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.RoutesBuilder;
025    import org.apache.camel.spi.PackageScanClassResolver;
026    import org.apache.commons.logging.Log;
027    import org.apache.commons.logging.LogFactory;
028    import org.springframework.beans.factory.config.BeanPostProcessor;
029    import org.springframework.context.ApplicationContext;
030    
031    /**
032     * A helper class which will find all {@link org.apache.camel.builder.RouteBuilder} instances on the classpath
033     *
034     * @version $Revision: 954861 $
035     */
036    public class PackageScanRouteBuilderFinder {
037        private static final transient Log LOG = LogFactory.getLog(PackageScanRouteBuilderFinder.class);
038        private final SpringCamelContext camelContext;
039        private final String[] packages;
040        private final PackageScanClassResolver resolver;
041        private final ApplicationContext applicationContext;
042        private final BeanPostProcessor beanPostProcessor;
043    
044        public PackageScanRouteBuilderFinder(SpringCamelContext camelContext, String[] packages, ClassLoader classLoader,
045                                             BeanPostProcessor postProcessor, PackageScanClassResolver resolver) {
046            this.camelContext = camelContext;
047            this.applicationContext = camelContext.getApplicationContext();
048            this.packages = packages;
049            this.beanPostProcessor = postProcessor;
050            this.resolver = resolver;
051            // add our provided loader as well
052            resolver.addClassLoader(classLoader);
053        }
054    
055        /**
056         * Appends all the {@link org.apache.camel.builder.RouteBuilder} instances that can be found on the classpath
057         */
058        public void appendBuilders(List<RoutesBuilder> list) throws IllegalAccessException, InstantiationException {
059            Set<Class<?>> classes = resolver.findImplementations(RoutesBuilder.class, packages);
060            for (Class aClass : classes) {
061                if (LOG.isTraceEnabled()) {
062                    LOG.trace("Found RouteBuilder class: " + aClass);
063                }
064    
065                // certain beans should be ignored
066                if (shouldIgnoreBean(aClass)) {
067                    if (LOG.isDebugEnabled()) {
068                        LOG.debug("Ignoring RouteBuilder class: " + aClass);
069                    }
070                    continue;
071                }
072    
073                if (!isValidClass(aClass)) {
074                    if (LOG.isDebugEnabled()) {
075                        LOG.debug("Ignoring invalid RouteBuilder class: " + aClass);
076                    }
077                    continue;
078                }
079    
080                // type is valid so create and instantiate the builder
081                RoutesBuilder builder = instantiateBuilder(aClass);
082                if (beanPostProcessor != null) {
083                    // Inject the annotated resource
084                    beanPostProcessor.postProcessBeforeInitialization(builder, builder.toString());
085                }
086                if (LOG.isDebugEnabled()) {
087                    LOG.debug("Adding instantiated RouteBuilder: " + builder);
088                }
089                list.add(builder);
090            }
091        }
092    
093        /**
094         * Lets ignore beans that are explicitly configured in the Spring XML files
095         */
096        protected boolean shouldIgnoreBean(Class<?> type) {
097            Map beans = applicationContext.getBeansOfType(type, true, true);
098            if (beans == null || beans.isEmpty()) {
099                return false;
100            }
101            return true;
102        }
103    
104        /**
105         * Returns true if the object is non-abstract and supports a zero argument constructor
106         */
107        protected boolean isValidClass(Class type) {
108            if (!Modifier.isAbstract(type.getModifiers()) && !type.isInterface()) {
109                return true;
110            }
111            return false;
112        }
113    
114        @SuppressWarnings("unchecked")
115        protected RoutesBuilder instantiateBuilder(Class type) throws IllegalAccessException, InstantiationException {
116            return (RoutesBuilder) camelContext.getInjector().newInstance(type);
117        }
118    }