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.aop.config;
018
019import java.lang.reflect.Method;
020
021import org.springframework.beans.BeanUtils;
022import org.springframework.beans.factory.BeanFactory;
023import org.springframework.beans.factory.BeanFactoryAware;
024import org.springframework.beans.factory.FactoryBean;
025import org.springframework.lang.Nullable;
026import org.springframework.util.StringUtils;
027
028/**
029 * {@link FactoryBean} implementation that locates a {@link Method} on a specified bean.
030 *
031 * @author Rob Harrop
032 * @since 2.0
033 */
034public class MethodLocatingFactoryBean implements FactoryBean<Method>, BeanFactoryAware {
035
036        @Nullable
037        private String targetBeanName;
038
039        @Nullable
040        private String methodName;
041
042        @Nullable
043        private Method method;
044
045
046        /**
047         * Set the name of the bean to locate the {@link Method} on.
048         * <p>This property is required.
049         * @param targetBeanName the name of the bean to locate the {@link Method} on
050         */
051        public void setTargetBeanName(String targetBeanName) {
052                this.targetBeanName = targetBeanName;
053        }
054
055        /**
056         * Set the name of the {@link Method} to locate.
057         * <p>This property is required.
058         * @param methodName the name of the {@link Method} to locate
059         */
060        public void setMethodName(String methodName) {
061                this.methodName = methodName;
062        }
063
064        @Override
065        public void setBeanFactory(BeanFactory beanFactory) {
066                if (!StringUtils.hasText(this.targetBeanName)) {
067                        throw new IllegalArgumentException("Property 'targetBeanName' is required");
068                }
069                if (!StringUtils.hasText(this.methodName)) {
070                        throw new IllegalArgumentException("Property 'methodName' is required");
071                }
072
073                Class<?> beanClass = beanFactory.getType(this.targetBeanName);
074                if (beanClass == null) {
075                        throw new IllegalArgumentException("Can't determine type of bean with name '" + this.targetBeanName + "'");
076                }
077                this.method = BeanUtils.resolveSignature(this.methodName, beanClass);
078
079                if (this.method == null) {
080                        throw new IllegalArgumentException("Unable to locate method [" + this.methodName +
081                                        "] on bean [" + this.targetBeanName + "]");
082                }
083        }
084
085
086        @Override
087        @Nullable
088        public Method getObject() throws Exception {
089                return this.method;
090        }
091
092        @Override
093        public Class<Method> getObjectType() {
094                return Method.class;
095        }
096
097        @Override
098        public boolean isSingleton() {
099                return true;
100        }
101
102}