001    /**
002     *
003     * Licensed to the Apache Software Foundation (ASF) under one or more
004     * contributor license agreements.  See the NOTICE file distributed with
005     * this work for additional information regarding copyright ownership.
006     * The ASF licenses this file to You under the Apache License, Version 2.0
007     * (the "License"); you may not use this file except in compliance with
008     * the License.  You may obtain a copy of the License at
009     *
010     * http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    package org.apache.camel.spring.spi;
019    
020    import static org.apache.camel.util.ObjectHelper.notNull;
021    
022    import org.apache.camel.CamelContext;
023    import org.apache.camel.Component;
024    import org.apache.camel.spi.ComponentResolver;
025    import org.springframework.beans.factory.NoSuchBeanDefinitionException;
026    import org.springframework.context.ApplicationContext;
027    
028    /**
029     * An implementation of {@link ComponentResolver} which tries to find a Camel {@link Component}
030     * in the Spring {@link ApplicationContext} first; if its not there it defaults to the auto-discovery mechanism.
031     *
032     * @version $Revision: 530555 $
033     */
034    public class SpringComponentResolver implements ComponentResolver {
035        private final ApplicationContext applicationContext;
036        private final ComponentResolver nextResolver;
037    
038        public SpringComponentResolver(ApplicationContext applicationContext, ComponentResolver nextResolver) {
039            notNull(applicationContext, "applicationContext");
040            this.applicationContext = applicationContext;
041            this.nextResolver = nextResolver;
042        }
043    
044        public Component resolveComponent(String name, CamelContext context) throws Exception {
045            Object bean = null;
046            try {
047                bean = applicationContext.getBean(name);
048            }
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                }
056                else {
057                    throw new IllegalArgumentException("Bean with name: " + name + " in spring context is not a Component: " + bean);
058                }
059            }
060            if (nextResolver == null) {
061                return null;
062            }
063            return nextResolver.resolveComponent(name, context);
064        }
065    }