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;
019    
020    import static org.apache.camel.util.ObjectHelper.notNull;
021    
022    import java.net.URI;
023    
024    import org.apache.camel.CamelContext;
025    import org.apache.camel.Component;
026    import org.apache.camel.spi.ComponentResolver;
027    import org.springframework.context.ApplicationContext;
028    
029    /**
030     * An implementation of {@link ComponentResolver} which tries to find a Camel {@link Component}
031     * in the Spring {@link ApplicationContext} first; if its not there it defaults to the auto-discovery mechanism.
032     *
033     * @version $Revision: 525634 $
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 uri, CamelContext context) throws Exception {
046            String scheme = new URI(uri).getScheme();
047            Object bean = applicationContext.getBean(scheme);
048            if (bean != null) {
049                if (bean instanceof Component) {
050                    return (Component) bean;
051                }
052                else {
053                    throw new IllegalArgumentException("Bean with name: " + bean + " in spring context is not a Component: " + bean);
054                }
055            }
056            if (nextResolver == null) {
057                return null;
058            }
059            return nextResolver.resolveComponent(uri, context);
060        }
061    }