The collections api - Data Structures and Problem Solving Using Java - page 239

1 package weiss.util;
2
3 /**
4 * Collection interface; the root of all 1.5 collections.
5 */
6 public interface Collection<AnyType> extends Iterable<AnyType>, java.io.Serializable
7 {
8 /**
9 * Returns the number of items in this collection.
10 */
11 int size( );
12
13 /**
14 * Tests if this collection is empty.
15 */
16 boolean isEmpty( );
17
18 /**
19 * Tests if some item is in this collection.
20 */
21 boolean contains( Object x );
22
23 /**
24 * Adds an item to this collection.
25 */
26 boolean add( AnyType x );
27
28 /**
29 * Removes an item from this collection.
30 */
31 boolean remove( Object x );
32
33 /**
34 * Change the size of this collection to zero.
35 */
36 void clear( );
37
38 /**
39 * Obtains an Iterator object used to traverse the collection.
40 */
41 Iterator<AnyType> iterator( );
42
43 /**
44 * Obtains a primitive array view of the collection.
45 */
46 Object [ ] toArray( );
47
48 /**
49 * Obtains a primitive array view of the collection.
50 */
51 <OtherType> OtherType [ ] toArray( OtherType [ ] arr );
52 }
figure 6.9
A sample specification of the Collection interface