Java in a Nutshell, 5th Edition [Electronic resources] نسخه متنی

This
abstract class is a partial implementation of
Collection that makes it easy to define custom
Collection implementations. To create an
unmodifiable collection, simply override size(
) and iterator( ). The
Iterator object returned by iterator(
) has to support only the hasNext( ) and
next( ) methods. To define a modifiable
collection, you must additionally override the add(
) method of
AbstractCollection and make sure the
Iterator returned by iterator(
) supports the remove(
) method. Some subclasses may choose
to override other methods to tune performance. In addition, it is
conventional that all subclasses provide two constructors: one that
takes no arguments and one that accepts a
Collection argument that specifies the initial
contents of the collection.

Note that if you subclass AbstractCollection
directly, you are implementing a

bag an
unordered collection that allows duplicate
elements. If your add( ) method rejects duplicate
elements, you should subclass AbstractSet instead.
See also AbstractList.

Figure 16-1. java.util.AbstractCollection<E>

public abstract class

AbstractCollection<E> implements Collection<E> {
// Protected Constructors
protected

AbstractCollection ( );
// Methods Implementing Collection
public boolean

add (E

o );
public boolean

addAll (Collection<? extends E>

c );
public void

clear ( );
public boolean

contains (Object

o );
public boolean

containsAll (Collection<?>

c );
public boolean

isEmpty ( );
public abstract Iterator<E>

iterator ( );
public boolean

remove (Object

o );
public boolean

removeAll (Collection<?>

c );
public boolean

retainAll (Collection<?>

c );
public abstract int

size ( );
public Object[ ]

toArray ( );
public <T> T[ ]

toArray (T[ ]

a );
// Public Methods Overriding Object
public String

toString ( );
}

Subclasses

AbstractList, AbstractQueue,
AbstractSet