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.NoFactoryAvailableException; 022 import org.apache.camel.spi.ComponentResolver; 023 import org.apache.camel.util.FactoryFinder; 024 import org.apache.commons.logging.Log; 025 import org.apache.commons.logging.LogFactory; 026 027 /** 028 * The default implementation of {@link ComponentResolver} which tries to find 029 * components by using the URI scheme prefix and searching for a file of the URI 030 * scheme name in the <b>META-INF/services/org/apache/camel/component/</b> 031 * directory on the classpath. 032 * 033 * @version $Revision: 752464 $ 034 */ 035 public class DefaultComponentResolver implements ComponentResolver { 036 protected static final FactoryFinder COMPONENT_FACTORY = 037 new FactoryFinder("META-INF/services/org/apache/camel/component/"); 038 private static final transient Log LOG = LogFactory.getLog(DefaultComponentResolver.class); 039 040 @SuppressWarnings("unchecked") 041 public Component resolveComponent(String name, CamelContext context) { 042 Object bean = null; 043 try { 044 bean = context.getRegistry().lookup(name); 045 if (bean != null && LOG.isDebugEnabled()) { 046 LOG.debug("Found component: " + name + " in registry: " + bean); 047 } 048 } catch (Exception e) { 049 LOG.debug("Ignored error looking up bean: " + name, e); 050 } 051 if (bean != null) { 052 if (bean instanceof Component) { 053 return (Component) bean; 054 } 055 // we do not throw the exception here and try to auto create a component 056 } 057 Class type; 058 try { 059 type = COMPONENT_FACTORY.findClass(name); 060 } catch (NoFactoryAvailableException e) { 061 return null; 062 } catch (Exception e) { 063 throw new IllegalArgumentException("Invalid URI, no Component registered for scheme: " + name, e); 064 } 065 if (type == null) { 066 return null; 067 } 068 if (LOG.isDebugEnabled()) { 069 LOG.debug("Found component: " + name + " via type: " + type.getName() + " via: " + COMPONENT_FACTORY.getPath() + name); 070 } 071 if (Component.class.isAssignableFrom(type)) { 072 return (Component) context.getInjector().newInstance(type); 073 } else { 074 throw new IllegalArgumentException("Type is not a Component implementation. Found: " + type.getName()); 075 } 076 } 077 }