freaklamarsch.util
Class FLMResizableArray

java.lang.Object
  |
  +--freaklamarsch.util.FLMResizableArray

public class FLMResizableArray
extends java.lang.Object

Resizable-array implementation of the List interface. Implements all optional list operations, and permits all elements, including null. In addition to implementing the List interface, this class provides methods to manipulate the size of the array that is used internally to store the list. (This class is roughly equivalent to java.util.Vector, except that it is unsynchronized.)

The size, isEmpty, get, set, iterator, and listIterator operations run in constant time. The add operation runs in amortized constant time, that is, adding n elements requires O(n) time. All of the other operations run in linear time (roughly speaking). The constant factor is low compared to that for the LinkedList implementation.

Each ArrayList instance has a capacity. The capacity is the size of the array used to store the elements in the list. It is always at least as large as the list size. As elements are added an ArrayList, its capacity grows automatically. The details of the growth policy are not specified beyond the fact that adding an element has constant amortized time cost.

An application can increase the capacity of an ArrayList instance before adding a large number of elements using the ensureCapacity operation. This may reduce the amount of incremental reallocation.

Note that this implementation is not synchronized. If multiple threads access an ArrayList instance concurrently, and at least one of the threads modifies the list structurally, it must be synchronized externally. (A structural modification is any operation that adds or deletes one or more elements, or explicitly resizes the backing array; merely setting the value of an element is not a structural modification.) This is typically accomplished by synchronizing on some object that naturally encapsulates the list. If no such object exists, the list should be "wrapped" using the Collections.synchronizedList method. This is best done at creation time, to prevent accidental unsynchronized access to the list:

	List list = Collections.synchronizedList(new ArrayList(...));
 

The iterators returned by this class's iterator and listIterator methods are fail-fast: if list 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.

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.


Constructor Summary
FLMResizableArray()
          Constructs an empty list with an initial capacity of ten.
FLMResizableArray(int initialCapacity)
          Constructs an empty list with the specified initial capacity.
 
Method Summary
 void add(int index, java.lang.Object element)
          Inserts the specified element at the specified position in this list.
 boolean add(java.lang.Object o)
          Appends the specified element to the end of this list.
 void clear()
          Removes all of the elements from this list.
 boolean contains(java.lang.Object elem)
          Returns true if this list contains the specified element.
 void copyInto(java.lang.Object[] anArray)
          Copies the components of this vector into the specified array.
 void ensureCapacity(int minCapacity)
          Increases the capacity of this ArrayList instance, if necessary, to ensure that it can hold at least the number of elements specified by the minimum capacity argument.
 java.lang.Object get(int index)
          Returns the element at the specified position in this list.
 int indexOf(java.lang.Object elem)
          Searches for the first occurence of the given argument, testing for equality using the equals method.
 boolean isEmpty()
          Tests if this list has no elements.
 int lastIndexOf(java.lang.Object elem)
          Returns the index of the last occurrence of the specified object in this list.
 java.lang.Object remove(int index)
          Removes the element at the specified position in this list.
protected  void removeRange(int fromIndex, int toIndex)
          Removes from this List all of the elements whose index is between fromIndex, inclusive and toIndex, exclusive.
 java.lang.Object set(int index, java.lang.Object element)
          Replaces the element at the specified position in this list with the specified element.
 int size()
          Returns the number of elements in this list.
 java.lang.Object[] toArray()
          Returns an array containing all of the elements in this list in the correct order.
 java.lang.Object[] toArray(java.lang.Object[] a)
          Returns an array containing all of the elements in this list in the correct order; the runtime type of the returned array is that of the specified array.
 void trimToSize()
          Trims the capacity of this ArrayList instance to be the list's current size.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

FLMResizableArray

public FLMResizableArray(int initialCapacity)
Constructs an empty list with the specified initial capacity.

Parameters:
initialCapacity - the initial capacity of the list.
Throws:
java.lang.IllegalArgumentException - if the specified initial capacity is negative

FLMResizableArray

public FLMResizableArray()
Constructs an empty list with an initial capacity of ten.

Method Detail

trimToSize

public void trimToSize()
Trims the capacity of this ArrayList instance to be the list's current size. An application can use this operation to minimize the storage of an ArrayList instance.


ensureCapacity

public void ensureCapacity(int minCapacity)
Increases the capacity of this ArrayList instance, if necessary, to ensure that it can hold at least the number of elements specified by the minimum capacity argument.

Parameters:
minCapacity - the desired minimum capacity.

size

public int size()
Returns the number of elements in this list.

Returns:
the number of elements in this list.

isEmpty

public boolean isEmpty()
Tests if this list has no elements.

Returns:
true if this list has no elements; false otherwise.

contains

public boolean contains(java.lang.Object elem)
Returns true if this list contains the specified element.

Parameters:
elem - element whose presence in this List is to be tested.
Returns:
true if the specified element is present; false otherwise.

indexOf

public int indexOf(java.lang.Object elem)
Searches for the first occurence of the given argument, testing for equality using the equals method.

Parameters:
elem - an object.
Returns:
the index of the first occurrence of the argument in this list; returns -1 if the object is not found.
See Also:
Object.equals(Object)

lastIndexOf

public int lastIndexOf(java.lang.Object elem)
Returns the index of the last occurrence of the specified object in this list.

Parameters:
elem - the desired element.
Returns:
the index of the last occurrence of the specified object in this list; returns -1 if the object is not found.

toArray

public java.lang.Object[] toArray()
Returns an array containing all of the elements in this list in the correct order.

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

toArray

public java.lang.Object[] toArray(java.lang.Object[] a)
Returns an array containing all of the elements in this list in the correct order; the runtime type of the returned array is that of the specified array. If the list 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 list.

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

Parameters:
a - the array into which the elements of the 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 the list.
Throws:
java.lang.ArrayStoreException - if the runtime type of a is not a supertype of the runtime type of every element in this list.

get

public java.lang.Object 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:
java.lang.IndexOutOfBoundsException - if index is out of range (index < 0 || index >= size()).

set

public java.lang.Object set(int index,
                            java.lang.Object element)
Replaces the element at the specified position in this list with the specified element.

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:
java.lang.IndexOutOfBoundsException - if index out of range (index < 0 || index >= size()).

add

public boolean add(java.lang.Object o)
Appends the specified element to the end of this list.

Parameters:
o - element to be appended to this list.
Returns:
true (as per the general contract of Collection.add).

add

public void add(int index,
                java.lang.Object element)
Inserts the specified element at the specified position in this list. 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:
java.lang.IndexOutOfBoundsException - if index is out of range (index < 0 || index > size()).

remove

public java.lang.Object remove(int index)
Removes the element at the specified position in this list. Shifts any subsequent elements to the left (subtracts one from their indices).

Parameters:
index - the index of the element to removed.
Returns:
the element that was removed from the list.
Throws:
java.lang.IndexOutOfBoundsException - if index out of range (index < 0 || index >= size()).

clear

public void clear()
Removes all of the elements from this list. The list will be empty after this call returns.


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 list by (toIndex - fromIndex) elements. (If toIndex==fromIndex, this operation has no effect.)

Parameters:
fromIndex - index of first element to be removed.
toIndex - index after last element to be removed.

copyInto

public void copyInto(java.lang.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. The array must be big enough to hold all the objects in this vector, else an IndexOutOfBoundsException is thrown.

Parameters:
anArray - the array into which the components get copied.
Throws:
java.lang.NullPointerException - if the given array is null.