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Chapter 17 The java.util Package |
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Chapter 17 The java.util Package |
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java.util.Vector
java.lang.Object
java.util.Stack
java.io.Serializable, java.lang.Cloneable
JDK 1.0 or later
The Vector class implements a variable-length array that can hold any kind of object. Like an array, the elements in a Vector are accessed with an integer index. However, unlike an array, the size of a Vector can grow and shrink as needed to accommodate a changing number of objects. Vector provides methods to add and remove elements, as well as ways to search for objects in a Vector and iterate through all of the objects.
The initial capacity of a Vector specifies how many objects it can contain before more space must be allocated. The capacity increment specifies how much more space is allocated each time the Vector needs to increase its capacity. You can fine-tune the performance of a Vector by adjusting the initial capacity and capacity increment.
public class java.util.Vector extends java.lang.Object
implements java.io.Serializable, java.lang.Cloneable {
// Variables
protected int capacityIncrement;
protected int elementCount;
protected Object[] elementData;
// Constructors
public Vector();
public Vector(int initialCapacity);
public Vector(int initialCapacity, int capacityIncrement);
// Instance Methods
public final synchronized void addElement(Object obj);
public final int capacity();
public synchronized Object clone();
public final boolean contains(Object elem);
public final synchronized void copyInto(Object[] anArray);
public final synchronized Object elementAt(int index);
public final synchronized Enumeration elements();
public final synchronized void ensureCapacity(int minCapacity);
public final synchronized Object firstElement();
public final int indexOf(Object elem);
public final synchronized int indexOf(Object elem, int index);
public final synchronized void insertElementAt(Object obj, int index);
public final boolean isEmpty();
public final synchronized Object lastElement();
public final int lastIndexOf(Object elem);
public final synchronized int lastIndexOf(Object elem, int index);
public final synchronized void removeAllElements();
public final synchronized boolean removeElement(Object obj);
public final synchronized void removeElementAt(int index);
public final synchronized void setElementAt(Object obj, int index);
public final synchronized void setSize(int newSize);
public final int size();
public final synchronized String toString();
public final synchronized void trimToSize();
}
The amount by which the internal array grows when more space is needed. If the value is 0, the internal array doubles in size when more space is needed.
The count of how many objects are contained in this Vector.
The array that holds the contents of this Vector.
This constructor creates an empty Vector with the default capacity of 10 and the default capacity increment of 0.
The initial capacity of the Vector.
This constructor creates an empty Vector with the given capacity and the default capacity increment of 0.
The initial capacity of the Vector.
The amount to increase the capacity when more space is needed.
This constructor creates an empty Vector with the given capacity and capacity increment.
The object to be added.
This method adds the given object to this Vector as its last element and increases its size by 1. The capacity of the Vector is increased if its size becomes greater than its capacity. Any kind of object can be added to a Vector.
The capacity of this Vector.
This method returns the size of the internal array of this Vector.
A copy of this Vector.
Object.clone()
This method creates a copy of this Vector and returns it.
The object to be found.
true if the given object is contained in this Vector; false otherwise.
This method determines whether or not the given object is contained in this Vector.
The array to be filled.
If the given array is too small to hold all of the objects in this Vector.
This method copies the object references in this Vector to the given array.
The index of the object to be returned.
The object at the position given by index.
If index is less than zero or greater than the size of this Vector.
This method returns the object at the given index in this Vector.
The objects in this Vector as an Enumeration.
This method returns an Enumeration that iterates through the objects in this Vector.
The minimum new capacity.
This method expands the internal array, if necessary, to make the capacity of the Vector at least minCapacity.
The first object in this Vector.
If the Vector is empty.
This method returns the object at index 0 in this Vector.
The object to be found.
The index of the given object or -1 if it cannot be found.
This method returns the index of the first occurrence of the given object in this Vector.
The object to be found.
The starting index.
The index of the next occurrence of the given object after the specified index or -1 if it cannot be found.
This method returns the index of the next occurrence of the given object in this Vector after the given index.
The object to be inserted.
The index at which to insert the object.
If index is less than zero or greater than the size of this Vector.
This method inserts the given object at the given index in this Vector. Each object in the Vector with an index greater than or equal to index is shifted upward in the Vector, so that it has an index of one greater than it did previously.
true if there are no objects in the Vector; false otherwise.
This method returns a boolean value that indicates whether or not the Vector is empty.
The last object in this Vector.
If the Vector is empty.
This method returns the last object in this Vector.
The object to be found.
The index of the given object or -1 if it cannot be found.
This method returns the index of the last occurrence of the given object in this Vector.
The object to be found.
The starting index.
The index of the last occurrence of the given object before the specified index or -1 if it cannot be found.
This method returns the index of the last occurrence of the given object in this Vector before the given index. In other words, the method searches backwards from index for the next occurrence.
This method removes all of the objects from this Vector, but does not change its capacity or capacity increment.
The object to be removed.
true if the given object is found and removed; false otherwise.
This method searches for the first occurrence of the given object in this Vector and removes it. If the object is found, each object in the Vector with an index greater than or equal to the index of the removed object is shifted downward in the Vector, so that it has an index of one less than it did previously.
The index of the object to be removed.
If index is less than zero or greater than the size of this Vector.
This method removes the object at the given index from this Vector. Each object in the Vector with an index greater than or equal to index is shifted downward in the Vector, so that it has an index of one less than it did previously.
The object to be put in the Vector.
The index at which to put the object.
If index is less than zero or greater than the size of this Vector.
This method puts the given object at the given index in this Vector, replacing the object that was previously there.
The new size.
This method sets the size (not the capacity) of this Vector. If the new size is bigger than the current size, null elements are added to the end of the Vector. If the new size is smaller than the current size, elements are discarded from index newSize to the end of the Vector.
The size of this Vector.
This method returns the number of objects contained in this Vector.
A string that represents this Vector.
Object.toString()
This method returns a string representation of this Vector. The string includes every object that is contained in the Vector, so the string returned by toString() can be quite long.
This method sets the capacity of this Vector equal to its size. You can use this method to minimize the storage space used by the Vector, but any subsequent calls to addElement() or insertElement() forces the Vector to allocate more space.
| Method | Inherited From | Method | Inherited From |
|---|---|---|---|
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equals(Object) |
Object |
finalize() |
Object |
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getClass() |
Object |
hashCode() |
Object |
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notify() |
Object |
notifyAll() |
Object |
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wait() |
Object |
wait(long) |
Object |
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wait(long, int) |
Object |
ArrayIndexOutOfBoundsException, Cloneable, Enumeration, NoSuchElementException, Serializable, Stack
|
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| TooManyListenersException |  |
Adler32 |
