java.util
Class Vector<E>

java.lang.Object
  java.util.AbstractCollection<E>
      java.util.AbstractList<E>
          java.util.Vector<E>

All Implemented Interfaces:

Serializable, Cloneable, Iterable<E>, Collection<E>, List<E>, RandomAccess

Direct Known Subclasses:

Stack

public class Vector<E>
extends AbstractList<E>
implements List<E>, RandomAccess, Cloneable, Serializable

The Vector class implements a growable array of objects. Like an array, it contains components that can be accessed using an integer index. However, the size of a Vector can grow or shrink as needed to accommodate adding and removing items after the Vector has been created.

Each vector tries to optimize storage management by maintaining a capacity and a capacityIncrement. The capacity is always at least as large as the vector size; it is usually larger because as components are added to the vector, the vector's storage increases in chunks the size of capacityIncrement. An application can increase the capacity of a vector before inserting a large number of components; this reduces the amount of incremental reallocation.

The Iterators returned by Vector's iterator and listIterator methods are fail-fast: if the Vector is structurally modified at any time after the Iterator is created, in any way except through the Iterator's own remove or add methods, the Iterator will throw a ConcurrentModificationException. Thus, in the face of concurrent modification, the Iterator fails quickly and cleanly, rather than risking arbitrary, non-deterministic behavior at an undetermined time in the future. The Enumerations returned by Vector's elements method are not fail-fast.

Note that the fail-fast behavior of an iterator cannot be guaranteed as it is, generally speaking, impossible to make any hard guarantees in the presence of unsynchronized concurrent modification. Fail-fast iterators throw ConcurrentModificationException on a best-effort basis. Therefore, it would be wrong to write a program that depended on this exception for its correctness: the fail-fast behavior of iterators should be used only to detect bugs.

As of the Java 2 platform v1.2, this class was retrofitted to implement the List interface, making it a member of the Java Collections Framework. Unlike the new collection implementations, Vector is synchronized.

Since:

JDK1.0

See Also:

Collection, List, ArrayList, LinkedList, Serialized Form

Field Summary

protected int	capacityIncrement The amount by which the capacity of the vector is automatically incremented when its size becomes greater than its capacity.
protected int	elementCount The number of valid components in this Vector object.
protected Object[]	elementData The array buffer into which the components of the vector are stored.

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

Vector()
Constructs an empty vector so that its internal data array has size 10 and its standard capacity increment is zero.

Vector(Collection<? extends E> c)
Constructs a vector containing the elements of the specified collection, in the order they are returned by the collection's iterator.

Vector(int initialCapacity)
Constructs an empty vector with the specified initial capacity and with its capacity increment equal to zero.

Vector(int initialCapacity, int capacityIncrement)
Constructs an empty vector with the specified initial capacity and capacity increment.

Method Summary

boolean	add(E e) Appends the specified element to the end of this Vector.
void	add(int index, E element) Inserts the specified element at the specified position in this Vector.
boolean	addAll(Collection<? extends E> c) Appends all of the elements in the specified Collection to the end of this Vector, in the order that they are returned by the specified Collection's Iterator.
boolean	addAll(int index, Collection<? extends E> c) Inserts all of the elements in the specified Collection into this Vector at the specified position.
void	addElement(E obj) Adds the specified component to the end of this vector, increasing its size by one.
int	capacity() Returns the current capacity of this vector.
void	clear() Removes all of the elements from this Vector.
Object	clone() Returns a clone of this vector.
boolean	contains(Object o) Returns true if this vector contains the specified element.
boolean	containsAll(Collection<?> c) Returns true if this Vector contains all of the elements in the specified Collection.
void	copyInto(Object[] anArray) Copies the components of this vector into the specified array.
E	elementAt(int index) Returns the component at the specified index.
Enumeration<E>	elements() Returns an enumeration of the components of this vector.
void	ensureCapacity(int minCapacity) Increases the capacity of this vector, if necessary, to ensure that it can hold at least the number of components specified by the minimum capacity argument.
boolean	equals(Object o) Compares the specified Object with this Vector for equality.
E	firstElement() Returns the first component (the item at index 0) of this vector.
E	get(int index) Returns the element at the specified position in this Vector.
int	hashCode() Returns the hash code value for this Vector.
int	indexOf(Object o) Returns the index of the first occurrence of the specified element in this vector, or -1 if this vector does not contain the element.
int	indexOf(Object o, int index) Returns the index of the first occurrence of the specified element in this vector, searching forwards from index, or returns -1 if the element is not found.
void	insertElementAt(E obj, int index) Inserts the specified object as a component in this vector at the specified index.
boolean	isEmpty() Tests if this vector has no components.
E	lastElement() Returns the last component of the vector.
int	lastIndexOf(Object o) Returns the index of the last occurrence of the specified element in this vector, or -1 if this vector does not contain the element.
int	lastIndexOf(Object o, int index) Returns the index of the last occurrence of the specified element in this vector, searching backwards from index, or returns -1 if the element is not found.
E	remove(int index) Removes the element at the specified position in this Vector.
boolean	remove(Object o) Removes the first occurrence of the specified element in this Vector If the Vector does not contain the element, it is unchanged.
boolean	removeAll(Collection<?> c) Removes from this Vector all of its elements that are contained in the specified Collection.
void	removeAllElements() Removes all components from this vector and sets its size to zero.
boolean	removeElement(Object obj) Removes the first (lowest-indexed) occurrence of the argument from this vector.
void	removeElementAt(int index) Deletes the component at the specified index.
protected void	removeRange(int fromIndex, int toIndex) Removes from this List all of the elements whose index is between fromIndex, inclusive and toIndex, exclusive.
boolean	retainAll(Collection<?> c) Retains only the elements in this Vector that are contained in the specified Collection.
E	set(int index, E element) Replaces the element at the specified position in this Vector with the specified element.
void	setElementAt(E obj, int index) Sets the component at the specified index of this vector to be the specified object.
void	setSize(int newSize) Sets the size of this vector.
int	size() Returns the number of components in this vector.
List<E>	subList(int fromIndex, int toIndex) Returns a view of the portion of this List between fromIndex, inclusive, and toIndex, exclusive.
Object[]	toArray() Returns an array containing all of the elements in this Vector in the correct order.
<T> T[]	toArray(T[] a) Returns an array containing all of the elements in this Vector in the correct order; the runtime type of the returned array is that of the specified array.
String	toString() Returns a string representation of this Vector, containing the String representation of each element.
void	trimToSize() Trims the capacity of this vector to be the vector's current size.

Methods inherited from class java.util.AbstractList

iterator, listIterator, listIterator

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.List

iterator, listIterator, listIterator

Field Detail

elementData

protected Object[] elementData

The array buffer into which the components of the vector are stored. The capacity of the vector is the length of this array buffer, and is at least large enough to contain all the vector's elements.

Any array elements following the last element in the Vector are null.

elementCount

protected int elementCount

The number of valid components in this Vector object. Components elementData[0] through elementData[elementCount-1] are the actual items.

capacityIncrement

protected int capacityIncrement

The amount by which the capacity of the vector is automatically incremented when its size becomes greater than its capacity. If the capacity increment is less than or equal to zero, the capacity of the vector is doubled each time it needs to grow.

Constructor Detail

Vector

public Vector(int initialCapacity,
              int capacityIncrement)

Constructs an empty vector with the specified initial capacity and capacity increment.

Parameters:

initialCapacity - the initial capacity of the vector

capacityIncrement - the amount by which the capacity is increased when the vector overflows

Throws:

IllegalArgumentException - if the specified initial capacity is negative

Vector

public Vector(int initialCapacity)

Constructs an empty vector with the specified initial capacity and with its capacity increment equal to zero.

Parameters:

initialCapacity - the initial capacity of the vector

Throws:

IllegalArgumentException - if the specified initial capacity is negative

Vector

public Vector()

Constructs an empty vector so that its internal data array has size 10 and its standard capacity increment is zero.

Vector

public Vector(Collection<? extends E> c)

Constructs a vector containing the elements of the specified collection, in the order they are returned by the collection's iterator.

Parameters:

c - the collection whose elements are to be placed into this vector

Throws:

NullPointerException - if the specified collection is null

Since:

1.2

Method Detail

copyInto

public void copyInto(Object[] anArray)

Copies the components of this vector into the specified array. The item at index k in this vector is copied into component k of anArray.

Parameters:

anArray - the array into which the components get copied

Throws:

NullPointerException - if the given array is null

IndexOutOfBoundsException - if the specified array is not large enough to hold all the components of this vector

ArrayStoreException - if a component of this vector is not of a runtime type that can be stored in the specified array

See Also:

toArray(Object[])

trimToSize

public void trimToSize()

Trims the capacity of this vector to be the vector's current size. If the capacity of this vector is larger than its current size, then the capacity is changed to equal the size by replacing its internal data array, kept in the field elementData, with a smaller one. An application can use this operation to minimize the storage of a vector.

ensureCapacity

public void ensureCapacity(int minCapacity)

Increases the capacity of this vector, if necessary, to ensure that it can hold at least the number of components specified by the minimum capacity argument.

If the current capacity of this vector is less than minCapacity, then its capacity is increased by replacing its internal data array, kept in the field elementData, with a larger one. The size of the new data array will be the old size plus capacityIncrement, unless the value of capacityIncrement is less than or equal to zero, in which case the new capacity will be twice the old capacity; but if this new size is still smaller than minCapacity, then the new capacity will be minCapacity.

Parameters:

minCapacity - the desired minimum capacity

setSize

public void setSize(int newSize)

Sets the size of this vector. If the new size is greater than the current size, new null items are added to the end of the vector. If the new size is less than the current size, all components at index newSize and greater are discarded.

Parameters:

newSize - the new size of this vector

Throws:

ArrayIndexOutOfBoundsException - if the new size is negative

capacity

public int capacity()

Returns the current capacity of this vector.

Returns:

the current capacity (the length of its internal data array, kept in the field elementData of this vector)

size

public int size()

Returns the number of components in this vector.

Specified by:

size in interface Collection<E>

Specified by:

size in interface List<E>

Specified by:

size in class AbstractCollection<E>

Returns:

the number of components in this vector

isEmpty

public boolean isEmpty()

Tests if this vector has no components.

Specified by:

isEmpty in interface Collection<E>

Specified by:

isEmpty in interface List<E>

Overrides:

isEmpty in class AbstractCollection<E>

Returns:

true if and only if this vector has no components, that is, its size is zero; false otherwise.

elements

public Enumeration<E> elements()

Returns an enumeration of the components of this vector. The returned Enumeration object will generate all items in this vector. The first item generated is the item at index 0, then the item at index 1, and so on.

Returns:

an enumeration of the components of this vector

See Also:

Iterator

contains

public boolean contains(Object o)

Returns true if this vector contains the specified element. More formally, returns true if and only if this vector contains at least one element e such that (o==null ? e==null : o.equals(e)).

Specified by:

contains in interface Collection<E>

Specified by:

contains in interface List<E>

Overrides:

contains in class AbstractCollection<E>

Parameters:

o - element whose presence in this vector is to be tested

Returns:

true if this vector contains the specified element

indexOf

public int indexOf(Object o)

Returns the index of the first occurrence of the specified element in this vector, or -1 if this vector does not contain the 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.

Specified by:

indexOf in interface List<E>

Overrides:

indexOf in class AbstractList<E>

Parameters:

o - element to search for

Returns:

the index of the first occurrence of the specified element in this vector, or -1 if this vector does not contain the element

indexOf

public int indexOf(Object o,
                   int index)

Returns the index of the first occurrence of the specified element in this vector, searching forwards from index, or returns -1 if the element is not found. More formally, returns the lowest index i such that (i >= index && (o==null ? get(i)==null : o.equals(get(i)))), or -1 if there is no such index.

Parameters:

o - element to search for

index - index to start searching from

Returns:

the index of the first occurrence of the element in this vector at position index or later in the vector; -1 if the element is not found.

Throws:

IndexOutOfBoundsException - if the specified index is negative

See Also:

Object.equals(Object)

lastIndexOf

public int lastIndexOf(Object o)

Returns the index of the last occurrence of the specified element in this vector, or -1 if this vector does not contain the 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.

Specified by:

lastIndexOf in interface List<E>

Overrides:

lastIndexOf in class AbstractList<E>

Parameters:

o - element to search for

Returns:

the index of the last occurrence of the specified element in this vector, or -1 if this vector does not contain the element

lastIndexOf

public int lastIndexOf(Object o,
                       int index)

Returns the index of the last occurrence of the specified element in this vector, searching backwards from index, or returns -1 if the element is not found. More formally, returns the highest index i such that (i <= index && (o==null ? get(i)==null : o.equals(get(i)))), or -1 if there is no such index.

Parameters:

o - element to search for

index - index to start searching backwards from

Returns:

the index of the last occurrence of the element at position less than or equal to index in this vector; -1 if the element is not found.

Throws:

IndexOutOfBoundsException - if the specified index is greater than or equal to the current size of this vector

elementAt

public E elementAt(int index)

Returns the component at the specified index.

This method is identical in functionality to the get(int) method (which is part of the List interface).

Parameters:

index - an index into this vector

Returns:

the component at the specified index

Throws:

ArrayIndexOutOfBoundsException - if the index is out of range (index < 0 || index >= size())

firstElement

public E firstElement()

Returns the first component (the item at index 0) of this vector.

Returns:

the first component of this vector

Throws:

NoSuchElementException - if this vector has no components

lastElement

public E lastElement()

Returns the last component of the vector.

Returns:

the last component of the vector, i.e., the component at index size() - 1.

Throws:

NoSuchElementException - if this vector is empty

setElementAt

public void setElementAt(E obj,
                         int index)

Sets the component at the specified index of this vector to be the specified object. The previous component at that position is discarded.

The index must be a value greater than or equal to 0 and less than the current size of the vector.

This method is identical in functionality to the set(int, E) method (which is part of the List interface). Note that the set method reverses the order of the parameters, to more closely match array usage. Note also that the set method returns the old value that was stored at the specified position.

Parameters:

obj - what the component is to be set to

index - the specified index

Throws:

ArrayIndexOutOfBoundsException - if the index is out of range (index < 0 || index >= size())

removeElementAt

public void removeElementAt(int index)

Deletes the component at the specified index. Each component in this vector with an index greater or equal to the specified index is shifted downward to have an index one smaller than the value it had previously. The size of this vector is decreased by 1.

The index must be a value greater than or equal to 0 and less than the current size of the vector.

This method is identical in functionality to the remove(int) method (which is part of the List interface). Note that the remove method returns the old value that was stored at the specified position.

Parameters:

index - the index of the object to remove

Throws:

ArrayIndexOutOfBoundsException - if the index is out of range (index < 0 || index >= size())

insertElementAt

public void insertElementAt(E obj,
                            int index)

Inserts the specified object as a component in this vector at the specified index. Each component in this vector with an index greater or equal to the specified index is shifted upward to have an index one greater than the value it had previously.

The index must be a value greater than or equal to 0 and less than or equal to the current size of the vector. (If the index is equal to the current size of the vector, the new element is appended to the Vector.)

This method is identical in functionality to the add(int, E) method (which is part of the List interface). Note that the add method reverses the order of the parameters, to more closely match array usage.

Parameters:

obj - the component to insert

index - where to insert the new component

Throws:

ArrayIndexOutOfBoundsException - if the index is out of range (index < 0 || index > size())

addElement

public void addElement(E obj)

Adds the specified component to the end of this vector, increasing its size by one. The capacity of this vector is increased if its size becomes greater than its capacity.

This method is identical in functionality to the add(E) method (which is part of the List interface).

Parameters:

obj - the component to be added

removeElement

public boolean removeElement(Object obj)

Removes the first (lowest-indexed) occurrence of the argument from this vector. If the object is found in this vector, each component in the vector with an index greater or equal to the object's index is shifted downward to have an index one smaller than the value it had previously.

This method is identical in functionality to the remove(Object) method (which is part of the List interface).

Parameters:

obj - the component to be removed

Returns:

true if the argument was a component of this vector; false otherwise.

removeAllElements

public void removeAllElements()

Removes all components from this vector and sets its size to zero.

This method is identical in functionality to the clear() method (which is part of the List interface).

clone

public Object clone()

Returns a clone of this vector. The copy will contain a reference to a clone of the internal data array, not a reference to the original internal data array of this Vector object.

Overrides:

clone in class Object

Returns:

a clone of this vector

See Also:

Cloneable

toArray

public Object[] toArray()

Returns an array containing all of the elements in this Vector in the correct order.

Specified by:

toArray in interface Collection<E>

Specified by:

toArray in interface List<E>

Overrides:

toArray in class AbstractCollection<E>

Returns:

an array containing all of the elements in this collection

Since:

1.2

See Also:

Arrays.asList(Object[])

toArray

public <T> T[] toArray(T[] a)

Returns an array containing all of the elements in this Vector in the correct order; the runtime type of the returned array is that of the specified array. If the Vector fits in the specified array, it is returned therein. Otherwise, a new array is allocated with the runtime type of the specified array and the size of this Vector.

If the Vector fits in the specified array with room to spare (i.e., the array has more elements than the Vector), the element in the array immediately following the end of the Vector is set to null. (This is useful in determining the length of the Vector only if the caller knows that the Vector does not contain any null elements.)

Specified by:

toArray in interface Collection<E>

Specified by:

toArray in interface List<E>

Overrides:

toArray in class AbstractCollection<E>

Parameters:

a - the array into which the elements of the Vector 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 the Vector

Throws:

ArrayStoreException - if the runtime type of a is not a supertype of the runtime type of every element in this Vector

NullPointerException - if the given array is null

Since:

1.2

get

public E get(int index)

Returns the element at the specified position in this Vector.

Specified by:

get in interface List<E>

Specified by:

get in class AbstractList<E>

Parameters:

index - index of the element to return

Returns:

object at the specified index

Throws:

ArrayIndexOutOfBoundsException - if the index is out of range (index < 0 || index >= size())

Since:

1.2

set

public E set(int index,
             E element)

Replaces the element at the specified position in this Vector with the specified element.

Specified by:

set in interface List<E>

Overrides:

set in class AbstractList<E>

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:

ArrayIndexOutOfBoundsException - if the index is out of range (index < 0 || index >= size())

Since:

1.2

add

public boolean add(E e)

Appends the specified element to the end of this Vector.

Specified by:

add in interface Collection<E>

Specified by:

add in interface List<E>

Overrides:

add in class AbstractList<E>

Parameters:

e - element to be appended to this Vector

Returns:

true (as specified by Collection.add(E))

Since:

1.2

remove

public boolean remove(Object o)

Removes the first occurrence of the specified element in this Vector If the Vector 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 in interface Collection<E>

Specified by:

remove in interface List<E>

Overrides:

remove in class AbstractCollection<E>

Parameters:

o - element to be removed from this Vector, if present

Returns:

true if the Vector contained the specified element

Since:

1.2

add

public void add(int index,
                E element)

Inserts the specified element at the specified position in this Vector. Shifts the element currently at that position (if any) and any subsequent elements to the right (adds one to their indices).

Specified by:

add in interface List<E>

Overrides:

add in class AbstractList<E>

Parameters:

index - index at which the specified element is to be inserted

element - element to be inserted

Throws:

ArrayIndexOutOfBoundsException - if the index is out of range (index < 0 || index > size())

Since:

1.2

remove

public E remove(int index)

Removes the element at the specified position in this Vector. Shifts any subsequent elements to the left (subtracts one from their indices). Returns the element that was removed from the Vector.

Specified by:

remove in interface List<E>

Overrides:

remove in class AbstractList<E>

Parameters:

index - the index of the element to be removed

Returns:

element that was removed

Throws:

ArrayIndexOutOfBoundsException - if the index is out of range (index < 0 || index >= size())

Since:

1.2

clear

public void clear()

Removes all of the elements from this Vector. The Vector will be empty after this call returns (unless it throws an exception).

Specified by:

clear in interface Collection<E>

Specified by:

clear in interface List<E>

Overrides:

clear in class AbstractList<E>

Since:

1.2

containsAll

public boolean containsAll(Collection<?> c)

Returns true if this Vector contains all of the elements in the specified Collection.

Specified by:

containsAll in interface Collection<E>

Specified by:

containsAll in interface List<E>

Overrides:

containsAll in class AbstractCollection<E>

Parameters:

c - a collection whose elements will be tested for containment in this Vector

Returns:

true if this Vector contains all of the elements in the specified collection

Throws:

NullPointerException - if the specified collection is null

See Also:

AbstractCollection.contains(Object)

addAll

public boolean addAll(Collection<? extends E> c)

Appends all of the elements in the specified Collection to the end of this Vector, in the order that they are returned by the specified Collection's Iterator. The behavior of this operation is undefined if the specified Collection is modified while the operation is in progress. (This implies that the behavior of this call is undefined if the specified Collection is this Vector, and this Vector is nonempty.)

Specified by:

addAll in interface Collection<E>

Specified by:

addAll in interface List<E>

Overrides:

addAll in class AbstractCollection<E>

Parameters:

c - elements to be inserted into this Vector

Returns:

true if this Vector changed as a result of the call

Throws:

NullPointerException - if the specified collection is null

Since:

1.2

See Also:

AbstractCollection.add(Object)

removeAll

public boolean removeAll(Collection<?> c)

Removes from this Vector all of its elements that are contained in the specified Collection.

Specified by:

removeAll in interface Collection<E>

Specified by:

removeAll in interface List<E>

Overrides:

removeAll in class AbstractCollection<E>

Parameters:

c - a collection of elements to be removed from the Vector

Returns:

true if this Vector changed as a result of the call

Throws:

ClassCastException - if the types of one or more elements in this vector are incompatible with the specified collection (optional)

NullPointerException - if this vector contains one or more null elements and the specified collection does not support null elements (optional), or if the specified collection is null

Since:

1.2

See Also:

AbstractCollection.remove(Object), AbstractCollection.contains(Object)

retainAll

public boolean retainAll(Collection<?> c)

Retains only the elements in this Vector that are contained in the specified Collection. In other words, removes from this Vector all of its elements that are not contained in the specified Collection.

Specified by:

retainAll in interface Collection<E>

Specified by:

retainAll in interface List<E>

Overrides:

retainAll in class AbstractCollection<E>

Parameters:

c - a collection of elements to be retained in this Vector (all other elements are removed)

Returns:

true if this Vector changed as a result of the call

Throws:

ClassCastException - if the types of one or more elements in this vector are incompatible with the specified collection (optional)

NullPointerException - if this vector contains one or more null elements and the specified collection does not support null elements (optional), or if the specified collection is null

Since:

1.2

See Also:

AbstractCollection.remove(Object), AbstractCollection.contains(Object)

addAll

public boolean addAll(int index,
                      Collection<? extends E> c)

Inserts all of the elements in the specified Collection into this Vector at the specified position. 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 the Vector in the order that they are returned by the specified Collection's iterator.

Specified by:

addAll in interface List<E>

Overrides:

addAll in class AbstractList<E>

Parameters:

index - index at which to insert the first element from the specified collection

c - elements to be inserted into this Vector

Returns:

true if this Vector changed as a result of the call

Throws:

ArrayIndexOutOfBoundsException - if the index is out of range (index < 0 || index > size())

NullPointerException - if the specified collection is null

Since:

1.2

equals

public boolean equals(Object o)

Compares the specified Object with this Vector 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.

Specified by:

equals in interface Collection<E>

Specified by:

equals in interface List<E>

Overrides:

equals in class AbstractList<E>

Parameters:

o - the Object to be compared for equality with this Vector

Returns:

true if the specified Object is equal to this Vector

See Also:

Object.hashCode(), Hashtable

hashCode

public int hashCode()

Returns the hash code value for this Vector.

Specified by:

hashCode in interface Collection<E>

Specified by:

hashCode in interface List<E>

Overrides:

hashCode in class AbstractList<E>

Returns:

the hash code value for this list

See Also:

Object.equals(java.lang.Object), Hashtable

toString

public String toString()

Returns a string representation of this Vector, containing the String representation of each element.

Overrides:

toString in class AbstractCollection<E>

Returns:

a string representation of this collection

subList

public List<E> subList(int fromIndex,
                       int toIndex)

Returns a view of the portion of this List between 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 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 operating on 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 the List, or otherwise perturb it in such a fashion that iterations in progress may yield incorrect results.)

Specified by:

subList in interface List<E>

Overrides:

subList in class AbstractList<E>

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 - if an endpoint index value is out of range (fromIndex < 0 || toIndex > size)

IllegalArgumentException - if the endpoint indices are out of order (fromIndex > toIndex)

removeRange

protected void removeRange(int fromIndex,
                           int toIndex)

Removes from this List all of the elements whose index is between fromIndex, inclusive and toIndex, exclusive. Shifts any succeeding elements to the left (reduces their index). This call shortens the ArrayList by (toIndex - fromIndex) elements. (If toIndex==fromIndex, this operation has no effect.)

Overrides:

removeRange in class AbstractList<E>

Parameters:

fromIndex - index of first element to be removed

toIndex - index after last element to be removed