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.beans.factory.config; 018 019import java.io.Serializable; 020 021import org.springframework.lang.Nullable; 022 023/** 024 * Simple marker class for an individually autowired property value, to be added 025 * to {@link BeanDefinition#getPropertyValues()} for a specific bean property. 026 * 027 * <p>At runtime, this will be replaced with a {@link DependencyDescriptor} 028 * for the corresponding bean property's write method, eventually to be resolved 029 * through a {@link AutowireCapableBeanFactory#resolveDependency} step. 030 * 031 * @author Juergen Hoeller 032 * @since 5.2 033 * @see AutowireCapableBeanFactory#resolveDependency 034 * @see BeanDefinition#getPropertyValues() 035 * @see org.springframework.beans.factory.support.BeanDefinitionBuilder#addAutowiredProperty 036 */ 037@SuppressWarnings("serial") 038public final class AutowiredPropertyMarker implements Serializable { 039 040 /** 041 * The canonical instance for the autowired marker value. 042 */ 043 public static final Object INSTANCE = new AutowiredPropertyMarker(); 044 045 046 private AutowiredPropertyMarker() { 047 } 048 049 private Object readResolve() { 050 return INSTANCE; 051 } 052 053 054 @Override 055 public boolean equals(@Nullable Object obj) { 056 return (this == obj); 057 } 058 059 @Override 060 public int hashCode() { 061 return AutowiredPropertyMarker.class.hashCode(); 062 } 063 064 @Override 065 public String toString() { 066 return "(autowired)"; 067 } 068 069}