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 org.apache.camel.builder.RouteBuilder;
021    import org.apache.camel.util.ResolverUtil;
022    import org.springframework.beans.BeansException;
023    import org.springframework.context.ApplicationContext;
024    import org.springframework.context.ApplicationContextAware;
025    
026    import java.lang.reflect.Constructor;
027    import java.lang.reflect.Modifier;
028    import java.util.List;
029    import java.util.Map;
030    import java.util.Set;
031    
032    /**
033     * A helper class which will find all {@link RouteBuilder} instances on the classpath
034     *
035     * @version $Revision: 521369 $
036     */
037    public class RouteBuilderFinder implements ApplicationContextAware {
038        private String[] packages = {};
039        private ApplicationContext applicationContext;
040        private ResolverUtil resolver = new ResolverUtil();
041    
042        public RouteBuilderFinder(ApplicationContext applicationContext, String[] packages) {
043            this.applicationContext = applicationContext;
044            this.packages = packages;
045        }
046    
047        public RouteBuilderFinder(CamelContextFactoryBean factoryBean) {
048            this.applicationContext = factoryBean.getApplicationContext();
049            this.packages = factoryBean.getPackages();
050        }
051    
052        public String[] getPackages() {
053            return packages;
054        }
055    
056        public void setPackages(String[] packages) {
057            this.packages = packages;
058        }
059    
060        public ApplicationContext getApplicationContext() {
061            return applicationContext;
062        }
063    
064        public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
065            this.applicationContext = applicationContext;
066        }
067    
068        /**
069         * Appends all the {@link RouteBuilder} instances that can be found on the classpath
070         */
071        public void appendBuilders(List<RouteBuilder> list) throws IllegalAccessException, InstantiationException {
072            resolver.findImplementations(RouteBuilder.class, packages);
073            //resolver.findAnnotated(Endpoint.class, packages);
074            Set<Class> classes = resolver.getClasses();
075            for (Class aClass : classes) {
076                if (shouldIgnoreBean(aClass)) {
077                    continue;
078                }
079                if (isValidClass(aClass)) {
080                    list.add(instantiateBuilder(aClass));
081                }
082            }
083        }
084    
085        public void destroy() throws Exception {
086        }
087    
088        /**
089         * Lets ignore beans that are not explicitly configured in the spring.xml
090         */
091        protected boolean shouldIgnoreBean(Class type) {
092            Map beans = applicationContext.getBeansOfType(type, true, true);
093            if (beans == null || beans.isEmpty()) {
094                return false;
095            }
096            // TODO apply some filter?
097            return true;
098        }
099    
100        /**
101         * Returns true if the object is non-abstract and supports a zero argument constructor
102         */
103        protected boolean isValidClass(Class type) {
104            if (!Modifier.isAbstract(type.getModifiers()) && !type.isInterface()) {
105                Constructor[] constructors = type.getDeclaredConstructors();
106                for (Constructor constructor : constructors) {
107                    Class[] classes = constructor.getParameterTypes();
108                    if (classes.length == 0) {
109                        return true;
110                    }
111                }
112            }
113            return false;
114        }
115    
116        protected RouteBuilder instantiateBuilder(Class type) throws IllegalAccessException, InstantiationException {
117            // TODO we could support spring-injection for these types
118            return (RouteBuilder) type.newInstance();
119        }
120    }