001/*
002 * Copyright 2002-2017 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.support;
018
019import java.lang.reflect.Method;
020import java.lang.reflect.Modifier;
021
022import org.springframework.lang.Nullable;
023import org.springframework.util.ObjectUtils;
024
025/**
026 * Represents an override of a method that looks up an object in the same IoC context.
027 *
028 * <p>Methods eligible for lookup override must not have arguments.
029 *
030 * @author Rod Johnson
031 * @author Juergen Hoeller
032 * @since 1.1
033 */
034public class LookupOverride extends MethodOverride {
035
036        @Nullable
037        private final String beanName;
038
039        @Nullable
040        private Method method;
041
042
043        /**
044         * Construct a new LookupOverride.
045         * @param methodName the name of the method to override
046         * @param beanName the name of the bean in the current {@code BeanFactory}
047         * that the overridden method should return (may be {@code null})
048         */
049        public LookupOverride(String methodName, @Nullable String beanName) {
050                super(methodName);
051                this.beanName = beanName;
052        }
053
054        /**
055         * Construct a new LookupOverride.
056         * @param method the method to override
057         * @param beanName the name of the bean in the current {@code BeanFactory}
058         * that the overridden method should return (may be {@code null})
059         */
060        public LookupOverride(Method method, @Nullable String beanName) {
061                super(method.getName());
062                this.method = method;
063                this.beanName = beanName;
064        }
065
066
067        /**
068         * Return the name of the bean that should be returned by this method.
069         */
070        @Nullable
071        public String getBeanName() {
072                return this.beanName;
073        }
074
075        /**
076         * Match the specified method by {@link Method} reference or method name.
077         * <p>For backwards compatibility reasons, in a scenario with overloaded
078         * non-abstract methods of the given name, only the no-arg variant of a
079         * method will be turned into a container-driven lookup method.
080         * <p>In case of a provided {@link Method}, only straight matches will
081         * be considered, usually demarcated by the {@code @Lookup} annotation.
082         */
083        @Override
084        public boolean matches(Method method) {
085                if (this.method != null) {
086                        return method.equals(this.method);
087                }
088                else {
089                        return (method.getName().equals(getMethodName()) && (!isOverloaded() ||
090                                        Modifier.isAbstract(method.getModifiers()) || method.getParameterCount() == 0));
091                }
092        }
093
094
095        @Override
096        public boolean equals(@Nullable Object other) {
097                if (!(other instanceof LookupOverride) || !super.equals(other)) {
098                        return false;
099                }
100                LookupOverride that = (LookupOverride) other;
101                return (ObjectUtils.nullSafeEquals(this.method, that.method) &&
102                                ObjectUtils.nullSafeEquals(this.beanName, that.beanName));
103        }
104
105        @Override
106        public int hashCode() {
107                return (29 * super.hashCode() + ObjectUtils.nullSafeHashCode(this.beanName));
108        }
109
110        @Override
111        public String toString() {
112                return "LookupOverride for method '" + getMethodName() + "'";
113        }
114
115}