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;
018    
019    import java.lang.reflect.Modifier;
020    import java.util.List;
021    import java.util.Map;
022    import java.util.Set;
023    
024    import org.apache.camel.Routes;
025    import org.apache.camel.builder.RouteBuilder;
026    import org.apache.camel.util.ResolverUtil;
027    import org.apache.commons.logging.Log;
028    import org.apache.commons.logging.LogFactory;
029    import org.springframework.beans.factory.config.BeanPostProcessor;
030    import org.springframework.context.ApplicationContext;
031    
032    /**
033     * A helper class which will find all {@link RouteBuilder} instances on the classpath
034     *
035     * @version $Revision: 54161 $
036     */
037    public class RouteBuilderFinder {
038        private static final transient Log LOG = LogFactory.getLog(RouteBuilderFinder.class);
039        private final SpringCamelContext camelContext;
040        private final String[] packages;
041        private ApplicationContext applicationContext;
042        private ResolverUtil resolver = new ResolverUtil();
043        private BeanPostProcessor beanPostProcessor;
044    
045        public RouteBuilderFinder(SpringCamelContext camelContext, String[] packages, ClassLoader classLoader, BeanPostProcessor postProcessor) {
046            this.camelContext = camelContext;
047            this.applicationContext = camelContext.getApplicationContext();
048            this.packages = packages;
049            this.beanPostProcessor = postProcessor;
050    
051            // lets add all the available class loaders just in case of weirdness
052            // we could make this more strict once we've worked out all the gremlins
053            // in servicemix-camel
054            Set set = resolver.getClassLoaders();
055            set.clear();
056            set.add(classLoader);
057    /*
058            set.add(classLoader);
059            set.add(applicationContext.getClassLoader());
060            set.add(getClass().getClassLoader());
061    */
062        }
063    
064    
065        public String[] getPackages() {
066            return packages;
067        }
068    
069        public ApplicationContext getApplicationContext() {
070            return applicationContext;
071        }
072    
073    
074        /**
075         * Appends all the {@link RouteBuilder} instances that can be found on the classpath
076         */
077        public void appendBuilders(List<Routes> list) throws IllegalAccessException, InstantiationException {
078            resolver.findImplementations(Routes.class, packages);
079            Set<Class> classes = resolver.getClasses();
080            for (Class aClass : classes) {
081                if (shouldIgnoreBean(aClass)) {
082                    continue;
083                }
084                if (isValidClass(aClass)) {
085                    Routes builder = instantiateBuilder(aClass);
086                    if (beanPostProcessor != null) {
087                        // Inject the annotated resource
088                        beanPostProcessor.postProcessBeforeInitialization(builder, builder.toString());
089                    }
090                    list.add(builder);
091                }
092            }
093        }
094    
095        public void destroy() throws Exception {
096        }
097    
098        /**
099         * Lets ignore beans that are not explicitly configured in the spring.xml
100         */
101        protected boolean shouldIgnoreBean(Class type) {
102            Map beans = applicationContext.getBeansOfType(type, true, true);
103            if (beans == null || beans.isEmpty()) {
104                return false;
105            }
106            // TODO apply some filter?
107            return true;
108        }
109    
110        /**
111         * Returns true if the object is non-abstract and supports a zero argument constructor
112         */
113        protected boolean isValidClass(Class type) {
114            if (!Modifier.isAbstract(type.getModifiers()) && !type.isInterface()) {
115                return true;
116            }
117            return false;
118        }
119    
120        protected Routes instantiateBuilder(Class type) throws IllegalAccessException, InstantiationException {
121            return (Routes) camelContext.getInjector().newInstance(type);
122        }
123    }