java.util.Vector<E>
Vector is a variable size contiguous indexable array of Objects. The size of
the Vector is the number of Objects it contains. The capacity of the Vector
is the number of Objects it can hold.
Objects may be inserted at any position up to the size of the Vector,
increasing the size of the Vector. Objects at any position in the Vector may
be removed, shrinking the size of the Vector. Objects at any position in the
Vector may be replaced, which does not affect the Vector size.
The capacity of a Vector may be specified when the Vector is created. If the
capacity of the Vector is exceeded, the capacity is increased, doubling by
default.
Known Direct Subclasses
Stack<E> |
Stack is a Last-In/First-Out(LIFO) data structure which
represents a stack of objects. |
Summary
Fields
protected |
|
|
int |
capacityIncrement |
How many elements should be added to the vector when it is detected that
it needs to grow to accommodate extra entries. |
protected |
|
|
int |
elementCount |
The number of elements or the size of the vector. |
protected |
|
|
Object[] |
elementData |
The elements of the vector. |
Public Constructors
Public Methods
Protected Methods
add,
add,
addAll,
clear,
equals,
get,
hashCode,
indexOf,
iterator,
lastIndexOf,
listIterator,
listIterator,
remove,
removeRange,
set,
subList
add,
addAll,
clear,
contains,
containsAll,
isEmpty,
iterator,
remove,
removeAll,
retainAll,
size,
toArray,
toArray,
toString
clone,
equals,
finalize,
getClass,
hashCode,
notify,
notifyAll,
toString,
wait,
wait,
wait
add,
addAll,
clear,
contains,
containsAll,
equals,
hashCode,
isEmpty,
iterator,
remove,
removeAll,
retainAll,
size,
toArray,
toArray
Methods inherited
from interface
java.util.List
add,
add,
addAll,
addAll,
clear,
contains,
containsAll,
equals,
get,
hashCode,
indexOf,
isEmpty,
iterator,
lastIndexOf,
listIterator,
listIterator,
remove,
remove,
removeAll,
retainAll,
set,
size,
subList,
toArray,
toArray
Details
Fields
protected
int
capacityIncrement
How many elements should be added to the vector when it is detected that
it needs to grow to accommodate extra entries.
protected
int
elementCount
The number of elements or the size of the vector.
protected
Object[]
elementData
The elements of the vector.
Public Constructors
public
Vector()
Constructs a new Vector using the default capacity.
public
Vector(int capacity)
Constructs a new Vector using the specified capacity.
Parameters
capacity
| the initial capacity of the new vector
|
public
Vector(int capacity, int capacityIncrement)
Constructs a new Vector using the specified capacity and capacity
increment.
Parameters
capacity
| the initial capacity of the new Vector |
capacityIncrement
| the amount to increase the capacity when this Vector is full
|
public
Vector(Collection<? extends E> collection)
Constructs a new instance of
Vector
containing the
elements in
collection
. The order of the elements in the
new
Vector
is dependent on the iteration order of the seed
collection.
Parameters
collection
| the collection of elements to add
|
Public Methods
public
void
add(int location, E object)
Adds the specified object into this Vector at the specified location. The
object is inserted before any previous element at the specified location.
If the location is equal to the size of this Vector, the object is added
at the end.
Parameters
location
| the index at which to insert the element |
object
| the object to insert in this Vector |
public
boolean
add(E object)
Adds the specified object at the end of this Vector.
Parameters
object
| the object to add to the Vector |
public
synchronized
boolean
addAll(int location, Collection<? extends E> collection)
Inserts the objects in the specified Collection at the specified location
in this Vector. The objects are inserted in the order in which they are
returned from the Collection iterator.
Parameters
location
| the location to insert the objects |
collection
| the Collection of objects |
Returns
- true if this Vector is modified, false otherwise
public
synchronized
boolean
addAll(Collection<? extends E> collection)
Adds the objects in the specified Collection to the end of this Vector.
Parameters
collection
| the Collection of objects |
Returns
- true if this Vector is modified, false otherwise
public
synchronized
void
addElement(E object)
Adds the specified object at the end of this Vector.
Parameters
object
| the object to add to the Vector
|
public
synchronized
int
capacity()
Returns the number of elements this Vector can hold without growing.
Returns
- the capacity of this Vector
public
void
clear()
Removes all elements from this Vector, leaving it empty.
public
synchronized
Object
clone()
Returns a new Vector with the same elements, size, capacity and capacity
increment as this Vector.
Returns
- a shallow copy of this Vector
public
boolean
contains(Object object)
Searches this Vector for the specified object.
Parameters
object
| the object to look for in this Vector |
Returns
- true if object is an element of this Vector, false otherwise
public
synchronized
boolean
containsAll(Collection<?> collection)
Searches this Vector for all objects in the specified Collection.
Parameters
collection
| the Collection of objects |
Returns
- true if all objects in the specified Collection are elements of
this Vector, false otherwise
public
synchronized
void
copyInto(Object[] elements)
Attempts to copy elements contained by this
Vector
into
the corresponding elements of the supplied
Object
array.
Parameters
elements
| the Object array into which the elements of
this Vector are copied |
public
synchronized
E
elementAt(int location)
Returns the element at the specified location in this Vector.
Parameters
location
| the index of the element to return in this Vector |
Returns
- the element at the specified location
Returns an Enumeration on the elements of this Vector. The results of the
Enumeration may be affected if the contents of this Vector are modified.
Returns
- an Enumeration of the elements of this Vector
public
synchronized
void
ensureCapacity(int minimumCapacity)
Ensures that this Vector can hold the specified number of elements
without growing.
Parameters
minimumCapacity
| the minimum number of elements that this vector will hold
before growing |
public
synchronized
boolean
equals(Object object)
Compares the specified object to this Vector and answer if they are
equal. The object must be a List which contains the same objects in the
same order.
Parameters
object
| the object to compare with this object |
Returns
- true if the specified object is equal to this Vector, false
otherwise
public
synchronized
E
firstElement()
Returns the first element in this Vector.
Returns
- the element at the first position
public
synchronized
E
get(int location)
Returns the element at the specified location in this Vector.
Parameters
location
| the index of the element to return in this Vector |
Returns
- the element at the specified location
public
synchronized
int
hashCode()
Returns an integer hash code for the receiver. Objects which are equal
answer the same value for this method.
public
int
indexOf(Object object)
Searches in this Vector for the index of the specified object. The search
for the object starts at the beginning and moves towards the end of this
Vector.
Parameters
object
| the object to find in this Vector |
Returns
- the index in this Vector of the specified element, -1 if the
element isn't found
public
synchronized
int
indexOf(Object object, int location)
Searches in this Vector for the index of the specified object. The search
for the object starts at the specified location and moves towards the end
of this Vector.
Parameters
object
| the object to find in this Vector |
location
| the index at which to start searching |
Returns
- the index in this Vector of the specified element, -1 if the
element isn't found
public
synchronized
void
insertElementAt(E object, int location)
Inserts the specified object into this Vector at the specified location.
This object is inserted before any previous element at the specified
location. If the location is equal to the size of this Vector, the object
is added at the end.
Parameters
object
| the object to insert in this Vector |
location
| the index at which to insert the element |
public
synchronized
boolean
isEmpty()
Returns if this Vector has no elements, a size of zero.
Returns
- true if this Vector has no elements, false otherwise
public
synchronized
E
lastElement()
Returns the last element in this Vector.
Returns
- the element at the last position
public
synchronized
int
lastIndexOf(Object object, int location)
Searches in this Vector for the index of the specified object. The search
for the object starts at the specified location and moves towards the
start of this Vector.
Parameters
object
| the object to find in this Vector |
location
| the index at which to start searching |
Returns
- the index in this Vector of the specified element, -1 if the
element isn't found
public
synchronized
int
lastIndexOf(Object object)
Searches in this Vector for the index of the specified object. The search
for the object starts at the end and moves towards the start of this
Vector.
Parameters
object
| the object to find in this Vector |
Returns
- the index in this Vector of the specified element, -1 if the
element isn't found
public
synchronized
E
remove(int location)
Removes the object at the specified location from this List.
Parameters
location
| the index of the object to remove |
public
boolean
remove(Object object)
Removes the first occurrence, starting at the beginning and moving
towards the end, of the specified object from this Vector.
Parameters
object
| the object to remove from this Vector |
Returns
- true if the specified object was found, false otherwise
public
synchronized
boolean
removeAll(Collection<?> collection)
Removes all occurrences in this Vector of each object in the specified
Collection.
Parameters
collection
| the Collection of objects to remove |
Returns
- true if this Vector is modified, false otherwise
public
synchronized
void
removeAllElements()
Removes all elements from this Vector, leaving the size zero and the
capacity unchanged.
public
synchronized
boolean
removeElement(Object object)
Removes the first occurrence, starting at the beginning and moving
towards the end, of the specified object from this Vector.
Parameters
object
| the object to remove from this Vector |
Returns
- true if the specified object was found, false otherwise
public
synchronized
void
removeElementAt(int location)
Removes the element found at index position
location
from
this
Vector
and decrements the size accordingly.
Parameters
location
| the index of the element to remove |
public
synchronized
boolean
retainAll(Collection<?> collection)
Removes all objects from this Vector that are not contained in the
specified Collection.
Parameters
collection
| the Collection of objects to retain |
Returns
- true if this Vector is modified, false otherwise
public
synchronized
E
set(int location, E object)
Replaces the element at the specified location in this Vector with the
specified object.
Parameters
location
| the index at which to put the specified object |
object
| the object to add to this Vector |
Returns
- the previous element at the location
public
synchronized
void
setElementAt(E object, int location)
Replaces the element at the specified location in this Vector with the
specified object.
Parameters
object
| the object to add to this Vector |
location
| the index at which to put the specified object |
public
synchronized
void
setSize(int length)
Sets the size of this Vector to the specified size. If there are more
than length elements in this Vector, the elements at end are lost. If
there are less than length elements in the Vector, the additional
elements contain null.
Parameters
length
| the new size of this Vector |
public
synchronized
int
size()
Returns the number of elements in this Vector.
Returns
- the number of elements in this Vector
public
synchronized
List<E>
subList(int start, int end)
Returns a List of the specified portion of this Vector from the start
index to one less than the end index. The returned List is backed by this
Vector so changes to one are reflected by the other.
Parameters
start
| the index at which to start the sublist |
end
| the index one past the end of the sublist |
Returns
- a List of a portion of this Vector
public
synchronized
T[]
toArray(T[] contents)
Returns an array containing all elements contained in this Vector. If the
specified array is large enough to hold the elements, the specified array
is used, otherwise an array of the same type is created. If the specified
array is used and is larger than this Vector, the array element following
the collection elements is set to null.
Returns
- an array of the elements from this Vector
Throws
ArrayStoreException
| when the type of an element in this Vector cannot be
stored in the type of the specified array
|
public
synchronized
Object[]
toArray()
Returns a new array containing all elements contained in this Vector.
Returns
- an array of the elements from this Vector
public
synchronized
String
toString()
Returns the string representation of this Vector.
Returns
- the string representation of this Vector
public
synchronized
void
trimToSize()
Sets the capacity of this Vector to be the same as the size.
Protected Methods
protected
void
removeRange(int start, int end)
Removes the objects in the specified range from the start to the, but not
including, end index.
Parameters
start
| the index at which to start removing |
end
| the index one past the end of the range to remove |