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 */ 16 package android.annotation; 17 18 import java.lang.annotation.Retention; 19 import java.lang.annotation.Target; 20 21 import static java.lang.annotation.ElementType.FIELD; 22 import static java.lang.annotation.ElementType.METHOD; 23 import static java.lang.annotation.ElementType.PARAMETER; 24 import 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 * @paramDoc This value may be {@code null}. 39 * @returnDoc This value may be {@code null}. 40 * @hide 41 */ 42 @Retention(SOURCE) 43 @Target({METHOD, PARAMETER, FIELD}) 44 public @interface Nullable { 45 } 46
