java.util: abstract public class: AbstractSequentialList

java.util
abstract public class: AbstractSequentialList [javadoc | source]

java.lang.Object
   java.util.AbstractCollection
      java.util.AbstractList
         java.util.AbstractSequentialList

All Implemented Interfaces:
List, Collection

Direct Known Subclasses:
LinkedList

This class provides a skeletal implementation of the List interface to minimize the effort required to implement this interface backed by a "sequential access" data store (such as a linked list). For random access data (such as an array), AbstractList should be used in preference to this class.

This class is the opposite of the AbstractList class in the sense that it implements the "random access" methods (get(int index), set(int index, E element), add(int index, E element) and remove(int index)) on top of the list's list iterator, instead of the other way around.

To implement a list the programmer needs only to extend this class and provide implementations for the listIterator and size methods. For an unmodifiable list, the programmer need only implement the list iterator's hasNext, next, hasPrevious, previous and index methods.

For a modifiable list the programmer should additionally implement the list iterator's set method. For a variable-size list the programmer should additionally implement the list iterator's remove and add methods.

The programmer should generally provide a void (no argument) and collection constructor, as per the recommendation in the Collection interface specification.

This class is a member of the Java Collections Framework.

Also see:

author: Josh - Bloch

author: Neal - Gafter

since: 1.2 -

Fields inherited from java.util.AbstractList:
modCount

Constructor:
protected AbstractSequentialList() { } Sole constructor. (For invocation by subclass constructors, typically implicit.)

Constructor:

 protected AbstractSequentialList() {

}

Sole constructor. (For invocation by subclass constructors, typically implicit.)

Method from java.util.AbstractSequentialList Summary:
add, addAll, get, iterator, listIterator, remove, set

Methods from java.util.AbstractList:
add, add, addAll, clear, equals, get, hashCode, indexOf, iterator, lastIndexOf, listIterator, listIterator, remove, removeRange, set, subList

Methods from java.util.AbstractCollection:
add, addAll, clear, contains, containsAll, isEmpty, iterator, remove, removeAll, retainAll, size, toArray, toArray, toString

Methods from java.lang.Object:
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from java.util.AbstractSequentialList Detail:
public void add(int index, E element) { try { listIterator(index).add(element); } catch (NoSuchElementException exc) { throw new IndexOutOfBoundsException("Index: "+index); } } Inserts the specified element at the specified position in this list (optional operation). Shifts the element currently at that position (if any) and any subsequent elements to the right (adds one to their indices). This implementation first gets a list iterator pointing to the indexed element (with `listIterator(index)`). Then, it inserts the specified element with `ListIterator.add`. Note that this implementation will throw an `UnsupportedOperationException` if the list iterator does not implement the `add` operation.
public boolean addAll(int index, Collection c) { try { boolean modified = false; ListIterator< E > e1 = listIterator(index); Iterator< ? extends E > e2 = c.iterator(); while (e2.hasNext()) { e1.add(e2.next()); modified = true; } return modified; } catch (NoSuchElementException exc) { throw new IndexOutOfBoundsException("Index: "+index); } } Inserts all of the elements in the specified collection into this list at the specified position (optional operation). 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 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. (Note that this will occur if the specified collection is this list, and it's nonempty.) This implementation gets an iterator over the specified collection and a list iterator over this list pointing to the indexed element (with `listIterator(index)`). Then, it iterates over the specified collection, inserting the elements obtained from the iterator into this list, one at a time, using `ListIterator.add` followed by `ListIterator.next` (to skip over the added element). Note that this implementation will throw an `UnsupportedOperationException` if the list iterator returned by the `listIterator` method does not implement the `add` operation.
public E get(int index) { try { return listIterator(index).next(); } catch (NoSuchElementException exc) { throw new IndexOutOfBoundsException("Index: "+index); } } Returns the element at the specified position in this list. This implementation first gets a list iterator pointing to the indexed element (with `listIterator(index)`). Then, it gets the element using `ListIterator.next` and returns it.
public Iterator iterator() { return listIterator(); } Returns an iterator over the elements in this list (in proper sequence). This implementation merely returns a list iterator over the list.
abstract public ListIterator listIterator(int index) Returns a list iterator over the elements in this list (in proper sequence).
public E remove(int index) { try { ListIterator< E > e = listIterator(index); E outCast = e.next(); e.remove(); return outCast; } catch (NoSuchElementException exc) { throw new IndexOutOfBoundsException("Index: "+index); } } Removes the element at the specified position in this list (optional operation). Shifts any subsequent elements to the left (subtracts one from their indices). Returns the element that was removed from the list. This implementation first gets a list iterator pointing to the indexed element (with `listIterator(index)`). Then, it removes the element with `ListIterator.remove`. Note that this implementation will throw an `UnsupportedOperationException` if the list iterator does not implement the `remove` operation.
public E set(int index, E element) { try { ListIterator< E > e = listIterator(index); E oldVal = e.next(); e.set(element); return oldVal; } catch (NoSuchElementException exc) { throw new IndexOutOfBoundsException("Index: "+index); } } Replaces the element at the specified position in this list with the specified element (optional operation). This implementation first gets a list iterator pointing to the indexed element (with `listIterator(index)`). Then, it gets the current element using `ListIterator.next` and replaces it with `ListIterator.set`. Note that this implementation will throw an `UnsupportedOperationException` if the list iterator does not implement the `set` operation.

Method from java.util.AbstractSequentialList Detail:

 public  void add(int index,
    E element) {
        try {
            listIterator(index).add(element);
        } catch (NoSuchElementException exc) {
            throw new IndexOutOfBoundsException("Index: "+index);
        }
}

This implementation first gets a list iterator pointing to the indexed element (with listIterator(index)). Then, it inserts the specified element with ListIterator.add.

Note that this implementation will throw an UnsupportedOperationException if the list iterator does not implement the add operation.

 public boolean addAll(int index,
    Collection c) {
        try {
            boolean modified = false;
            ListIterator< E > e1 = listIterator(index);
            Iterator< ? extends E > e2 = c.iterator();
            while (e2.hasNext()) {
                e1.add(e2.next());
                modified = true;
            }
            return modified;
        } catch (NoSuchElementException exc) {
            throw new IndexOutOfBoundsException("Index: "+index);
        }
}

This implementation gets an iterator over the specified collection and a list iterator over this list pointing to the indexed element (with listIterator(index)). Then, it iterates over the specified collection, inserting the elements obtained from the iterator into this list, one at a time, using ListIterator.add followed by ListIterator.next (to skip over the added element).

Note that this implementation will throw an UnsupportedOperationException if the list iterator returned by the listIterator method does not implement the add operation.

 public E get(int index) {
        try {
            return listIterator(index).next();
        } catch (NoSuchElementException exc) {
            throw new IndexOutOfBoundsException("Index: "+index);
        }
}

This implementation first gets a list iterator pointing to the indexed element (with listIterator(index)). Then, it gets the element using ListIterator.next and returns it.

 public Iterator iterator() {
        return listIterator();
}

This implementation merely returns a list iterator over the list.

 abstract public ListIterator listIterator(int index)Returns a list iterator over the elements in this list (in proper
sequence).

 public E remove(int index) {
        try {
            ListIterator< E > e = listIterator(index);
            E outCast = e.next();
            e.remove();
            return outCast;
        } catch (NoSuchElementException exc) {
            throw new IndexOutOfBoundsException("Index: "+index);
        }
}

This implementation first gets a list iterator pointing to the indexed element (with listIterator(index)). Then, it removes the element with ListIterator.remove.

Note that this implementation will throw an UnsupportedOperationException if the list iterator does not implement the remove operation.

 public E set(int index,
    E element) {
        try {
            ListIterator< E > e = listIterator(index);
            E oldVal = e.next();
            e.set(element);
            return oldVal;
        } catch (NoSuchElementException exc) {
            throw new IndexOutOfBoundsException("Index: "+index);
        }
}

This implementation first gets a list iterator pointing to the indexed element (with listIterator(index)). Then, it gets the current element using ListIterator.next and replaces it with ListIterator.set.

Note that this implementation will throw an UnsupportedOperationException if the list iterator does not implement the set operation.