Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
DCollection |
|
| 1.0;1 |
1 | package org.odmg; | |
2 | ||
3 | ||
4 | ||
5 | ||
6 | ||
7 | /** | |
8 | ||
9 | * The base interface for all ODMG collections. | |
10 | ||
11 | * The ODMG collections are based on JavaSoft�s collection interfaces. | |
12 | ||
13 | * All of the operations defined by the JavaSoft <code>Collection</code> | |
14 | ||
15 | * interface are supported by an ODMG implementation of <code>DCollection</code>; | |
16 | ||
17 | * the exception <code>UnsupportedOperationException</code> is not thrown when a | |
18 | ||
19 | * call is made to any of the <code>Collection</code> methods. | |
20 | ||
21 | * <p> | |
22 | ||
23 | * <code>DCollection</code> contains methods used to perform queries on the collection. | |
24 | ||
25 | * The OQL query predicate is given as a string with the syntax of the | |
26 | ||
27 | * <code>where</code> clause of OQL. The predefined OQL variable <code>this</code> | |
28 | ||
29 | * is used inside the predicate to denote the current element of the collection. | |
30 | ||
31 | * @author David Jordan (as Java Editor of the Object Data Management Group) | |
32 | ||
33 | * @version ODMG 3.0 | |
34 | ||
35 | */ | |
36 | ||
37 | // * @see com.sun.java.util.collections.UnsupportedOperationException | |
38 | ||
39 | ||
40 | ||
41 | public interface DCollection extends java.util.Collection | |
42 | ||
43 | { | |
44 | ||
45 | /** | |
46 | ||
47 | * Selects the single element of the collection for which the provided OQL query | |
48 | ||
49 | * predicate is true. | |
50 | ||
51 | * @param predicate An OQL boolean query predicate. | |
52 | ||
53 | * @return The element that evaluates to true for the predicate. If no element | |
54 | ||
55 | * evaluates to true, null is returned. | |
56 | ||
57 | * @exception QueryInvalidException The query predicate is invalid. | |
58 | ||
59 | */ | |
60 | ||
61 | public Object selectElement(String predicate) throws QueryInvalidException; | |
62 | ||
63 | ||
64 | ||
65 | /** | |
66 | ||
67 | * Access all of the elements of the collection that evaluate to true for the | |
68 | ||
69 | * provided query predicate. | |
70 | ||
71 | * @param predicate An OQL boolean query predicate. | |
72 | ||
73 | * @return An iterator used to iterate over the elements that evaluated true for the predicate. | |
74 | ||
75 | * @exception QueryInvalidException The query predicate is invalid. | |
76 | ||
77 | */ | |
78 | ||
79 | public java.util.Iterator select(String predicate) throws QueryInvalidException; | |
80 | ||
81 | ||
82 | ||
83 | /** | |
84 | ||
85 | * Evaluate the boolean query predicate for each element of the collection and | |
86 | ||
87 | * return a new collection that contains each element that evaluated to true. | |
88 | ||
89 | * @param predicate An OQL boolean query predicate. | |
90 | ||
91 | * @return A new collection containing the elements that evaluated true for the predicate. | |
92 | ||
93 | * @exception QueryInvalidException The query predicate is invalid. | |
94 | ||
95 | */ | |
96 | ||
97 | public DCollection query(String predicate) throws QueryInvalidException; | |
98 | ||
99 | ||
100 | ||
101 | /** | |
102 | ||
103 | * Determines whether there is an element of the collection that evaluates to true | |
104 | ||
105 | * for the predicate. | |
106 | ||
107 | * @param predicate An OQL boolean query predicate. | |
108 | ||
109 | * @return True if there is an element of the collection that evaluates to true | |
110 | ||
111 | * for the predicate, otherwise false. | |
112 | ||
113 | * @exception QueryInvalidException The query predicate is invalid. | |
114 | ||
115 | */ | |
116 | ||
117 | public boolean existsElement(String predicate) throws QueryInvalidException; | |
118 | ||
119 | } | |
120 |