01: /*
02: * (c) Copyright 2007 by Volker Bergmann. All rights reserved.
03: *
04: * Redistribution and use in source and binary forms, with or without
05: * modification, is permitted under the terms of the
06: * GNU General Public License.
07: *
08: * For redistributing this software or a derivative work under a license other
09: * than the GPL-compatible Free Software License as defined by the Free
10: * Software Foundation or approved by OSI, you must first obtain a commercial
11: * license to this software product from Volker Bergmann.
12: *
13: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
14: * WITHOUT A WARRANTY OF ANY KIND. ALL EXPRESS OR IMPLIED CONDITIONS,
15: * REPRESENTATIONS AND WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF
16: * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE
17: * HEREBY EXCLUDED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
18: * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
19: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
20: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
21: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
22: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
23: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
24: * POSSIBILITY OF SUCH DAMAGE.
25: */
26:
27: package org.databene.benerator.wrapper;
28:
29: import org.databene.benerator.*;
30:
31: /**
32: * Forwards the output of other generators in random order, but at most once.<br/>
33: * <br/>
34: * Created: 17.11.2007 17:12:07
35: */
36: public class UniqueAlternativeGenerator<E> extends
37: MultiGeneratorWrapper<E, E> {
38:
39: private Class<E> targetType;
40:
41: // constructors ----------------------------------------------------------------------------------------------------
42:
43: public UniqueAlternativeGenerator() {
44: this (null);
45: }
46:
47: /** Initializes the generator to a collection of source generators */
48: public UniqueAlternativeGenerator(Class<E> targetType,
49: Generator<E>... sources) {
50: super (sources);
51: this .targetType = targetType;
52: }
53:
54: // Generator implementation ----------------------------------------------------------------------------------------
55:
56: public Class<E> getGeneratedType() {
57: return targetType;
58: }
59:
60: public boolean available() {
61: for (Generator<E> source : sources)
62: if (source.available())
63: return true;
64: return false;
65: }
66:
67: /** @see org.databene.benerator.Generator#generate() */
68: public E generate() {
69: if (!available())
70: throw new IllegalGeneratorStateException(
71: "Generator is not available: " + this );
72: int index;
73: do {
74: index = SimpleRandom.randomInt(0, sources.length - 1);
75: } while (!sources[index].available());
76: return sources[index].generate();
77: }
78:
79: }
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