001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.camel.spring.spi;
018    
019    import org.apache.camel.CamelContext;
020    import org.apache.camel.Component;
021    import org.apache.camel.spi.ComponentResolver;
022    
023    import org.springframework.beans.factory.NoSuchBeanDefinitionException;
024    import org.springframework.context.ApplicationContext;
025    
026    import static org.apache.camel.util.ObjectHelper.notNull;
027    
028    /**
029     * An implementation of {@link ComponentResolver} which tries to find a Camel
030     * {@link Component} in the Spring {@link ApplicationContext} first; if its not
031     * there it defaults to the auto-discovery mechanism.
032     * 
033     * @version $Revision: 563665 $
034     */
035    public class SpringComponentResolver implements ComponentResolver {
036        private final ApplicationContext applicationContext;
037        private final ComponentResolver nextResolver;
038    
039        public SpringComponentResolver(ApplicationContext applicationContext, ComponentResolver nextResolver) {
040            notNull(applicationContext, "applicationContext");
041            this.applicationContext = applicationContext;
042            this.nextResolver = nextResolver;
043        }
044    
045        public Component resolveComponent(String name, CamelContext context) throws Exception {
046            Object bean = null;
047            try {
048                bean = applicationContext.getBean(name);
049            } catch (NoSuchBeanDefinitionException e) {
050                // ignore its not an error
051            }
052            if (bean != null) {
053                if (bean instanceof Component) {
054                    return (Component)bean;
055                } else {
056                    throw new IllegalArgumentException("Bean with name: " + name + " in spring context is not a Component: " + bean);
057                }
058            }
059            if (nextResolver == null) {
060                return null;
061            }
062            return nextResolver.resolveComponent(name, context);
063        }
064    }