001/* 002 * Copyright 2002-2019 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.lang; 018 019import java.lang.annotation.Documented; 020import java.lang.annotation.ElementType; 021import java.lang.annotation.Retention; 022import java.lang.annotation.RetentionPolicy; 023import java.lang.annotation.Target; 024 025import javax.annotation.Nonnull; 026import javax.annotation.meta.TypeQualifierNickname; 027 028/** 029 * A common Spring annotation to declare that annotated elements cannot be {@code null}. 030 * 031 * <p>Leverages JSR-305 meta-annotations to indicate nullability in Java to common 032 * tools with JSR-305 support and used by Kotlin to infer nullability of Spring API. 033 * 034 * <p>Should be used at parameter, return value, and field level. Method overrides should 035 * repeat parent {@code @NonNull} annotations unless they behave differently. 036 * 037 * <p>Use {@code @NonNullApi} (scope = parameters + return values) and/or {@code @NonNullFields} 038 * (scope = fields) to set the default behavior to non-nullable in order to avoid annotating 039 * your whole codebase with {@code @NonNull}. 040 * 041 * @author Sebastien Deleuze 042 * @author Juergen Hoeller 043 * @since 5.0 044 * @see NonNullApi 045 * @see NonNullFields 046 * @see Nullable 047 */ 048@Target({ElementType.METHOD, ElementType.PARAMETER, ElementType.FIELD}) 049@Retention(RetentionPolicy.RUNTIME) 050@Documented 051@Nonnull 052@TypeQualifierNickname 053public @interface NonNull { 054}