MapFeature.java revision 0888a09821a98ac0680fad765217302858e70fa4 
1/*
2 * Copyright (C) 2008 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.google.common.collect.testing.features;
18
19import com.google.common.annotations.GwtCompatible;
20import com.google.common.collect.testing.Helpers;
21
22import java.lang.annotation.Inherited;
23import java.lang.annotation.Retention;
24import java.lang.annotation.RetentionPolicy;
25import java.util.Map;
26import java.util.Set;
27
28/**
29 * Optional features of classes derived from {@code Map}.
30 *
31 * @author George van den Driessche
32 */
33// Enum values use constructors with generic varargs.
34@SuppressWarnings("unchecked")
35@GwtCompatible
36public enum MapFeature implements Feature<Map> {
37  /**
38   * The map does not throw {@code NullPointerException} on calls such as
39   * {@code containsKey(null)}, {@code get(null)},
40   * {@code keySet().contains(null)} or {@code remove(null)}.
41   */
42  ALLOWS_NULL_KEY_QUERIES,
43  ALLOWS_NULL_KEYS(ALLOWS_NULL_KEY_QUERIES),
44  /**
45   * The map does not throw {@code NullPointerException} on calls such as
46   * {@code containsValue(null)}, {@code values().contains(null)} or
47   * {@code values().remove(null)}.
48   */
49  ALLOWS_NULL_VALUE_QUERIES,
50  ALLOWS_NULL_VALUES(ALLOWS_NULL_VALUE_QUERIES),
51  /**
52   * The map does not throw {@code NullPointerException} on calls such as
53   * {@code entrySet().contains(null)} or {@code entrySet().remove(null)}
54   */
55  ALLOWS_NULL_ENTRY_QUERIES,
56  /**
57   * The map does not throw {@code NullPointerException} on any {@code null}
58   * queries.
59   *
60   * @see #ALLOWS_NULL_KEY_QUERIES
61   * @see #ALLOWS_NULL_VALUE_QUERIES
62   * @see #ALLOWS_NULL_ENTRY_QUERIES
63   */
64  ALLOWS_ANY_NULL_QUERIES(
65      ALLOWS_NULL_ENTRY_QUERIES,
66      ALLOWS_NULL_KEY_QUERIES,
67      ALLOWS_NULL_VALUE_QUERIES
68  ),
69  RESTRICTS_KEYS,
70  RESTRICTS_VALUES,
71  SUPPORTS_PUT,
72  SUPPORTS_REMOVE,
73  FAILS_FAST_ON_CONCURRENT_MODIFICATION,
74  /**
75   * Indicates that the constructor or factory method of a map, usually an
76   * immutable map, throws an {@link IllegalArgumentException} when presented
77   * with duplicate keys instead of discarding all but one.
78   */
79  REJECTS_DUPLICATES_AT_CREATION,
80
81  GENERAL_PURPOSE(
82      SUPPORTS_PUT,
83      SUPPORTS_REMOVE
84  );
85
86  private final Set<Feature<? super Map>> implied;
87
88  MapFeature(Feature<? super Map> ... implied) {
89    this.implied = Helpers.copyToSet(implied);
90  }
91
92  @Override
93  public Set<Feature<? super Map>> getImpliedFeatures() {
94    return implied;
95  }
96
97  @Retention(RetentionPolicy.RUNTIME)
98  @Inherited
99  @TesterAnnotation
100  public @interface Require {
101    public abstract MapFeature[] value() default {};
102    public abstract MapFeature[] absent() default {};
103  }
104}
105