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.blueprint;
018
019 import java.lang.reflect.Modifier;
020 import java.util.List;
021 import java.util.Set;
022
023 import org.apache.camel.RoutesBuilder;
024 import org.apache.camel.spi.PackageScanClassResolver;
025 import org.apache.commons.logging.Log;
026 import org.apache.commons.logging.LogFactory;
027 import org.osgi.service.blueprint.container.BlueprintContainer;
028 import org.osgi.service.blueprint.reflect.BeanMetadata;
029
030 /**
031 * A helper class which will find all {@link org.apache.camel.builder.RouteBuilder} instances on the classpath
032 *
033 * @version $Revision$
034 */
035 public class PackageScanRouteBuilderFinder {
036 private static final transient Log LOG = LogFactory.getLog(PackageScanRouteBuilderFinder.class);
037 private final BlueprintCamelContext camelContext;
038 private final String[] packages;
039 private final PackageScanClassResolver resolver;
040 private final BlueprintContainer blueprintContainer;
041 // private final BeanPostProcessor beanPostProcessor;
042
043 public PackageScanRouteBuilderFinder(BlueprintCamelContext camelContext, String[] packages, ClassLoader classLoader,
044 /*BeanPostProcessor postProcessor,*/ PackageScanClassResolver resolver) {
045 this.camelContext = camelContext;
046 this.blueprintContainer = camelContext.getBlueprintContainer();
047 this.packages = packages;
048 // this.beanPostProcessor = postProcessor;
049 this.resolver = resolver;
050 // add our provided loader as well
051 resolver.addClassLoader(classLoader);
052 }
053
054 /**
055 * Appends all the {@link org.apache.camel.builder.RouteBuilder} instances that can be found on the classpath
056 */
057 public void appendBuilders(List<RoutesBuilder> list) throws IllegalAccessException, InstantiationException {
058 Set<Class<?>> classes = resolver.findImplementations(RoutesBuilder.class, packages);
059 for (Class aClass : classes) {
060 if (LOG.isTraceEnabled()) {
061 LOG.trace("Found RouteBuilder class: " + aClass);
062 }
063
064 // certain beans should be ignored
065 if (shouldIgnoreBean(aClass)) {
066 if (LOG.isDebugEnabled()) {
067 LOG.debug("Ignoring RouteBuilder class: " + aClass);
068 }
069 continue;
070 }
071
072 if (!isValidClass(aClass)) {
073 if (LOG.isDebugEnabled()) {
074 LOG.debug("Ignoring invalid RouteBuilder class: " + aClass);
075 }
076 continue;
077 }
078
079 // type is valid so create and instantiate the builder
080 RoutesBuilder builder = instantiateBuilder(aClass);
081 // if (beanPostProcessor != null) {
082 // Inject the annotated resource
083 // beanPostProcessor.postProcessBeforeInitialization(builder, builder.toString());
084 // }
085 if (LOG.isDebugEnabled()) {
086 LOG.debug("Adding instantiated RouteBuilder: " + builder);
087 }
088 list.add(builder);
089 }
090 }
091
092 /**
093 * Lets ignore beans that are explicitly configured in the Spring XML files
094 */
095 protected boolean shouldIgnoreBean(Class<?> type) {
096 for (BeanMetadata metadata : blueprintContainer.getMetadata(BeanMetadata.class)) {
097 if (BeanMetadata.SCOPE_SINGLETON.equals(metadata.getScope())) {
098 Object bean = blueprintContainer.getComponentInstance(metadata.getId());
099 if (type.isInstance(bean)) {
100 return true;
101 }
102 }
103 }
104 return false;
105 }
106
107 /**
108 * Returns true if the object is non-abstract and supports a zero argument constructor
109 */
110 protected boolean isValidClass(Class type) {
111 if (!Modifier.isAbstract(type.getModifiers()) && !type.isInterface()) {
112 return true;
113 }
114 return false;
115 }
116
117 @SuppressWarnings("unchecked")
118 protected RoutesBuilder instantiateBuilder(Class type) throws IllegalAccessException, InstantiationException {
119 return (RoutesBuilder) camelContext.getInjector().newInstance(type);
120 }
121 }