Question

By definition Linked List is a list that each element of it refers to the next element (and previous element if we are talkin about double linked list.)
http://en.wikipedia.org/wiki/Linked_list

However, in Java LinkedList is implementing List, Queue, Deque and more.
http://docs.oracle.com/javase/6/docs/api/java/util/LinkedList.html

You can not find a method in LinkedList that gives you next or previous object in the list, the best you can do is to get an Iterator and get objects. My question is why Java has called this data structure LinkedList, while it is not truly a linked list? A linked list can be implemented in Java like this:

Public class MyLinkedList{
 public int value;
 public MyLinkedList next;
}

Answer 1

My question is why Java has called this data structure LinkedList, while it is not truly a linked list?

Because the implementation of it is a linked list. From the documentation:

Doubly-linked list implementation of the List and Deque interfaces. Implements all optional list operations, and permits all elements (including null).

LinkedList is a List implemented via a linked-list, ArrayList is a List implemented using an array, etc. Which one you choose can matter in terms of runtime characteristics. For instance, from the LinkedList docs:

All of the operations perform as could be expected for a doubly-linked list. Operations that index into the list will traverse the list from the beginning or the end, whichever is closer to the specified index.

So you know, for instance, that next on the Iterator you get from iterator or listIterator will be quite efficient, but that get by index will involve traversal.