What_is_collection.htm
 
Collection, as goes the name, is a collection of chain of objects/elements having some kind of algorithm or sequence or pattern. Before it  used to store, retrieve, manipulate, and communicate aggregate data. Now there are included in the collection frame work .

The frame work contains

  • Interfaces:

  • Implementations: The aggregated objects are being inherited in a class that implements the interface as a part of polymorphism.
  • Algorithms:

 

Collection themes:
  • Initialization Patterns:
  • List<String> list = new ArrayList<String>(c);
  • LinkedHashMap <String, String> map1 =
    new LinkedHashMap <String, String>();
  • Set Interface : Can't have duplicate element,
    • Set Implementation: HashSet, TreeSet, LinkecHashSet.
    • HashSet: stores elements in HashTable, has no order of iteration.
    • TreeSet : orders element with their values
    • LinkedHashSet: follow the order of Insertions values
  • List an ordered collection (sometimes called a sequence).
  • Queue a collection used to hold multiple elements prior to processing.
  • Map If you've used Hashtable, you're already familiar with the basics of Map. Also see The Map Interface section from Oracle's site.
Interfaces Implementations
  Hash table Resizable array Tree Linked list Hash table + Linked list
Set HashSet   TreeSet   LinkedHashSet
List   ArrayList   LinkedList  
Queue          
Map HashMap   TreeMap   LinkedHashMap
 
This is from j2se.ocm
Interface Type Implemented by
Set HashSet, LinkedHashSet, EnumSet
SortedSet TreeSet
List Vector, Stack, ArrayList, LinkedList
Queue PriorityQueue, LinkedList
Map Hashtable, HashMap, LinkedHashMap, WeakHashMap, IdentityHashMap
SortedMap TreeMap

 

This was taken from Sun Micro corporation site to display the architectures of Collection.;
Method Summary
 boolean add(E e)
          Appends the specified element to the end of this list (optional operation).
 void add(int index, E element)
          Inserts the specified element at the specified position in this list (optional operation).
 boolean addAll(Collection<? extends E> c)
          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 (optional operation).
 boolean addAll(int index, Collection<? extends E> c)
          Inserts all of the elements in the specified collection into this list at the specified position (optional operation).
 void clear()
          Removes all of the elements from this list (optional operation).
 boolean contains(Object o)
          Returns true if this list contains the specified element.
 boolean containsAll(Collection<?> c)
          Returns true if this list contains all of the elements of the specified collection.
 boolean equals(Object o)
          Compares the specified object with this list for equality.
 E get(int index)
          Returns the element at the specified position in this list.
 int hashCode()
          Returns the hash code value for this list.
 int indexOf(Object o)
          Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element.
 boolean isEmpty()
          Returns true if this list contains no elements.
 Iterator<E> iterator()
          Returns an iterator over the elements in this list in proper sequence.
 int lastIndexOf(Object o)
          Returns the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element.
 ListIterator<E> listIterator()
          Returns a list iterator over the elements in this list (in proper sequence).
 ListIterator<E> listIterator(int index)
          Returns a list iterator of the elements in this list (in proper sequence), starting at the specified position in this list.
 E remove(int index)
          Removes the element at the specified position in this list (optional operation).
 boolean remove(Object o)
          Removes the first occurrence of the specified element from this list, if it is present (optional operation).
 boolean removeAll(Collection<?> c)
          Removes from this list all of its elements that are contained in the specified collection (optional operation).
 boolean retainAll(Collection<?> c)
          Retains only the elements in this list that are contained in the specified collection (optional operation).
 E set(int index, E element)
          Replaces the element at the specified position in this list with the specified element (optional operation).
 int size()
          Returns the number of elements in this list.
 List<E> subList(int fromIndex, int toIndex)
          Returns a view of the portion of this list between the specified fromIndex, inclusive, and toIndex, exclusive.
 Object[] toArray()
          Returns an array containing all of the elements in this list in proper sequence (from first to last element).
<T> T[]
toArray(T[] a)
          Returns an array containing all of the elements in this list in proper sequence (from first to last element); the runtime type of the returned array is that of the specified array.