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.blueprint;
018
019import java.lang.reflect.Modifier;
020import java.util.List;
021import java.util.Set;
022
023import org.apache.camel.RoutesBuilder;
024import org.apache.camel.spi.PackageScanClassResolver;
025import org.osgi.service.blueprint.container.BlueprintContainer;
026import org.osgi.service.blueprint.reflect.BeanMetadata;
027import org.slf4j.Logger;
028import org.slf4j.LoggerFactory;
029
030/**
031 * A helper class which will find all {@link org.apache.camel.builder.RouteBuilder} instances on the classpath
032 */
033public class PackageScanRouteBuilderFinder {
034    private static final Logger LOG = LoggerFactory.getLogger(PackageScanRouteBuilderFinder.class);
035    private final BlueprintCamelContext camelContext;
036    private final String[] packages;
037    private final PackageScanClassResolver resolver;
038    private final BlueprintContainer blueprintContainer;
039
040    public PackageScanRouteBuilderFinder(BlueprintCamelContext camelContext, String[] packages, ClassLoader classLoader,
041                                         PackageScanClassResolver resolver) {
042        this.camelContext = camelContext;
043        this.blueprintContainer = camelContext.getBlueprintContainer();
044        this.packages = packages;
045        this.resolver = resolver;
046        // add our provided loader as well
047        resolver.addClassLoader(classLoader);
048    }
049
050    /**
051     * Appends all the {@link org.apache.camel.builder.RouteBuilder} instances that can be found on the classpath
052     */
053    public void appendBuilders(List<RoutesBuilder> list) throws IllegalAccessException, InstantiationException {
054        Set<Class<?>> classes = resolver.findImplementations(RoutesBuilder.class, packages);
055        for (Class<?> aClass : classes) {
056            LOG.trace("Found RouteBuilder class: {}", aClass);
057
058            // certain beans should be ignored
059            if (shouldIgnoreBean(aClass)) {
060                LOG.debug("Ignoring RouteBuilder class: {}", aClass);
061                continue;
062            }
063
064            if (!isValidClass(aClass)) {
065                LOG.debug("Ignoring invalid RouteBuilder class: {}", aClass);
066                continue;
067            }
068
069            // type is valid so create and instantiate the builder
070            RoutesBuilder builder = instantiateBuilder(aClass);
071            LOG.debug("Adding instantiated RouteBuilder: {}", builder);
072            list.add(builder);
073        }
074    }
075
076    /**
077     * Allows for ignoring beans that are explicitly configured in the Spring XML files
078     */
079    protected boolean shouldIgnoreBean(Class<?> type) {
080        for (Object metadataObject : blueprintContainer.getMetadata(BeanMetadata.class)) {
081            BeanMetadata metadata = (BeanMetadata) metadataObject;
082            if (BeanMetadata.SCOPE_SINGLETON.equals(metadata.getScope())) {
083                Object bean = blueprintContainer.getComponentInstance(metadata.getId());
084                if (type.isInstance(bean)) {
085                    return true;
086                }
087            }
088        }
089        return false;
090    }
091
092    /**
093     * Returns <tt>true</tt>if the class is a public, non-abstract class
094     */
095    protected boolean isValidClass(Class<?> type) {
096        // should skip non public classes
097        if (!Modifier.isPublic(type.getModifiers())) {
098            return false;
099        }
100
101        if (!Modifier.isAbstract(type.getModifiers()) && !type.isInterface()) {
102            return true;
103        }
104        return false;
105    }
106
107    protected RoutesBuilder instantiateBuilder(Class<?> type) throws IllegalAccessException, InstantiationException {
108        return (RoutesBuilder) camelContext.getInjector().newInstance(type);
109    }
110}