@GwtCompatible public abstract class ForwardingList<E> extends ForwardingCollection<E> implements List<E>
A list which forwards all its method calls to another list. Subclasses should override one or more methods to modify the behavior of the backing list as desired per the decorator pattern.
This class does not implement RandomAccess. If the delegate supports random access, the ForwardingList subclass should implement the RandomAccess interface.
Warning: The methods of ForwardingList forward indiscriminately to the methods of the delegate. For example, overriding add(int, E) alone will not change the behavior of addAll(int, java.util.Collection<? extends E>), which can lead to unexpected behavior. In this case, you should override addAll as well, either providing your own implementation, or delegating to the provided standardAddAll method.
The standard methods and any collection views they return are not guaranteed to be thread-safe, even when all of the methods that they depend on are thread-safe.
| Modifier | Constructor and Description |
|---|---|
protected |
ForwardingList()
Constructor for use by subclasses.
|
| Modifier and Type | Method and Description |
|---|---|
void |
add(int index,
E element) |
boolean |
addAll(int index,
Collection<? extends E> elements) |
protected abstract List<E> |
delegate()
Returns the backing delegate instance that methods are forwarded to.
|
boolean |
equals(Object object) |
E |
get(int index) |
int |
hashCode() |
int |
indexOf(Object element) |
int |
lastIndexOf(Object element) |
ListIterator<E> |
listIterator() |
ListIterator<E> |
listIterator(int index) |
E |
remove(int index) |
E |
set(int index,
E element) |
protected boolean |
standardAdd(E element)
A sensible default implementation of
ForwardingCollection.add(Object), in terms of add(int, Object). |
protected boolean |
standardAddAll(int index,
Iterable<? extends E> elements)
A sensible default implementation of
addAll(int, Collection), in terms of the add method of listIterator(int). |
protected boolean |
standardEquals(Object object)
A sensible definition of
equals(Object) in terms of ForwardingCollection.size() and ForwardingCollection.iterator(). |
protected int |
standardHashCode()
A sensible definition of
hashCode() in terms of ForwardingCollection.iterator(). |
protected int |
standardIndexOf(Object element)
A sensible default implementation of
indexOf(java.lang.Object), in terms of listIterator(). |
protected Iterator<E> |
standardIterator()
A sensible default implementation of
ForwardingCollection.iterator(), in terms of listIterator(). |
protected int |
standardLastIndexOf(Object element)
A sensible default implementation of
lastIndexOf(java.lang.Object), in terms of listIterator(int). |
protected ListIterator<E> |
standardListIterator()
A sensible default implementation of
listIterator(), in terms of listIterator(int). |
protected ListIterator<E> |
standardListIterator(int start)
A sensible default implementation of
listIterator(int), in terms of ForwardingCollection.size(), get(int), set(int, Object), add(int, Object), and remove(int). |
protected List<E> |
standardSubList(int fromIndex,
int toIndex)
A sensible default implementation of
subList(int, int). |
List<E> |
subList(int fromIndex,
int toIndex) |
add, addAll, clear, contains, containsAll, isEmpty, iterator, remove, removeAll, retainAll, size, standardAddAll, standardClear, standardContains, standardContainsAll, standardIsEmpty, standardRemove, standardRemoveAll, standardRetainAll, standardToArray, standardToArray, standardToString, toArray, toArraytoStringclone, finalize, getClass, notify, notifyAll, wait, wait, waitadd, addAll, clear, contains, containsAll, isEmpty, iterator, remove, removeAll, replaceAll, retainAll, size, sort, spliterator, toArray, toArrayparallelStream, removeIf, streamprotected abstract List<E> delegate()
ForwardingObjectReturns the backing delegate instance that methods are forwarded to. Abstract subclasses generally override this method with an abstract method that has a more specific return type, such as ForwardingSet.delegate(). Concrete subclasses override this method to supply the instance being decorated.
delegate in class ForwardingCollection<E>public boolean addAll(int index,
Collection<? extends E> elements)
public int lastIndexOf(Object element)
lastIndexOf in interface List<E>public ListIterator<E> listIterator()
listIterator in interface List<E>public ListIterator<E> listIterator(int index)
listIterator in interface List<E>public int hashCode()
protected boolean standardAdd(E element)
A sensible default implementation of ForwardingCollection.add(Object), in terms of add(int, Object). If you override add(int, Object), you may wish to override ForwardingCollection.add(Object) to forward to this implementation.
protected boolean standardAddAll(int index,
Iterable<? extends E> elements)
A sensible default implementation of addAll(int, Collection), in terms of the add method of listIterator(int). If you override listIterator(int), you may wish to override addAll(int, Collection) to forward to this implementation.
protected int standardIndexOf(@Nullable Object element)
A sensible default implementation of indexOf(java.lang.Object), in terms of listIterator(). If you override listIterator(), you may wish to override indexOf(java.lang.Object) to forward to this implementation.
protected int standardLastIndexOf(@Nullable Object element)
A sensible default implementation of lastIndexOf(java.lang.Object), in terms of listIterator(int). If you override listIterator(int), you may wish to override lastIndexOf(java.lang.Object) to forward to this implementation.
protected Iterator<E> standardIterator()
A sensible default implementation of ForwardingCollection.iterator(), in terms of listIterator(). If you override listIterator(), you may wish to override ForwardingCollection.iterator() to forward to this implementation.
protected ListIterator<E> standardListIterator()
A sensible default implementation of listIterator(), in terms of listIterator(int). If you override listIterator(int), you may wish to override listIterator() to forward to this implementation.
@Beta protected ListIterator<E> standardListIterator(int start)
A sensible default implementation of listIterator(int), in terms of ForwardingCollection.size(), get(int), set(int, Object), add(int, Object), and remove(int). If you override any of these methods, you may wish to override listIterator(int) to forward to this implementation.
@Beta protected List<E> standardSubList(int fromIndex, int toIndex)
A sensible default implementation of subList(int, int). If you override any other methods, you may wish to override subList(int,
int) to forward to this implementation.
@Beta protected boolean standardEquals(@Nullable Object object)
A sensible definition of equals(Object) in terms of ForwardingCollection.size() and ForwardingCollection.iterator(). If you override either of those methods, you may wish to override equals(Object) to forward to this implementation.
@Beta protected int standardHashCode()
A sensible definition of hashCode() in terms of ForwardingCollection.iterator(). If you override ForwardingCollection.iterator(), you may wish to override hashCode() to forward to this implementation.