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