This abstract class is a partial implementation of the List interface that makes it easy to define List implementations based on a sequential-access data model, as is the case with the LinkedList subclass. To implement a List based on an array or other random-access model, subclass AbstractList instead.

To implement an unmodifiable list, subclass this class and override the size( ) and listIterator( ) methods. listIterator( ) must return a ListIterator that defines the hasNext( ), hasPrevious( ), next( ), previous( ), and index( ) methods. If you want to allow the list to be modified, the ListIterator should also support the set( ) method and, optionally, the add( ) and remove( ) methods. AbstractSequentialList implements all other List methods in terms of these methods. Some subclasses may want to override additional methods to improve performance. In addition, it is conventional that all List implementations define two constructors: one that accepts no arguments and another that accepts a Collection of initial elements for the list.

Figure 16-5. java.util.AbstractSequentialList<E>

public abstract class AbstractSequentialList<E> extends AbstractList<E> {
// Protected Constructors
     protected AbstractSequentialList( );  
// Public Methods Overriding AbstractList
     public void add(int index, E element);  
     public boolean addAll(int index, Collection<? extends E> c);  
     public E get(int index);  
     public Iterator<E> iterator( );  
     public abstract ListIterator<E> listIterator(int index);  
     public E remove(int index);  
     public E set(int index, E element);  
}

Subclasses

LinkedList