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.impl;
018
019 import org.apache.camel.CamelContext;
020 import org.apache.camel.Component;
021 import org.apache.camel.Exchange;
022 import org.apache.camel.spi.ComponentResolver;
023 import org.apache.camel.util.FactoryFinder;
024 import org.apache.camel.util.NoFactoryAvailableException;
025
026 /**
027 * The default implementation of {@link ComponentResolver} which tries to find
028 * components by using the URI scheme prefix and searching for a file of the URI
029 * scheme name in the <b>META-INF/services/org/apache/camel/component/</b>
030 * directory on the classpath.
031 *
032 * @version $Revision: 563607 $
033 */
034 public class DefaultComponentResolver<E extends Exchange> implements ComponentResolver<E> {
035 protected static final FactoryFinder COMPONENT_FACTORY =
036 new FactoryFinder("META-INF/services/org/apache/camel/component/");
037
038 public Component<E> resolveComponent(String name, CamelContext context) {
039 Class type;
040 try {
041 type = COMPONENT_FACTORY.findClass(name);
042 } catch (NoFactoryAvailableException e) {
043 return null;
044 } catch (Throwable e) {
045 throw new IllegalArgumentException("Invalid URI, no Component registered for scheme : "
046 + name, e);
047 }
048 if (type == null) {
049 return null;
050 }
051 if (Component.class.isAssignableFrom(type)) {
052 return (Component<E>)context.getInjector().newInstance(type);
053 } else {
054 throw new IllegalArgumentException("Type is not a Component implementation. Found: "
055 + type.getName());
056 }
057 }
058 }