Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
CriteriaUtils |
|
| 4.5;4.5 |
1 | package org.apache.ojb.broker.query; | |
2 | ||
3 | /* Copyright 2002-2005 The Apache Software Foundation | |
4 | * | |
5 | * Licensed under the Apache License, Version 2.0 (the "License"); | |
6 | * you may not use this file except in compliance with the License. | |
7 | * You may obtain a copy of the License at | |
8 | * | |
9 | * http://www.apache.org/licenses/LICENSE-2.0 | |
10 | * | |
11 | * Unless required by applicable law or agreed to in writing, software | |
12 | * distributed under the License is distributed on an "AS IS" BASIS, | |
13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
14 | * See the License for the specific language governing permissions and | |
15 | * limitations under the License. | |
16 | */ | |
17 | ||
18 | import java.util.*; | |
19 | ||
20 | /** | |
21 | * This Class contains utility functions for Criterias. | |
22 | * | |
23 | * @author <a href="mailto:on@ibis.odessa.ua">Oleg Nitz</a> | |
24 | * @version $Id: CriteriaUtils.java,v 1.1 2007-08-24 22:17:36 ewestfal Exp $ | |
25 | */ | |
26 | public class CriteriaUtils | |
27 | { | |
28 | ||
29 | /** | |
30 | * Disjunctive Normal Form: list of Criteria, which don't contain ORs, | |
31 | * the elements of the list joined by ORs give the condition equivalent | |
32 | * to the original Criteria. | |
33 | */ | |
34 | public static List getDNF(Criteria crit) | |
35 | { | |
36 | List dnf = new ArrayList(); | |
37 | Enumeration e = crit.getElements(); | |
38 | Criteria tmpCrit; | |
39 | ||
40 | while (e.hasMoreElements()) | |
41 | { | |
42 | Object o = e.nextElement(); | |
43 | if (o instanceof Criteria) | |
44 | { | |
45 | Criteria pc = (Criteria) o; | |
46 | switch (pc.getType()) | |
47 | { | |
48 | case (Criteria.OR): | |
49 | { | |
50 | dnf.addAll(getDNF(pc)); | |
51 | break; | |
52 | } | |
53 | case (Criteria.AND): | |
54 | { | |
55 | dnf = getDnfAndDnf(dnf, getDNF(pc)); | |
56 | break; | |
57 | } | |
58 | } | |
59 | } | |
60 | else | |
61 | { | |
62 | SelectionCriteria c = (SelectionCriteria) o; | |
63 | tmpCrit = new Criteria(); | |
64 | tmpCrit.getCriteria().add(c); | |
65 | if (dnf.isEmpty()) | |
66 | { | |
67 | dnf.add(tmpCrit); | |
68 | } | |
69 | else | |
70 | { | |
71 | //#ifdef JDK13 | |
72 | dnf = getDnfAndDnf(dnf, Collections.singletonList(tmpCrit)); | |
73 | //#else | |
74 | /* | |
75 | Vector singletonList = new Vector(1); | |
76 | singletonList.add(tmpCrit); | |
77 | dnf = getDnfAndDnf(dnf,singletonList); | |
78 | */ | |
79 | ||
80 | //#endif | |
81 | ||
82 | ||
83 | } | |
84 | } | |
85 | } // while | |
86 | ||
87 | return dnf; | |
88 | } | |
89 | ||
90 | /** | |
91 | * (a OR b) AND (c OR d) -> (a AND c) OR (a AND d) OR (b AND c) OR (b AND d) | |
92 | */ | |
93 | private static List getDnfAndDnf(List dnf1, List dnf2) | |
94 | { | |
95 | ArrayList dnf = new ArrayList(); | |
96 | ||
97 | for (Iterator it1 = dnf1.iterator(); it1.hasNext(); ) | |
98 | { | |
99 | Criteria crit1 = (Criteria) it1.next(); | |
100 | ||
101 | for (Iterator it2 = dnf2.iterator(); it2.hasNext(); ) | |
102 | { | |
103 | Criteria crit2 = (Criteria) it2.next(); | |
104 | Criteria crit = new Criteria(); | |
105 | crit.getCriteria().addAll(crit1.getCriteria()); | |
106 | crit.getCriteria().addAll(crit2.getCriteria()); | |
107 | dnf.add(crit); | |
108 | } | |
109 | } | |
110 | ||
111 | return dnf; | |
112 | } | |
113 | } | |
114 |