EMPTY_LIST sample code for java.util.Collections.EMPTY_LIST definition code for java.util.Collections.EMPTY_LIST , AbstractList sample code for java.util.AbstractList definition code for java.util.AbstractList , AbstractSequentialList sample code for java.util.AbstractSequentialList definition code for java.util.AbstractSequentialList

Method Summary
 boolean add sample code for java.util.List.add(E) definition code for java.util.List.add(E) (E o)
          Appends the specified element to the end of this list (optional operation).
 void add sample code for java.util.List.add(int, E) definition code for java.util.List.add(int, E) (int index, E element)
          Inserts the specified element at the specified position in this list (optional operation).
 boolean addAll sample code for java.util.List.addAll(java.util.Collection) definition code for java.util.List.addAll(java.util.Collection) (Collection sample code for java.util.Collection definition code for java.util.Collection <? extends E> c)
          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).
 boolean addAll sample code for java.util.List.addAll(int, java.util.Collection) definition code for java.util.List.addAll(int, java.util.Collection) (int index, Collection sample code for java.util.Collection definition code for java.util.Collection <? extends E> c)
          Inserts all of the elements in the specified collection into this list at the specified position (optional operation).
 void clear sample code for java.util.List.clear() definition code for java.util.List.clear() ()
          Removes all of the elements from this list (optional operation).
 boolean contains sample code for java.util.List.contains(java.lang.Object) definition code for java.util.List.contains(java.lang.Object) (Object sample code for java.lang.Object definition code for java.lang.Object  o)
          Returns true if this list contains the specified element.
 boolean containsAll sample code for java.util.List.containsAll(java.util.Collection) definition code for java.util.List.containsAll(java.util.Collection) (Collection sample code for java.util.Collection definition code for java.util.Collection <?> c)
          Returns true if this list contains all of the elements of the specified collection.
 boolean equals sample code for java.util.List.equals(java.lang.Object) definition code for java.util.List.equals(java.lang.Object) (Object sample code for java.lang.Object definition code for java.lang.Object  o)
          Compares the specified object with this list for equality.
 E get sample code for java.util.List.get(int) definition code for java.util.List.get(int) (int index)
          Returns the element at the specified position in this list.
 int hashCode sample code for java.util.List.hashCode() definition code for java.util.List.hashCode() ()
          Returns the hash code value for this list.
 int indexOf sample code for java.util.List.indexOf(java.lang.Object) definition code for java.util.List.indexOf(java.lang.Object) (Object sample code for java.lang.Object definition code for java.lang.Object  o)
          Returns the index in this list of the first occurrence of the specified element, or -1 if this list does not contain this element.
 boolean isEmpty sample code for java.util.List.isEmpty() definition code for java.util.List.isEmpty() ()
          Returns true if this list contains no elements.
 Iterator sample code for java.util.Iterator definition code for java.util.Iterator <E> iterator sample code for java.util.List.iterator() definition code for java.util.List.iterator() ()
          Returns an iterator over the elements in this list in proper sequence.
 int lastIndexOf sample code for java.util.List.lastIndexOf(java.lang.Object) definition code for java.util.List.lastIndexOf(java.lang.Object) (Object sample code for java.lang.Object definition code for java.lang.Object  o)
          Returns the index in this list of the last occurrence of the specified element, or -1 if this list does not contain this element.
 ListIterator sample code for java.util.ListIterator definition code for java.util.ListIterator <E> listIterator sample code for java.util.List.listIterator() definition code for java.util.List.listIterator() ()
          Returns a list iterator of the elements in this list (in proper sequence).
 ListIterator sample code for java.util.ListIterator definition code for java.util.ListIterator <E> listIterator sample code for java.util.List.listIterator(int) definition code for java.util.List.listIterator(int) (int index)
          Returns a list iterator of the elements in this list (in proper sequence), starting at the specified position in this list.
 E remove sample code for java.util.List.remove(int) definition code for java.util.List.remove(int) (int index)
          Removes the element at the specified position in this list (optional operation).
 boolean remove sample code for java.util.List.remove(java.lang.Object) definition code for java.util.List.remove(java.lang.Object) (Object sample code for java.lang.Object definition code for java.lang.Object  o)
          Removes the first occurrence in this list of the specified element (optional operation).
 boolean removeAll sample code for java.util.List.removeAll(java.util.Collection) definition code for java.util.List.removeAll(java.util.Collection) (Collection sample code for java.util.Collection definition code for java.util.Collection <?> c)
          Removes from this list all the elements that are contained in the specified collection (optional operation).
 boolean retainAll sample code for java.util.List.retainAll(java.util.Collection) definition code for java.util.List.retainAll(java.util.Collection) (Collection sample code for java.util.Collection definition code for java.util.Collection <?> c)
          Retains only the elements in this list that are contained in the specified collection (optional operation).
 E set sample code for java.util.List.set(int, E) definition code for java.util.List.set(int, E) (int index, E element)
          Replaces the element at the specified position in this list with the specified element (optional operation).
 int size sample code for java.util.List.size() definition code for java.util.List.size() ()
          Returns the number of elements in this list.
 List sample code for java.util.List definition code for java.util.List <E> subList sample code for java.util.List.subList(int, int) definition code for java.util.List.subList(int, int) (int fromIndex, int toIndex)
          Returns a view of the portion of this list between the specified fromIndex, inclusive, and toIndex, exclusive.
 Object sample code for java.lang.Object definition code for java.lang.Object [] toArray sample code for java.util.List.toArray() definition code for java.util.List.toArray() ()
          Returns an array containing all of the elements in this list in proper sequence.
<T> T[]
toArray sample code for java.util.List.toArray(T[]) definition code for java.util.List.toArray(T[]) (T[] a)
          Returns an array containing all of the elements in this list in proper sequence; the runtime type of the returned array is that of the specified array.
 

Method Detail

size sample code for java.util.List.size() definition code for java.util.List.size()

int size()
Returns the number of elements in this list. If this list contains more than Integer.MAX_VALUE elements, returns Integer.MAX_VALUE.

Specified by:
size sample code for java.util.Collection.size() definition code for java.util.Collection.size() in interface Collection sample code for java.util.Collection definition code for java.util.Collection <E>
Returns:
the number of elements in this list.

isEmpty sample code for java.util.List.isEmpty() definition code for java.util.List.isEmpty()

boolean isEmpty()
Returns true if this list contains no elements.

Specified by:
isEmpty sample code for java.util.Collection.isEmpty() definition code for java.util.Collection.isEmpty() in interface Collection sample code for java.util.Collection definition code for java.util.Collection <E>
Returns:
true if this list contains no elements.

contains sample code for java.util.List.contains(java.lang.Object) definition code for java.util.List.contains(java.lang.Object)

boolean contains(Object sample code for java.lang.Object definition code for java.lang.Object  o)
Returns 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 (o==null ? e==null : o.equals(e)).

Specified by:
contains sample code for java.util.Collection.contains(java.lang.Object) definition code for java.util.Collection.contains(java.lang.Object) in interface Collection sample code for java.util.Collection definition code for java.util.Collection <E>
Parameters:
o - element whose presence in this list is to be tested.
Returns:
true if this list contains the specified element.
Throws:
ClassCastException sample code for java.lang.ClassCastException definition code for java.lang.ClassCastException - if the type of the specified element is incompatible with this list (optional).
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if the specified element is null and this list does not support null elements (optional).

iterator sample code for java.util.List.iterator() definition code for java.util.List.iterator()

Iterator sample code for java.util.Iterator definition code for java.util.Iterator <E> iterator()
Returns an iterator over the elements in this list in proper sequence.

Specified by:
iterator sample code for java.util.Collection.iterator() definition code for java.util.Collection.iterator() in interface Collection sample code for java.util.Collection definition code for java.util.Collection <E>
Specified by:
iterator sample code for java.lang.Iterable.iterator() definition code for java.lang.Iterable.iterator() in interface Iterable sample code for java.lang.Iterable definition code for java.lang.Iterable <E>
Returns:
an iterator over the elements in this list in proper sequence.

toArray sample code for java.util.List.toArray() definition code for java.util.List.toArray()

Object sample code for java.lang.Object definition code for java.lang.Object [] toArray()
Returns an array containing all of the elements in this list in proper sequence. Obeys the general contract of the Collection.toArray method.

Specified by:
toArray sample code for java.util.Collection.toArray() definition code for java.util.Collection.toArray() in interface Collection sample code for java.util.Collection definition code for java.util.Collection <E>
Returns:
an array containing all of the elements in this list in proper sequence.
See Also:
Arrays.asList(Object[]) sample code for java.util.Arrays.asList(T...) definition code for java.util.Arrays.asList(T...)

toArray sample code for java.util.List.<T>toArray(T[]) definition code for java.util.List.<T>toArray(T[])

<T> T[] toArray(T[] a)
Returns an array containing all of the elements in this list in proper sequence; the runtime type of the returned array is that of the specified array. Obeys the general contract of the Collection.toArray(Object[]) method.

Specified by:
toArray sample code for java.util.Collection.toArray(T[]) definition code for java.util.Collection.toArray(T[]) in interface Collection sample code for java.util.Collection definition code for java.util.Collection <E>
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 sample code for java.lang.ArrayStoreException definition code for java.lang.ArrayStoreException - if the runtime type of the specified array is not a supertype of the runtime type of every element in this list.
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if the specified array is null.

add sample code for java.util.List.add(E) definition code for java.util.List.add(E)

boolean add(E o)
Appends the specified element to the end of this list (optional operation).

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 sample code for java.util.Collection.add(E) definition code for java.util.Collection.add(E) in interface Collection sample code for java.util.Collection definition code for java.util.Collection <E>
Parameters:
o - element to be appended to this list.
Returns:
true (as per the general contract of the Collection.add method).
Throws:
UnsupportedOperationException sample code for java.lang.UnsupportedOperationException definition code for java.lang.UnsupportedOperationException - if the add method is not supported by this list.
ClassCastException sample code for java.lang.ClassCastException definition code for java.lang.ClassCastException - if the class of the specified element prevents it from being added to this list.
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if the specified element is null and this list does not support null elements.
IllegalArgumentException sample code for java.lang.IllegalArgumentException definition code for java.lang.IllegalArgumentException - if some aspect of this element prevents it from being added to this list.

remove sample code for java.util.List.remove(java.lang.Object) definition code for java.util.List.remove(java.lang.Object)

boolean remove(Object sample code for java.lang.Object definition code for java.lang.Object  o)
Removes the first occurrence in this list of the specified element (optional operation). If this list does not contain the element, it is unchanged. More formally, removes the element with the lowest index i such that (o==null ? get(i)==null : o.equals(get(i))) (if such an element exists).

Specified by:
remove sample code for java.util.Collection.remove(java.lang.Object) definition code for java.util.Collection.remove(java.lang.Object) in interface Collection sample code for java.util.Collection definition code for java.util.Collection <E>
Parameters:
o - element to be removed from this list, if present.
Returns:
true if this list contained the specified element.
Throws:
ClassCastException sample code for java.lang.ClassCastException definition code for java.lang.ClassCastException - if the type of the specified element is incompatible with this list (optional).
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if the specified element is null and this list does not support null elements (optional).
UnsupportedOperationException sample code for java.lang.UnsupportedOperationException definition code for java.lang.UnsupportedOperationException - if the remove method is not supported by this list.

containsAll sample code for java.util.List.containsAll(java.util.Collection<?>) definition code for java.util.List.containsAll(java.util.Collection<?>)

boolean containsAll(Collection sample code for java.util.Collection definition code for java.util.Collection <?> c)
Returns true if this list contains all of the elements of the specified collection.

Specified by:
containsAll sample code for java.util.Collection.containsAll(java.util.Collection) definition code for java.util.Collection.containsAll(java.util.Collection) in interface Collection sample code for java.util.Collection definition code for java.util.Collection <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 sample code for java.lang.ClassCastException definition code for java.lang.ClassCastException - if the types of one or more elements in the specified collection are incompatible with this list (optional).
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if the specified collection contains one or more null elements and this list does not support null elements (optional).
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if the specified collection is null.
See Also:
contains(Object) sample code for java.util.List.contains(java.lang.Object) definition code for java.util.List.contains(java.lang.Object)

addAll sample code for java.util.List.addAll(java.util.Collection<? extends E>) definition code for java.util.List.addAll(java.util.Collection<? extends E>)

boolean addAll(Collection sample code for java.util.Collection definition code for java.util.Collection <? extends E> c)
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). The behavior of this operation is unspecified if the specified collection is modified while the operation is in progress. (Note that this will occur if the specified collection is this list, and it's nonempty.)

Specified by:
addAll sample code for java.util.Collection.addAll(java.util.Collection) definition code for java.util.Collection.addAll(java.util.Collection) in interface Collection sample code for java.util.Collection definition code for java.util.Collection <E>
Parameters:
c - collection whose elements are to be added to this list.
Returns:
true if this list changed as a result of the call.
Throws:
UnsupportedOperationException sample code for java.lang.UnsupportedOperationException definition code for java.lang.UnsupportedOperationException - if the addAll method is not supported by this list.
ClassCastException sample code for java.lang.ClassCastException definition code for java.lang.ClassCastException - if the class of an element in the specified collection prevents it from being added to this list.
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if the specified collection contains one or more null elements and this list does not support null elements, or if the specified collection is null.
IllegalArgumentException sample code for java.lang.IllegalArgumentException definition code for java.lang.IllegalArgumentException - if some aspect of an element in the specified collection prevents it from being added to this list.
See Also:
add(Object) sample code for java.util.List.add(E) definition code for java.util.List.add(E)

addAll sample code for java.util.List.addAll(int, java.util.Collection<? extends E>) definition code for java.util.List.addAll(int, java.util.Collection<? extends E>)

boolean addAll(int index,
               Collection sample code for java.util.Collection definition code for java.util.Collection <? extends E> c)
Inserts all of the elements in the specified collection into this list at the specified position (optional operation). Shifts the element currently at that position (if any) and any subsequent elements to the right (increases their indices). The new elements will appear in this list in the order that they are returned by the specified collection's iterator. The behavior of this operation is unspecified if the specified collection is modified while the operation is in progress. (Note that this will occur if the specified collection is this list, and it's nonempty.)

Parameters:
index - index at which to insert first element from the specified collection.
c - elements to be inserted into this list.
Returns:
true if this list changed as a result of the call.
Throws:
UnsupportedOperationException sample code for java.lang.UnsupportedOperationException definition code for java.lang.UnsupportedOperationException - if the addAll method is not supported by this list.
ClassCastException sample code for java.lang.ClassCastException definition code for java.lang.ClassCastException - if the class of one of elements of the specified collection prevents it from being added to this list.
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if the specified collection contains one or more null elements and this list does not support null elements, or if the specified collection is null.
IllegalArgumentException sample code for java.lang.IllegalArgumentException definition code for java.lang.IllegalArgumentException - if some aspect of one of elements of the specified collection prevents it from being added to this list.
IndexOutOfBoundsException sample code for java.lang.IndexOutOfBoundsException definition code for java.lang.IndexOutOfBoundsException - if the index is out of range (index < 0 || index > size()).

removeAll sample code for java.util.List.removeAll(java.util.Collection<?>) definition code for java.util.List.removeAll(java.util.Collection<?>)

boolean removeAll(Collection sample code for java.util.Collection definition code for java.util.Collection <?> c)
Removes from this list all the elements that are contained in the specified collection (optional operation).

Specified by:
removeAll sample code for java.util.Collection.removeAll(java.util.Collection) definition code for java.util.Collection.removeAll(java.util.Collection) in interface Collection sample code for java.util.Collection definition code for java.util.Collection <E>
Parameters:
c - collection that defines which elements will be removed from this list.
Returns:
true if this list changed as a result of the call.
Throws:
UnsupportedOperationException sample code for java.lang.UnsupportedOperationException definition code for java.lang.UnsupportedOperationException - if the removeAll method is not supported by this list.
ClassCastException sample code for java.lang.ClassCastException definition code for java.lang.ClassCastException - if the types of one or more elements in this list are incompatible with the specified collection (optional).
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if this list contains one or more null elements and the specified collection does not support null elements (optional).
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if the specified collection is null.
See Also:
remove(Object) sample code for java.util.List.remove(java.lang.Object) definition code for java.util.List.remove(java.lang.Object) , contains(Object) sample code for java.util.List.contains(java.lang.Object) definition code for java.util.List.contains(java.lang.Object)

retainAll sample code for java.util.List.retainAll(java.util.Collection<?>) definition code for java.util.List.retainAll(java.util.Collection<?>)

boolean retainAll(Collection sample code for java.util.Collection definition code for java.util.Collection <?> c)
Retains only the elements in this list that are contained in the specified collection (optional operation). In other words, removes from this list all the elements that are not contained in the specified collection.

Specified by:
retainAll sample code for java.util.Collection.retainAll(java.util.Collection) definition code for java.util.Collection.retainAll(java.util.Collection) in interface Collection sample code for java.util.Collection definition code for java.util.Collection <E>
Parameters:
c - collection that defines which elements this set will retain.
Returns:
true if this list changed as a result of the call.
Throws:
UnsupportedOperationException sample code for java.lang.UnsupportedOperationException definition code for java.lang.UnsupportedOperationException - if the retainAll method is not supported by this list.
ClassCastException sample code for java.lang.ClassCastException definition code for java.lang.ClassCastException - if the types of one or more elements in this list are incompatible with the specified collection (optional).
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if this list contains one or more null elements and the specified collection does not support null elements (optional).
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if the specified collection is null.
See Also:
remove(Object) sample code for java.util.List.remove(java.lang.Object) definition code for java.util.List.remove(java.lang.Object) , contains(Object) sample code for java.util.List.contains(java.lang.Object) definition code for java.util.List.contains(java.lang.Object)

clear sample code for java.util.List.clear() definition code for java.util.List.clear()

void clear()
Removes all of the elements from this list (optional operation). This list will be empty after this call returns (unless it throws an exception).

Specified by:
clear sample code for java.util.Collection.clear() definition code for java.util.Collection.clear() in interface Collection sample code for java.util.Collection definition code for java.util.Collection <E>
Throws:
UnsupportedOperationException sample code for java.lang.UnsupportedOperationException definition code for java.lang.UnsupportedOperationException - if the clear method is not supported by this list.

equals sample code for java.util.List.equals(java.lang.Object) definition code for java.util.List.equals(java.lang.Object)

boolean equals(Object sample code for java.lang.Object definition code for java.lang.Object  o)
Compares the specified object with this list for equality. Returns 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 (e1==null ? e2==null : e1.equals(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 sample code for java.util.Collection.equals(java.lang.Object) definition code for java.util.Collection.equals(java.lang.Object) in interface Collection sample code for java.util.Collection definition code for java.util.Collection <E>
Overrides:
equals sample code for java.lang.Object.equals(java.lang.Object) definition code for java.lang.Object.equals(java.lang.Object) in class Object sample code for java.lang.Object definition code for java.lang.Object
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:
Object.hashCode() sample code for java.lang.Object.hashCode() definition code for java.lang.Object.hashCode() , Hashtable sample code for java.util.Hashtable definition code for java.util.Hashtable

hashCode sample code for java.util.List.hashCode() definition code for java.util.List.hashCode()

int hashCode()
Returns the hash code value for this list. The hash code of a list is defined to be the result of the following calculation:
  hashCode = 1;
  Iterator i = list.iterator();
  while (i.hasNext()) {
      Object obj = i.next();
      hashCode = 31*hashCode + (obj==null ? 0 : obj.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 sample code for java.util.Collection.hashCode() definition code for java.util.Collection.hashCode() in interface Collection sample code for java.util.Collection definition code for java.util.Collection <E>
Overrides:
hashCode sample code for java.lang.Object.hashCode() definition code for java.lang.Object.hashCode() in class Object sample code for java.lang.Object definition code for java.lang.Object
Returns:
the hash code value for this list.
See Also:
Object.hashCode() sample code for java.lang.Object.hashCode() definition code for java.lang.Object.hashCode() , Object.equals(Object) sample code for java.lang.Object.equals(java.lang.Object) definition code for java.lang.Object.equals(java.lang.Object) , equals(Object) sample code for java.util.List.equals(java.lang.Object) definition code for java.util.List.equals(java.lang.Object)

get sample code for java.util.List.get(int) definition code for java.util.List.get(int)

E get(int index)
Returns the element at the specified position in this list.

Parameters:
index - index of element to return.
Returns:
the element at the specified position in this list.
Throws:
IndexOutOfBoundsException sample code for java.lang.IndexOutOfBoundsException definition code for java.lang.IndexOutOfBoundsException - if the index is out of range (index < 0 || index >= size()).

set sample code for java.util.List.set(int, E) definition code for java.util.List.set(int, E)

E set(int index,
      E element)
Replaces the element at the specified position in this list with the specified element (optional operation).

Parameters:
index - index of element to replace.
element - element to be stored at the specified position.
Returns:
the element previously at the specified position.
Throws:
UnsupportedOperationException sample code for java.lang.UnsupportedOperationException definition code for java.lang.UnsupportedOperationException - if the set method is not supported by this list.
ClassCastException sample code for java.lang.ClassCastException definition code for java.lang.ClassCastException - if the class of the specified element prevents it from being added to this list.
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if the specified element is null and this list does not support null elements.
IllegalArgumentException sample code for java.lang.IllegalArgumentException definition code for java.lang.IllegalArgumentException - if some aspect of the specified element prevents it from being added to this list.
IndexOutOfBoundsException sample code for java.lang.IndexOutOfBoundsException definition code for java.lang.IndexOutOfBoundsException - if the index is out of range (index < 0 || index >= size()).

add sample code for java.util.List.add(int, E) definition code for java.util.List.add(int, E)

void add(int index,
         E element)
Inserts the specified element at the specified position in this list (optional operation). Shifts the element currently at that position (if any) and any subsequent elements to the right (adds one to their indices).

Parameters:
index - index at which the specified element is to be inserted.
element - element to be inserted.
Throws:
UnsupportedOperationException sample code for java.lang.UnsupportedOperationException definition code for java.lang.UnsupportedOperationException - if the add method is not supported by this list.
ClassCastException sample code for java.lang.ClassCastException definition code for java.lang.ClassCastException - if the class of the specified element prevents it from being added to this list.
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if the specified element is null and this list does not support null elements.
IllegalArgumentException sample code for java.lang.IllegalArgumentException definition code for java.lang.IllegalArgumentException - if some aspect of the specified element prevents it from being added to this list.
IndexOutOfBoundsException sample code for java.lang.IndexOutOfBoundsException definition code for java.lang.IndexOutOfBoundsException - if the index is out of range (index < 0 || index > size()).

remove sample code for java.util.List.remove(int) definition code for java.util.List.remove(int)

E remove(int index)
Removes the element at the specified position in this list (optional operation). Shifts any subsequent elements to the left (subtracts one from their indices). Returns the element that was removed from the list.

Parameters:
index - the index of the element to removed.
Returns:
the element previously at the specified position.
Throws:
UnsupportedOperationException sample code for java.lang.UnsupportedOperationException definition code for java.lang.UnsupportedOperationException - if the remove method is not supported by this list.
IndexOutOfBoundsException sample code for java.lang.IndexOutOfBoundsException definition code for java.lang.IndexOutOfBoundsException - if the index is out of range (index < 0 || index >= size()).

indexOf sample code for java.util.List.indexOf(java.lang.Object) definition code for java.util.List.indexOf(java.lang.Object)

int indexOf(Object sample code for java.lang.Object definition code for java.lang.Object  o)
Returns the index in this list of the first occurrence of the specified element, or -1 if this list does not contain this element. More formally, returns the lowest index i such that (o==null ? get(i)==null : o.equals(get(i))), or -1 if there is no such index.

Parameters:
o - element to search for.
Returns:
the index in this list of the first occurrence of the specified element, or -1 if this list does not contain this element.
Throws:
ClassCastException sample code for java.lang.ClassCastException definition code for java.lang.ClassCastException - if the type of the specified element is incompatible with this list (optional).
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if the specified element is null and this list does not support null elements (optional).

lastIndexOf sample code for java.util.List.lastIndexOf(java.lang.Object) definition code for java.util.List.lastIndexOf(java.lang.Object)

int lastIndexOf(Object sample code for java.lang.Object definition code for java.lang.Object  o)
Returns the index in this list of the last occurrence of the specified element, or -1 if this list does not contain this element. More formally, returns the highest index i such that (o==null ? get(i)==null : o.equals(get(i))), or -1 if there is no such index.

Parameters:
o - element to search for.
Returns:
the index in this list of the last occurrence of the specified element, or -1 if this list does not contain this element.
Throws:
ClassCastException sample code for java.lang.ClassCastException definition code for java.lang.ClassCastException - if the type of the specified element is incompatible with this list (optional).
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if the specified element is null and this list does not support null elements (optional).

listIterator sample code for java.util.List.listIterator() definition code for java.util.List.listIterator()

ListIterator sample code for java.util.ListIterator definition code for java.util.ListIterator <E> listIterator()
Returns a list iterator of the elements in this list (in proper sequence).

Returns:
a list iterator of the elements in this list (in proper sequence).

listIterator sample code for java.util.List.listIterator(int) definition code for java.util.List.listIterator(int)

ListIterator sample code for java.util.ListIterator definition code for java.util.ListIterator <E> listIterator(int index)
Returns a list iterator of the elements in this list (in proper sequence), starting at the specified position in this list. The specified index indicates the first element that would be returned by an initial call to the next method. An initial call to the previous method would return the element with the specified index minus one.

Parameters:
index - index of first element to be returned from the list iterator (by a call to the next method).
Returns:
a list iterator of the elements in this list (in proper sequence), starting at the specified position in this list.
Throws:
IndexOutOfBoundsException sample code for java.lang.IndexOutOfBoundsException definition code for java.lang.IndexOutOfBoundsException - if the index is out of range (index < 0 || index > size()).

subList sample code for java.util.List.subList(int, int) definition code for java.util.List.subList(int, int)

List sample code for java.util.List definition code for java.util.List <E> subList(int fromIndex,
                int toIndex)
Returns a view of the portion of this list between the specified 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 sample code for java.lang.IndexOutOfBoundsException definition code for java.lang.IndexOutOfBoundsException - for an illegal endpoint index value (fromIndex < 0 || toIndex > size || fromIndex > toIndex).