Lets have a look to make easy comparison among the Collection classes based on some important properties.
Properties
--------------------
Class
|
Versions
|
Null
insertion
|
Insertion
Order
|
Synchronized
|
Duplicate
Object
|
Data
Structure
|
Cursor
|
||
Enumeration
|
Iterator
|
List Iterator
|
|||||||
ArrayList
|
1.2v
|
Possible
|
Preserved
|
No
|
Allowed
|
Growable Array
|
No
|
Yes
|
Yes
|
LinkedList
|
1.2v
|
Possible
|
Preserved
|
No
|
Allowed
|
Double LinkedList
|
No
|
Yes
|
Yes
|
Vector
|
1.0v (legacy)
|
Possible
|
Preserved
|
Yes
|
Allowed
|
Growable Array
|
Yes
|
Yes
|
No
|
Stack
|
1.0v
|
Possible
|
Preserved
|
No
|
Allowed
|
Stack
|
Yes
|
Yes
|
No
|
HashSet
|
1.2v
|
Possible (once)
|
Not preserved
|
No
|
Not allowed
|
Hash set
|
No
|
Yes
|
No
|
LinkedHashSet
|
1.4v
|
Possible (once)
|
Preserved
|
No
|
Not allowed
|
HashSet & LinkedList
|
No
|
Yes
|
No
|
TreeSet
|
1.2v
|
Possible (once)
|
Not preserved
|
No
|
Not allowed
|
Balanced tree
|
No
|
Yes
|
No
|
HashMap
|
1.2v
|
Key possible (once)
Value (anytime)
|
Not preserved
|
No
|
Key not allowed (value allowed)
|
Hashtable
|
No
|
Yes
|
No
|
LinkedHashMap
|
1.4v
|
Key possible (once)
Value (anytime)
|
Preserved
|
No
|
Key not allowed (value allowed)
|
HashSet & LinkedList
|
No
|
Yes
|
No
|
TreeMap
|
1.2v
|
Key possible (once)
Value (anytime)
|
Not preserved
|
No
|
Key not allowed Value allowed
|
REDBLACK Tree
|
No
|
Yes
|
No
|
HashTable
|
1.0v (legacy)
|
Key and Value both not possible
|
Not preserved
|
Yes
|
Key and Value both allowed
|
Hashtable
|
Yes
|
Yes
|
No
|
