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 */
017package org.apache.camel.spring;
018
019import java.lang.reflect.Modifier;
020import java.util.List;
021import java.util.Map;
022import java.util.Set;
023
024import org.apache.camel.RoutesBuilder;
025import org.apache.camel.spi.PackageScanClassResolver;
026import org.slf4j.Logger;
027import org.slf4j.LoggerFactory;
028import org.springframework.beans.factory.config.BeanPostProcessor;
029import 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 
035 */
036public class PackageScanRouteBuilderFinder {
037    private static final Logger LOG = LoggerFactory.getLogger(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            LOG.trace("Found RouteBuilder class: {}", aClass);
062
063            // certain beans should be ignored
064            if (shouldIgnoreBean(aClass)) {
065                LOG.debug("Ignoring RouteBuilder class: {}", aClass);
066                continue;
067            }
068
069            if (!isValidClass(aClass)) {
070                LOG.debug("Ignoring invalid RouteBuilder class: {}", aClass);
071                continue;
072            }
073
074            // type is valid so create and instantiate the builder
075            @SuppressWarnings("unchecked")
076            RoutesBuilder builder = instantiateBuilder((Class<? extends RoutesBuilder>) aClass);
077            if (beanPostProcessor != null) {
078                // Inject the annotated resource
079                beanPostProcessor.postProcessBeforeInitialization(builder, builder.toString());
080            }
081            LOG.debug("Adding instantiated RouteBuilder: {}", builder);
082            list.add(builder);
083        }
084    }
085
086    /**
087     * Lets ignore beans that are explicitly configured in the Spring XML files
088     */
089    protected boolean shouldIgnoreBean(Class<?> type) {
090        Map<String, ?> beans = applicationContext.getBeansOfType(type, true, true);
091        if (beans == null || beans.isEmpty()) {
092            return false;
093        }
094        return true;
095    }
096
097    /**
098     * Returns <tt>true</tt>if the class is a public, non-abstract class
099     */
100    protected boolean isValidClass(Class<?> type) {
101        // should skip non public classes
102        if (!Modifier.isPublic(type.getModifiers())) {
103            return false;
104        }
105
106        if (!Modifier.isAbstract(type.getModifiers()) && !type.isInterface()) {
107            return true;
108        }
109        return false;
110    }
111
112    protected RoutesBuilder instantiateBuilder(Class<? extends RoutesBuilder> type) throws IllegalAccessException, InstantiationException {
113        return camelContext.getInjector().newInstance(type);
114    }
115}