KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > com > db4o > test > SelectDistinct


1 /* Copyright (C) 2004 - 2006 db4objects Inc. http://www.db4o.com
2
3 This file is part of the db4o open source object database.
4
5 db4o is free software; you can redistribute it and/or modify it under
6 the terms of version 2 of the GNU General Public License as published
7 by the Free Software Foundation and as clarified by db4objects' GPL
8 interpretation policy, available at
9 http://www.db4o.com/about/company/legalpolicies/gplinterpretation/
10 Alternatively you can write to db4objects, Inc., 1900 S Norfolk Street,
11 Suite 350, San Mateo, CA 94403, USA.
12
13 db4o is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
17
18 You should have received a copy of the GNU General Public License along
19 with this program; if not, write to the Free Software Foundation, Inc.,
20 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
21 package com.db4o.test;
22
23 import java.util.*;
24
25 import com.db4o.*;
26 import com.db4o.query.*;
27
28 public class SelectDistinct {
29
30     public String JavaDoc name;
31
32     public SelectDistinct() {
33     }
34
35     public SelectDistinct(String JavaDoc name) {
36         this.name = name;
37     }
38
39     public void store() {
40         Test.store(new SelectDistinct("a"));
41         Test.store(new SelectDistinct("a"));
42         Test.store(new SelectDistinct("a"));
43         Test.store(new SelectDistinct("b"));
44         Test.store(new SelectDistinct("b"));
45         Test.store(new SelectDistinct("c"));
46         Test.store(new SelectDistinct("c"));
47         Test.store(new SelectDistinct("d"));
48         Test.store(new SelectDistinct("e"));
49     }
50
51     public void test() {
52
53         String JavaDoc[] expected = new String JavaDoc[] { "a", "b", "c", "d", "e"};
54
55         Query q = Test.query();
56         q.constrain(SelectDistinct.class);
57         q.constrain(new Evaluation() {
58
59             private Hashtable ht = new Hashtable();
60
61             public void evaluate(Candidate candidate) {
62                 SelectDistinct sd = (SelectDistinct) candidate.getObject();
63                 boolean isDistinct = ht.get(sd.name) == null;
64                 candidate.include(isDistinct);
65                 if (isDistinct) {
66                     ht.put(sd.name, new Object JavaDoc());
67                 }
68
69             }
70         });
71
72         ObjectSet objectSet = q.execute();
73         while (objectSet.hasNext()) {
74             SelectDistinct sd = (SelectDistinct) objectSet.next();
75             boolean found = false;
76             for (int i = 0; i < expected.length; i++) {
77                 if (sd.name.equals(expected[i])) {
78                     expected[i] = null;
79                     found = true;
80                     break;
81                 }
82             }
83             Test.ensure(found);
84         }
85
86         for (int i = 0; i < expected.length; i++) {
87             Test.ensure(expected[i] == null);
88         }
89     }
90 }
Popular Tags