1/*
2 * Copyright (C) 2013 The Android Open Source Project
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 */
16package android.annotation;
17
18import java.lang.annotation.Retention;
19import java.lang.annotation.Target;
20
21import static java.lang.annotation.ElementType.FIELD;
22import static java.lang.annotation.ElementType.METHOD;
23import static java.lang.annotation.ElementType.PARAMETER;
24import static java.lang.annotation.RetentionPolicy.SOURCE;
25
26/**
27 * Denotes that a parameter, field or method return value can be null.
28 * <p>
29 * When decorating a method call parameter, this denotes that the parameter can
30 * legitimately be null and the method will gracefully deal with it. Typically
31 * used on optional parameters.
32 * <p>
33 * When decorating a method, this denotes the method might legitimately return
34 * null.
35 * <p>
36 * This is a marker annotation and it has no specific attributes.
37 *
38 * @hide
39 */
40@Retention(SOURCE)
41@Target({METHOD, PARAMETER, FIELD})
42public @interface Nullable {
43}
44