|
The Collection interface (not to be confused with the
Collections class -- see later) defines the top-level methods for all collection
objects (that is, all objects that implement the Collection
interface).
Collection
List
Set
SortedSet
Comparable (in java.lang package)
Comparator
Enumeration
Iterator
ListIterator
Map
SortedMap
It defines the following methods (this is the original source, minus many
comments):
package java.util;
public interface Collection
{
// Query Operations
int size();
boolean isEmpty();
boolean contains(Object o);
Iterator iterator();
Object[] toArray();
Object[] toArray(Object a[]);
// Modification Operations
boolean add(Object o);
boolean remove(Object o);
// Bulk Operations
boolean containsAll(Collection c);
boolean addAll(Collection c);
boolean removeAll(Collection c);
boolean retainAll(Collection c);
void clear();
// Comparison and hashing
boolean equals(Object o);
int hashCode();
}
|
Note that the Collection interface itself does not enforce any policy, such
as no duplicates or ordering. Such policies are enforced by sub-interfaces
of the Collection interface.
| 