1 /*
2 * Portions of this software was developed by employees of the National Institute
3 * of Standards and Technology (NIST), an agency of the Federal Government and is
4 * being made available as a public service. Pursuant to title 17 United States
5 * Code Section 105, works of NIST employees are not subject to copyright
6 * protection in the United States. This software may be subject to foreign
7 * copyright. Permission in the United States and in foreign countries, to the
8 * extent that NIST may hold copyright, to use, copy, modify, create derivative
9 * works, and distribute this software and its documentation without fee is hereby
10 * granted on a non-exclusive basis, provided that this notice and disclaimer
11 * of warranty appears in all copies.
12 *
13 * THE SOFTWARE IS PROVIDED 'AS IS' WITHOUT ANY WARRANTY OF ANY KIND, EITHER
14 * EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY
15 * THAT THE SOFTWARE WILL CONFORM TO SPECIFICATIONS, ANY IMPLIED WARRANTIES OF
16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND FREEDOM FROM
17 * INFRINGEMENT, AND ANY WARRANTY THAT THE DOCUMENTATION WILL CONFORM TO THE
18 * SOFTWARE, OR ANY WARRANTY THAT THE SOFTWARE WILL BE ERROR FREE. IN NO EVENT
19 * SHALL NIST BE LIABLE FOR ANY DAMAGES, INCLUDING, BUT NOT LIMITED TO, DIRECT,
20 * INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES, ARISING OUT OF, RESULTING FROM,
21 * OR IN ANY WAY CONNECTED WITH THIS SOFTWARE, WHETHER OR NOT BASED UPON WARRANTY,
22 * CONTRACT, TORT, OR OTHERWISE, WHETHER OR NOT INJURY WAS SUSTAINED BY PERSONS OR
23 * PROPERTY OR OTHERWISE, AND WHETHER OR NOT LOSS WAS SUSTAINED FROM, OR AROSE OUT
24 * OF THE RESULTS OF, OR USE OF, THE SOFTWARE OR SERVICES PROVIDED HEREUNDER.
25 */
26
27 package gov.nist.secauto.metaschema.databind.model.info;
28
29 import gov.nist.secauto.metaschema.core.util.ObjectUtils;
30
31 import java.util.Collection;
32
33 import edu.umd.cs.findbugs.annotations.Nullable;
34
35 class SingletonPropertyCollector implements IPropertyCollector {
36 private Object object;
37
38 @Override
39 public void add(Object item) {
40 if (object != null) {
41 throw new IllegalStateException("A value has already been set for this singleton");
42 }
43 object = item;
44 }
45
46 @Override
47 public void addAll(Collection<?> items) {
48 int size = items.size();
49 if (size > 1) {
50 throw new IllegalStateException("Multiple values cannot be set for this singleton");
51 } else if (size == 1) {
52 add(ObjectUtils.notNull(items.iterator().next()));
53 }
54 }
55
56 @Nullable
57 @Override
58 public Object getValue() {
59 return object;
60 }
61 }