java.util.ArrayList Maven / Gradle / Ivy
/*
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files generated from it may be used to generate other informative
documentation, such as a unified set of documents of API signatures for
a platform that includes technologies expressed as Java APIs. The file
may also be used to produce "compilation stubs," which allow
applications to be compiled and validated for such platforms.
Any work generated from this file, such as unified javadocs or compiled
stub files, must be accompanied by this notice in its entirety.
This work corresponds to the API signatures of JSR 219: Foundation
Profile 1.1. In the event of a discrepency between this work and the
JSR 219 specification, which is available at
http://www.jcp.org/en/jsr/detail?id=219, the latter takes precedence.
*/
package java.util;
/**
* 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
* 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 to 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.
*
* This class is a member of the
*
* Java Collections Framework.
*
* @author Josh Bloch
* @version 1.25, 02/02/00
* @see Collection
* @see List
* @see LinkedList
* @see Vector
* @see Collections#synchronizedList(List)
* @since 1.2
*/
public class ArrayList extends AbstractList
implements List, RandomAccess, Cloneable, java.io.Serializable
{
private static final long serialVersionUID = 8683452581122892189L;
/**
* The size of the ArrayList (the number of elements it contains).
*
* @serial
*/
private int size;
/**
* Constructs an empty list with the specified initial capacity.
*
* @param initialCapacity the initial capacity of the list.
* @exception IllegalArgumentException if the specified initial capacity
* is negative
*/
public ArrayList(int initialCapacity) { }
/**
* Constructs an empty list with an initial capacity of ten.
*/
public ArrayList() { }
/**
* Constructs a list containing the elements of the specified
* collection, in the order they are returned by the collection's
* iterator. The ArrayList instance has an initial capacity of
* 110% the size of the specified collection.
*
* @param c the collection whose elements are to be placed into this list.
* @throws NullPointerException if the specified collection is null.
*/
public ArrayList(Collection c) { }
/**
* 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.
*/
public void trimToSize() { }
/**
* 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.
*
* @param minCapacity the desired minimum capacity.
*/
public void ensureCapacity(int minCapacity) { }
/**
* Returns the number of elements in this list.
*
* @return the number of elements in this list.
*/
public int size() {
return 0;
}
/**
* Tests if this list has no elements.
*
* @return true if this list has no elements;
* false otherwise.
*/
public boolean isEmpty() {
return false;
}
/**
* Returns true if this list contains the specified element.
*
* @param elem element whose presence in this List is to be tested.
* @return true if the specified element is present;
* false otherwise.
*/
public boolean contains(Object elem) {
return false;
}
/**
* Searches for the first occurence of the given argument, testing
* for equality using the equals method.
*
* @param elem an object.
* @return the index of the first occurrence of the argument in this
* list; returns -1 if the object is not found.
* @see Object#equals(Object)
*/
public int indexOf(Object elem) {
return 0;
}
/**
* Returns the index of the last occurrence of the specified object in
* this list.
*
* @param elem the desired element.
* @return the index of the last occurrence of the specified object in
* this list; returns -1 if the object is not found.
*/
public int lastIndexOf(Object elem) {
return 0;
}
/**
* Returns a shallow copy of this ArrayList instance. (The
* elements themselves are not copied.)
*
* @return a clone of this ArrayList instance.
*/
public Object clone() {
return null;
}
/**
* Returns an array containing all of the elements in this list
* in the correct order.
*
* @return an array containing all of the elements in this list
* in the correct order.
*/
public Object[] toArray() {
return null;
}
/**
* 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.
*
* @param 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.
* @return an array containing the elements of the list.
* @throws ArrayStoreException if the runtime type of a is not a supertype
* of the runtime type of every element in this list.
*/
public Object[] toArray(Object[] a) {
return null;
}
/**
* Returns the element at the specified position in this list.
*
* @param index index of element to return.
* @return the element at the specified position in this list.
* @throws IndexOutOfBoundsException if index is out of range (index
* < 0 || index >= size()).
*/
public Object get(int index) {
return null;
}
/**
* Replaces the element at the specified position in this list with
* the specified element.
*
* @param index index of element to replace.
* @param element element to be stored at the specified position.
* @return the element previously at the specified position.
* @throws IndexOutOfBoundsException if index out of range
* (index < 0 || index >= size()).
*/
public Object set(int index, Object element) {
return null;
}
/**
* Appends the specified element to the end of this list.
*
* @param o element to be appended to this list.
* @return true (as per the general contract of Collection.add).
*/
public boolean add(Object o) {
return false;
}
/**
* 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).
*
* @param index index at which the specified element is to be inserted.
* @param element element to be inserted.
* @throws IndexOutOfBoundsException if index is out of range
* (index < 0 || index > size()).
*/
public void add(int index, Object element) { }
/**
* Removes the element at the specified position in this list.
* Shifts any subsequent elements to the left (subtracts one from their
* indices).
*
* @param index the index of the element to removed.
* @return the element that was removed from the list.
* @throws IndexOutOfBoundsException if index out of range (index
* < 0 || index >= size()).
*/
public Object remove(int index) {
return null;
}
/**
* Removes all of the elements from this list. The list will
* be empty after this call returns.
*/
public void clear() { }
/**
* 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. 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 list, and this
* list is nonempty.)
*
* @param c the elements to be inserted into this list.
* @return true if this list changed as a result of the call.
* @throws NullPointerException if the specified collection is null.
*/
public boolean addAll(Collection c) {
return false;
}
/**
* Inserts all of the elements in the specified Collection into this
* list, starting 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 list in the order that they are returned by the
* specified Collection's iterator.
*
* @param index index at which to insert first element
* from the specified collection.
* @param c elements to be inserted into this list.
* @return true if this list changed as a result of the call.
* @throws IndexOutOfBoundsException if index out of range (index
* < 0 || index > size()).
* @throws NullPointerException if the specified Collection is null.
*/
public boolean addAll(int index, Collection c) {
return false;
}
/**
* 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.)
*
* @param fromIndex index of first element to be removed.
* @param toIndex index after last element to be removed.
*/
protected void removeRange(int fromIndex, int toIndex) { }
/**
* Reconstitute the ArrayList instance from a stream (that is,
* deserialize it).
*/
private void readObject(java.io.ObjectInputStream s)
throws java.io.IOException, ClassNotFoundException
{ }
/**
* Save the state of the ArrayList instance to a stream (that
* is, serialize it).
*
* @serialData The length of the array backing the ArrayList
* instance is emitted (int), followed by all of its elements
* (each an Object) in the proper order.
*/
private void writeObject(java.io.ObjectOutputStream s)
throws java.io.IOException
{ }
}